A healthy, balanced diet will help provide the nutrients you and your baby need during the pregnancy and after the birth.
For a healthy, balanced diet and information about serving sizes, follow Canadaâ€™s Food Guide. This will help you have enough energy and most of the nutrients you need. The guide recommends a daily intake of the following foods:
- Vegetables and Fruit (seven to eight servings).
- Grain Products (six to seven servings).
- Milk and Alternatives (two to four servings).
- Meat and Alternatives (two servings).
In the second and third trimesters, you will need slightly more calories, protein, vitamins, and minerals. Add an extra two or three servings per day from any food group. Here are a few examples of foods you can add to your meals and snacks:
- Hummus, whole-wheat pita and carrots, or
- A bowl of of whole-grain breakfast cereal with a cup of milk and a banana, or
- A piece of cheese and a slice of of whole-grain bread, or
- A mixture of nuts and dried fruit and a hard-boiled egg.
Take a multivitamin daily before and during your pregnancy.
A daily multivitamin provides important vitamins and minerals, including folic acid and iron. Some women need more folic acid or iron. It is important to take only what is recommended by your health care provider. Check the label on your multivitamin to make sure it contains what and how much your health care provider recommends. Not all prenatal vitamins and multivitamins are the same.
Folic acid helps cells develop and reduces the risk of some birth defects. Folic acid is important early in pregnancy. Folic acid is recommended for:
- All women who could get pregnant.
- All pregnant women.
- All breastfeeding women.
Pregnant women often have difficulty getting enough iron from their food. A daily multivitamin can help you get enough iron. Talk to your health care provider if you have side effects from the multivitamin.
Some foods are unsafe during pregnancy.
Some foods pose a risk during pregnancy.
- Foods such as fully-cooked meat, poultry, and fish; canned pates and meats; pasteurized milk products and hard cheese.
- Fish with lower levels of mercury (such as canned light tuna, shell fish, salmon, and trout).
- Milk, water, or decaffeinated coffee and tea.
- Foods most likely to cause listeriosis (such as raw or undercooked meat, poultry, and fish; deli meats; and raw or unpasteurized milk products, fruit juices, or cider).
- Fish containing high levels of mercury (such as fresh/frozen tuna, shark, swordfish, marlin, orange roughy, and escolar).
- Excess caffeine, have no more than 300 mg/day (i.e., two to three cups of coffee).
- Liver and liver products, due to their high concentrations of vitamin A.
Discuss the safety of herbal teas, artificial sweeteners, and natural health products with your health care provider.
Weight gain is normal and healthy during pregnancy. Weight gain recommendations vary depending on different factors.
It is important to gain a healthy amount of weight for you and your growing baby. This amount depends on your weight before you were pregnant and other factors (e.g. teen pregnancy, pregnant with more than one baby, etc.) The amount of weight you gain includes the weight of your baby, your uterus, the amniotic fluid, etc. A healthy diet plus physical activity during pregnancy will help you gain weight gradually.
There are risks to gaining too much or too little weight during your pregnancy. Talk to your health care provider about how much weight you should gain.
It is important to pay attention to how quickly you gain weight. Weight gain is usually slow during the first three months. Most weight gain will happen in the second and third trimesters. Gaining weight at a steady pace is a sign of a healthy pregnancy. Talk to your health care provider if you are gaining a lot more than 0.4 kg (1 pound) a week, or a lot less.
Learn more about nutrition and healthy weight gain in pregnancy.
You can find out more about nutrition and healthy weight gain in pregnancy from the following resources. More suggestions can be found in the Resources and Links section.
About Healthy Eating During Pregnancy
A healthy and varied diet contributes to a pregnant woman’s health and helps meet the demands of her changing body. It also provides the calories and nutrients needed for fetal growth and development. This allows the expectant mother and her baby to store and use nutrients they need during the pregnancy and during the postnatal period.1
A healthy diet during pregnancy is based on Eating Well with Canada’s Food Guide and includes a variety of:
- Vegetables and fruits, with a focus on green and yellow/orange choices like spinach, broccoli, kale, sweet potato, carrots, mango, and apricots.
- Whole-grains like brown or wild rice, whole-wheat breads and pastas, or quinoa.
- Pasteurized milk and milk alternatives, including yogurt and cheese. A fortified soy beverage is also a suitable choice. Low-fat choices are lower in saturated fats.
- Meats and alternatives like lean meats, chicken, and fish; tofu; legumes such as lentils, chickpeas, or beans as well as nuts and seeds or eggs.
- Canada’s Food Guide recommends at least two servings of fish each week.
- Include healthy fats such as vegetable oils like canola oil, olive oil, or sunflower oil.
- Minimize foods with limited nutritional value, high in salt, fat, and sugars like cakes, chips, ice cream, or fast foods.
- Canada’s Food Guide includes milk and meat alternatives making it an appropriate tool for vegetarian pregnant women to follow.2
In general, Canada’s Food Guide recommends that women between the ages of 19 â€“ 50 enjoy:
- Seven to eight servings of Vegetables and Fruit.
- Six to seven servings of Grain Products.
- Two servings of Milk and Alternatives.
- Two servings of Meat and Alternatives.2
Serving size examples according to Canadaâ€™s Food Guide
Vegetables and Fruit
- 125 mL (1/2 cup) of cooked or raw vegetables.
- 125 mL (1/2 cup) 100% vegetable juice.
- 250 mL (1 cup) of leafy, raw vegetables.
- 125 mL (1/2 cup) of fresh, frozen, or canned fruit.
- 35 grams (one slice) of bread.
- 45 grams (half) of a bagel.
- 35 grams (half) of a pita, tortilla, naan, or other flat bread.
- 125 mL (1/2 cup) cooked grains like rice, pasta, quinoa, or barley.
- 30 grams of cold breakfast cereal; see the side panel for exact amounts. Different cereals will take up more volume depending on how dense they are.
- 175 mL (3/4 cup) of cooked cereal like oatmeal.
Milk and Alternatives
- 250 mL (1 cup) of fluid milk or fortified soy beverage.
- 125 mL (1/2 cup) evaporated milk.
- 175 grams (3/4 cup) of yogurt or kefir.
- 50 grams (1.5 ounces) of cheese.
Meat and Alternatives
- 75 grams (2.5 ounces or 1/2 cup) of cooked meat, chicken, fish, shellfish, or poultry.
- 175 mL (3/4 cup) of cooked legumes like lentils, split peas, or any type of bean (e.g., kidney beans, navy beans, black beans).
- 175 mL (3/4 cup) tofu.
- Two eggs.
- 30 mL (2 Tablespoons) of peanut or other nut/seed butters like almond or cashew butter or tahini (sesame seed taste).
- 60 mL (1/4 cup) of shelled nuts or seeds.
Food servings during pregnancy
Nutrient and calorie needs change throughout pregnancy. The recommended number of servings is the same during the first trimester of pregnancy (i.e., for the first 14 weeks). During the second and third trimesters, pregnant women need two to three extra Food Guide servings per day from any of the four food groups.2
Tips to maintaining a healthy diet
- Enjoy three meals per day and snacks if required. This helps to maintain energy levels throughout the day.2
- Avoid skipping meals. Include breakfast to prevent hunger later in the day.1,2
- Drink plenty of fluids to maintain proper hydration. Aim for 3.0 litres, or about 12 cups, of total fluid from a variety of healthy beverages each day.5 Healthy choices include milk, water, or 100% juice.2,3
- Aim to meet your dietary fibre needs of 28 grams per day.5 Dietary sources of fibre include whole-grains, legumes, nuts and seeds, and fruits and vegetables. This aids in digestion and helps to avoid constipation.3,4
See the Resources and Links section for more information about the recommendations in Canada’s Food Guide.
Nutritional Requirements during Pregnancy
Nutrient requirements increase during pregnancy; this helps support fetal and maternal growth and development. Due to changes in maternal metabolism and hormonal changes, nutrients are used more efficiently and the recommended intake of some nutrients remains the same during pregnancy when compared to a non-pregnant state. Calcium is an example of a nutrient whose requirement remains the same. The requirements for other nutrients like iron and folic acid change as a result of pregnancy and are of particular interest.3,5,6
A woman’s caloric needs increase gradually throughout pregnancy. During the first trimester, calorie needs remain the same as a womanâ€™s pre-pregnant requirements. Calorie needs increase at the start of the second trimester (i.e., from the 15th week).2
On average, pregnant women need approximately:
- 340 extra calories per day during the second trimester.5
- 452 extra calories per day during the third trimester.5
These recommendations are based on the average energy needs of a pregnant woman. Energy requirements for pregnant women who are overweight, obese, and underweight or who have high levels of physical activity are unknown.7 The actual number of additional calories may also vary depending on a womanâ€™s pre-pregnant weight.
Women who are underweight (BMI < 18.5) before pregnancy may need more calories than women who are within a healthy BMI range. Women who are overweight or obese (BMI â‰¥ 25) may need fewer additional calories than the recommended average.8
Meeting caloric needs
The extra calories needed during pregnancy translate into two or three extra food guide servings. They can come from any of the four food groups.
Here are four examples of snacks that provide 350 â€“ 450 extra calories:
- A small home-made muffin, yogurt, and an apple.
- A bowl of breakfast cereal, a cup of milk, and a banana.
- A bowl of vegetable soup, a piece of cheese, and a slice of bread.
- Unsalted mixed nuts with dried fruit, an egg, and half a bagel.9
A mother’s personal preferences, culture, or financial situation can dictate what foods are added. Choices may also be based on nutritional gaps noticed in her diet. For example, if a woman does not normally eat the recommended number of servings of Milk and Alternatives, she may choose foods from this food group to increase her calorie and nutrient intake.
Canada’s Food Guide provides most of the nutrients women need. Use Canada’s Food Guide as a teaching tool to compare the expectant motherâ€™s current diet with the recommendations set out within the Food Guide. For example, does her diet include foods from each of the four food groups? Does it include the suggested number of Food Guide servings and proper serving sizes? Determine what adjustments should be made.
Not all pregnant women start their pregnancy with the same nutritional reserves. Some women are at greater risk for nutritional deficiencies and may have greater needs than others. Depending on the situation, the health care professional can discuss suitable community resources to help (e.g., programs offering integrated prenatal and early childhood services to vulnerable families, free dietary advice phone advice, or associations for people with allergies) and refer them to a registered dietitian if necessary.
Proteins are components of nearly all cells, including the cells that make up our blood, muscles, and vital organs. Enzymes, hormones, and antibodies are also comprised of proteins. As well, proteins are involved in cell formation, function, and maintenance. During pregnancy, they are essential to fetal and placental development as well as to blood-volume expansion.
Protein requirements increase as the pregnancy progresses.
During the first half of pregnancy (the first 20 weeks), a womanâ€™s protein needs remain at 0.8 gram/kg/day (about 46 grams).5
The recommended intake for the second half of pregnancy (from the 20th week until delivery) is 1.1 grams/kg/day (about 71 grams per day).5
According to the most-recent Canadian Community Healthy Survey, over 99 percent of Canadian adults consumed adequate amounts of protein to meet their needs. In Ontario 99.2 percent to 99.6 percent of adult women met their needs for dietary protein.10
Dietary sources of protein
Protein can be found in varying degrees in each of the four food groups. Primary sources of protein can be found in the Meats and Alternatives food group and the Milk and Alternatives food group. This includes red meats, poultry, fish, seafood, legumes, eggs, nuts and seeds as well as milk, soy beverage, yogurt, and cheese. Smaller amounts are found in the Grain Products food group as well as the Vegetables and Fruit food group.9
Data from Health Canada (2010). Canadian Nutrient File, Health Canada9
Calcium is a mineral involved in the formation and maintenance of bones and teeth. It also plays a role in nervous system and muscle function, as well as in blood coagulation. The body makes various adjustments to calcium metabolism during pregnancy. This allows for better absorption of the mineral as well as reduced excretion from the kidneys, which enhances fetal utilization of calcium to help form the skeletal system.11
Calcium requirements remain the same during pregnancy as compared to a pre-pregnant state. Recommended daily requirements are defined as 1,000 mg per day.5
Dietary sources of calcium
The following are the main sources of calcium:
- Milk and milk alternatives, including milk, yogurt, cheese, and fortified soy beverages.
- Foods prepared with milk and milk alternatives, including puddings, cheese dishes, and soups containing milk or cream.9
Other dietary sources include:
- Broccoli and dark-green, leafy vegetables like kale, collards, and mustard greens.
- Almonds, sesame seeds, and tahini.
- Canned salmon and sardines with the bones.
- Firm and extra-firm tofu, prepared with calcium sulphate.9
Health Canada (2010), Canadian Nutrient File, Health Canada9
Vitamin D plays an important role in calcium metabolism and in bone and tooth health. It is also involved in cell-growth regulation, immunity, and cell metabolism. A large number of studies have been published in recent years on the link between vitamin D and cancer, autoimmune diseases, and cardiovascular diseases; however, a clear benefit for vitamin D supplements has not been established.12,13,14,15,16
The recommended dietary intake for vitamin D in pregnancy is 15 micrograms (Âµg) or 600 international units (IU) per day.17 Vitamin D is not widely found in many dietary sources, therefore, obtaining all our needs through food can be challenging.
Health Canada encourages pregnant women to follow the recommendations in Eating Well with Canada’s Food Guide, stressing the need to consume 500 mL (2 cups or 16 ounces) of milk or fortified soy beverage daily.2
Dietary sources of vitamin D
Dietary sources of vitamin D include the following:
- Cow’s milk. Vitamin D fortification is mandatory in Canada.
- Vitamin D fortified goatâ€™s milk. The fortification of goatâ€™s milk is optional in Canada. Consumers should be encouraged to read labels.
- Fortified soy, rice, and almond beverages.
- Fatty fish such as salmon, trout, and sardines.
Source Health Canada (2010), Canadian Nutrient File, Health Canada9
Vitamin B6 is a water-soluble vitamin and is also known as pyridoxine. The body uses vitamin B6 to make and store protein and glycogen. Vitamin B6 helps to form hemoglobin, which transports oxygen throughout the body. Vitamin B6 is involved in the metabolism of neurotransmitters and helps in the formation of the myelin sheaths of all nerve cells. It is also essential for proper fetal development.8
Although some studies have suggested that a vitamin B6 supplement may reduce the incidence of pre-eclampsia in pregnant women or improve newborns’ Apgar scores, a systematic review reveals no clinical benefits from vitamin B6 supplementation during pregnancy.18
The recommended dietary intake for vitamin B6 in pregnancy is 1.9 mg per day. This is considered an adequate intake.5 This vitamin is found in many different foods and can be obtained readily in a vegetarian and vegan diet.
Dietary sources of vitamin B6
Dietary sources of vitamin B6 include the following:
- Meat, fish, and poultry.
- Legumes like lentils, split peas, and kidney beans.
- Some vegetables and fruits like banana, Irish and sweet potato, and avocado.
- Dried fruits like prunes, dates, and figs.
- Grains like oatmeal and wheat bran.
- Nuts like pistachios and different seeds like sesame and sunflower.9
A number of pregnancy-related studies have been conducted on the consumption of fatty acids and in particular, omega-3 fatty acids. They reveal that these fatty acids are essential to fetal development, especially docosahexaenoic acid (DHA).
DHA concentration in the fetal brain increases very quickly during pregnancy.19 DHA is found in cell membranes, including nervous tissue and the retina. DHA plays a role in gene expression as well as brain, nerve, and visual functioning.20
There are three types of omega-3 fatty acids:
- ALA (alpha-linolenic acid).
- EPA (eicosapentaenoic acid).
- DHA (docosahexaenoic acid).
Our body can form EPA and DHA from ALA; therefore, EPA and DHA are not considered essential nutrients. There is no established Dietary Reference Intakes for these two fatty acids.
ALA is the only omega-3 fatty acid that is considered to be essential, meaning we must obtain it from foods. The established adequate intake for ALA during pregnancy is 1.4 grams per day.5
Dietary sources of omega-3 fatty acids
Dietary sources of omega-3 fatty acids include the following:
- Fatty fish like salmon, trout, mackerel, sardines, and herring.
- Some seafood like mussels and oysters.
- Flaxseed and flaxseed oil.
- Soy beans and soybean oil.
- Canola oil.
- Some seaweed.9
A healthy diet should stress healthier types of unsaturated fats like polyunsaturated and monounsaturated fats, including polyunsaturated fats like omega-3 and omega-6 fatty acids.21
Eating fish at least twice a week is recommended.2 Other methods to ensure adequate omega-3 intake include cooking with canola oil, adding ground flaxseed to cereal in the morning, or baking with or snacking on walnuts.9
Source Health Canada (2010), Canadian Nutrient File, Health Canada9
Folate, or vitamin B9, is part of the B-vitamin family and is naturally present in different foods. The synthetic form, folic acid, is found in fortified foods and supplements. The term “dietary folate” describes all forms of folate present in foods, including natural folate and the folic acid in fortified foods.
Folate plays an important role in cell division, amino acid production, and the production of certain nucleic acids, such as DNA. During periods of rapid growth, such as pregnancy, folate plays a part in new cell formation. This nutrient also supports blood-volume expansion in pregnant women as well as maternal and fetal tissue growth.22,23
Given the high rate of cell division and new cell formation during pregnancy, the embryo and fetus are more sensitive to folate deficiency and to errors in its metabolism.23 Folic acid deficiency is linked with an increased risk of birth defects, including neural tube defects.24,25
The recommended intake during pregnancy is 600 micrograms (Âµg)/0.6 milligrams (mg) of dietary folate per day.5 Most pregnant women in North America have difficulty getting that amount of folate from food sources alone.
In order to reduce the risk of neural tube defects and to meet their higher folate needs during pregnancy, all pregnant women and women who wish to become pregnant should take a daily multivitamin containing 400 Âµg (0.4 mg) of folic acid.22
Although this universal recommendation applies to most pregnant women, some have more specific needs. The Society of Obstetricians and Gynaecologists of Canada, together with the Motherisk program, has proposed adjustments to take into account the various factors that may affect folic acid intake.26
Folic acid intake recommendations
1. Women with:
- Low-risk, planned pregnancies and high compliancy rates.
A folate-rich diet along with the use of a daily multivitamin containing 0.4 â€“ 1.0 mg of folic acid for at least three months prior to conception and then throughout the pregnancy and the postpartum period (for four to six weeks, or as long as they continue breastfeeding).26
2. Women with the following risk factors:
- A previous history of giving birth to an infant with a neural tube defect.
- An immediate family member with a neural tube defect, including maternal or paternal history of a neural tube defect.
- Ethnic backgrounds known to be at greater risk for having a child with a neural tube defect (e.g., Sikhs).
- Epilepsy, insulin-dependent diabetes, or obesity (BMI > 35).
A folate-rich diet along with the use of daily multivitamin containing 5 mg of folic acid for at least three months prior to conception and then for 10 â€“ 12 weeks after conception. This can be followed by the use of a daily prenatal multivitamin containing 0.4 â€“ 1.0 mg of folic acid throughout the pregnancy and during the postnatal period (for four to six weeks after the birth, or as long as they continue breastfeeding).26
3. Women with the following risk factors:
- Low-compliancy rate with medical prescriptions.
- Poor diet.
- Lack of contraception.
- Drug or alcohol use.
There is potential benefit in these women receiving birth defect prevention counselling (with referral to a specialist if they wish). This should occur at least three months prior to becoming pregnant.
A folate-rich diet and use of a daily multivitamin containing 5 mg of folic acid throughout the pregnancy and during the postnatal period (for four to six weeks after the birth, or as long as they continue breastfeeding).26
Folic acid supplement versus multivitamin use
The use of a multivitamin is preferable over the use of a single-nutrient folic acid supplement. A multivitamin can provide iron and folic acid as well as other important nutrients.
A number of recent studies have shown that the use of a multivitamin containing folic acid can:
- Decrease the risk of birth defects other than neural tube defects, including cardiovascular defects and defects affecting the limbs.
- Help protect against other problems, such as cleft lips or palates.
- Decrease the risk of pre-eclampsia in pregnant women.4,27,28
Taking a multivitamin has also been shown to be preferable over the use of different supplements providing one or two single micro-nutrients.29,30,31
Studies among women (those using and those not using a folic acid supplement) reveal that:
- Knowledge of the benefits of folic acid increases the likelihood of supplement use, both before and during pregnancy.32
- Women who have discussed the use of folic acid with a health care professional are more likely to take a supplement and to take it regularly (at least four days a week).23,33
Dietary sources of folate
Dietary sources of folate include the following:
- Fortified grain products such as breads, cereals, and pastas.
- Dark-green vegetables like spinach, romaine lettuce, broccoli, and Brussels sprouts.
- Legumes, including lentils and dried beans.
- Oranges and orange juice.9
Source Health Canada (2010), Canadian Nutrient File, Health Canada9
*Suggested serving size
Iron is a mineral and is an essential nutrient. It is an integral part of several proteins, including hemoglobin found in red blood cells and is a part of many different enzymes. It plays an important role in oxygen delivery and energy metabolism. Iron is also involved in several vital physiological processes, such as cell-growth regulation and cell differentiation.
The role of iron during pregnancy explains the increase in iron requirements during pregnancy.
Iron aids in the following processes:
- Expansion of maternal blood volume and hemoglobin mass.
- Supporting fetal and placental growth.
- Building fetal iron stores required to support growth in the first six months of life.34
Iron deficiency in pregnancy
In pregnancy, iron deficiency decreases serum hemoglobin concentration resulting in a decrease of oxygen delivery from the maternal lungs to fetal tissues.
Iron is an immunoregulator; iron deficiency can suppress immune function.
Iron deficiency may lead to maternal anemia potentially resulting in fatigue, preterm delivery, low birth weight, and the increased the risk of infant mortality.34
The Recommended Dietary Allowance for pregnancy is 27 mg of iron per day.5 Most pregnant women in North America have difficulty getting that amount of iron from dietary sources alone.
In order to meet their increased iron needs, it is recommended that pregnant women take a daily multivitamin supplement containing 16 â€“ 20 mg of iron.,35
Taking such a supplement on a daily basis increases the amount of hemoglobin in the mother’s blood. Women who take a daily multivitamin can decrease their risk of developing iron-deficiency anemia.36
Note that women who are iron deficient or anemic need medical assessment to determine how much extra supplemental iron they require.
Dietary sources of iron
Dietary sources of iron include the following:
- Meat, poultry, fish, and seafood.
- Iron-fortified grain products such as breads, cereals, cream of wheat, and pastas.
- Legumes including chickpeas, black beans, and lentils.
- Some vegetables and fruits like dried apricots, spinach, snow peas, and potatoes cooked with their skins.
- Nuts, including pecans, pistachios and almonds.9
Source Health Canada (2010), Canadian Nutrient File, Health Canada9Â Â Â Â Â Â Â Â Â *Suggested serving size
Two forms of dietary iron exist:
- Heme iron, which is found only in meat, poultry, fish, and seafood.
- Non-heme iron, which is found in both animal and plant-based foods like vegetables, grain products, eggs, and legumes.
Heme iron is more readily absorbed than non-heme iron.34
Various foods can affect the absorption of iron.
To enhance the absorption of non-heme iron, pregnant woman can:
- Consume foods rich in vitamin C (e.g., orange juice, tomatoes, broccoli, and sweet pepper) at the same time.
- Enjoy meat, poultry, fish, or seafood (even in small quantities) together with non-heme food sources.14
Conversely, some substances in foods may reduce the absorption of iron from plants, especially if they are consumed at the same meal.
These substances include:
- Phenolic compounds found in tea, coffee, and beet leaves.34,37
- Phytates can bind minerals such as iron and affect absorption. They are found in legumes, unprocessed rice and grains, and unleavened breads.34,38
- Calcium supplements and calcium-containing antacids can affect the absorption of both heme and non-heme iron. Iron and calcium supplements should be taken at least one to two hours apart.34,39
Consuming these substances at the same time as iron-containing foods should be avoided.
Potential side effects of iron supplements
Pharmacological doses of iron such as the amounts of iron found in a single-nutrient iron supplement can cause nausea, vomiting, constipation, diarrhea, dark stools, and gastric pain.40 Pregnant women are encouraged to speak with their health care professionals about any side effects they may be experiencing. Other forms or doses can be recommended to help increase tolerance and minimize side effects.
Listeriosis is a food-borne illness. It is caused by Listeria monocytogenes (commonly called Listeria), a bacterium that is widespread in the environment (soil, vegetation, water) and may, in some cases, contaminate foods.
Listeriosis is relatively rare, but some people are more vulnerable than others. Pregnant women are at a 15 to 20 times’ greater risk of contracting the disease than other healthy adults. This vulnerability is due, in large part, to the way the bacterium multiplies. It spreads through intracellular transmission, which protects it against normal immune responses and allows it to cross the placental barrier.
Once colonized, the fetoplacental unit becomes a prime breeding ground for the bacterium.41
Listeriosis infection can have serious consequences during pregnancy, including:
- Miscarriage or stillbirth.
- Premature delivery.
- Poor health outcomes for the newborn.42,43,44,45
Note that for other food-borne illnesses, such as those caused by Salmonella or E. coli, the risk to pregnant women is the same as the risk to healthy members of the general population.
Symptoms and treatment
Pregnant women who contract listeriosis often have benign, flu-like symptoms (e.g., chills, fatigue, headaches, and muscle and joint pain). They should see a their health care provider if they have a fever.
Listeriosis should be suspected if there is no obvious reason for the fever.42,44,45 The disease can be treated effectively with antibiotics. Early treatment of the pregnant woman may prevent the fetus or newborn from becoming infected.42,44,45
Unlike many bacteria, Listeria can survive and sometimes grow on foods stored in the refrigerator. However, the bacterium is destroyed during cooking. Contaminated foods look, smell, and taste normal.44,45
To reduce the risk of contracting listeriosis and other bacterial infections such as those caused by Salmonella or E. coli, it is important for pregnant women to follow general food hygiene and safety tips, like proper food storage and handling precautions.
Pregnant women are advised to take the following precautions:
- Drink only pasteurized milk.
- Avoid soft cheeses like brie, feta, camembert or blue-veined cheeses, queso blanco, or queso fresco. If these cheeses are to be used, they should be used in cooked dishes and cooked to an internal temperature of 74o C.
- Choose cheeses that are safe to eat during pregnancy, such as cheddar, Swiss, or Parmesan.
- Heat deli meats like ham, turkey or chicken breast, or bologna until steaming before eating them. Deli meats in general should be limited due to their high fat and salt content.
- Avoid refrigerated pate, other meat spreads, and smoked seafood.
- Cook eggs thoroughly.
- Avoid undercooked meat or seafood, including sushi.
- Avoid raw sprouts such as alfalfa or other bean sprouts.
- Avoid unpasteurized juice or cider
- Cook all foods properly to destroy bacteria such as Listeria, Salmonella, and E coli. Use a digital food thermometer to check a food’s internal temperature; it the only way to check that food has been cooked properly and reached a safe internal temperature.46
Source: Safe internal cooking temperatures
Mercury is a metal that can be found naturally in the environment. Various industrial practises cause mercury contamination of the air, water, and soil. This mercury is then converted into methyl mercury, the most hazardous form of mercury.
Methyl mercury accumulates in the flesh of fish, which fish sometimes absorb from its surrounding waters, but mainly after eating other smaller fish containing mercury. 47,48 Mercury cannot be removed from fish by cleaning or cooking.49
Concerns over mercury exposure are due, in part, to its toxicity; over 99 percent of mercury found in fish is in the form of methyl mercury. Methyl mercury is highly absorbable. Humans can absorb about 95 percent of mercury found in food.50
Various adverse effects on human health have been observed following exposure to methyl mercury. The severity of these effects depends on the absorbed dose and exposure time. The accumulation of large doses leads to different disorders affecting fine motor skills, attention, verbal learning, and memory. Methyl mercury also crosses the placenta. The fetal brain is particularly vulnerable to methyl mercury. It is important for pregnant women to monitor their predator-fish consumption.47,48
Dietary sources of methyl mercury
The table below lists the preferable fish species and those that should be eaten in moderation or less frequently during pregnancy.
Note: Canadaâ€™s Food Guide recommends at least two servings of fish each week. One serving is 75 grams (2 1/2 oz) or 125 mL (1/2 cup).
Source: Health Canada (2010), Canadian Nutrient File, Health Canada9
Source: Health Canada (2008) Mercury in Fish, Canada
Larger predator fish like shark or swordfish eat large amounts of smaller fish and are considered to be higher-up on the marine food chain allowing them to bio-accumulate methyl mercury. Larger freshwater fish with higher amounts of mercury include bass, walleye, and pike. Smaller fish that feed on insects or plankton tend to have lower amounts of mercury stored in the muscle or flesh of their bodies.48
Tuna: a special case
Canned tuna is a popular fish for many consumers. It is convenient, widely available, and affordable. Therefore, a few distinctions should be made:
- Canned light tuna contains other species of tuna, such as the skipjack tuna, yellowfin tuna, or longtail tuna, whose mercury concentrations are lower. Health Canada has not established any advisory over its consumption.
Pregnant women who eat game fish on a regular basis should check whether any related warnings have been issued in their area by contacting the Ontario Ministry of Natural Resources. To learn more see the Resources and Links section.
Coffee and tea are popular drinks, and their consumption has been the subject of a number of studies. Currently, there are no specific consumption pattern reports for caffeine intakes among Ontario residents.
Studies on caffeine consumption during pregnancy reveal:
- Caffeine consumption is unlikely to lead to birth defects.51
- There is currently not enough evidence to confirm or disprove that caffeine consumption affects birth weight or how a pregnancy will progress.52
Health Canada recommends pregnant women limit their caffeine intake to 300 mg or less per day. This is equal to about two or three cups of coffee per day, or four to six cups of tea each day.53
Dietary sources of caffeine
Dietary sources of caffeine include:
- Black and green tea.
- Some soft drinks (both cola and some non-cola).
- Some energy drinks.
Pregnant women are advised to avoid energy drinks.
Source Health Canada (2010), Canadian Nutrient File, Health Canada9
There is not enough evidence regarding the effects of herbs and herbal teas on fetal growth and development, birth outcomes, or maternal health to draw conclusions.54
Most experts and government agencies, therefore, recommend the following:
- Pregnant women should not take any medication, medicinal plant, or natural health product, except at the recommendation of their health care provider.
- Ginger is an exception to the rule. Its use during pregnancy has been studied (using dosages of 0.5 â€“ 1.5 grams per day) and proven to be effective for relieving morning sickness with no adverse effects reported.54,55
- The following herbal teas are generally considered safe if taken in moderation (i.e., two to three cups per day): citrus peel, peppermint, Echinacea, red raspberry leaf, rosemary, ginger, orange peel and rosehip.8,56,57,58,59,60
Artificial sweeteners are substances that are typically many times sweeter than sugars but do not contain any or as many calories as sugar. Some, such as aspartame are used as food additives. They are added to various commercial food items, in particular, soft drinks, desserts, breakfast cereals, and chewing gum.
Others, such as saccharin and cyclamates, are used as tabletop sweeteners only, meaning that they can only be purchased for personal use, to be added to coffee or other hot drinks and dessert recipes. They are not used as food additives.61,62 Canadian Food and Drug Regulations require food labels to state that saccharin sweeteners not be used by pregnant women unless it is on the advice of their health care provider.82
In Canada, sweeteners are approved for use only after their safety has been assessed and an acceptable daily intake has been determined. The scientific data available at this point reveals that the products currently used as sweeteners in Canada can safely be consumed by the general population, including by pregnant and breastfeeding women.61,62
Pregnant women should be counselled to use these products in moderation since these types of foods may replace nutrient-rich foods that are a good source of energy.63
Natural health products (NHPs) are natural substances that are used for a number of health reasons, including prevention or treatment of an illness, to reduce health risks, or maintain health. They are made from plants, animals, microorganism or marine sources like aquatic plants. These products can be in the form of tablets or capsules, solutions, drops, creams or ointments; these are over-the-counter products. NHPs are popular among Canadians with about 71 percent of Canadians having tried or used these products.64
- Vitamins and minerals.
- Herbal remedies.
- Homeopathic medicine.
- Traditional Chinese and East Indian medicine.
- Amino acids and essential fatty acids.64
Natural Health Products are not risk-free.
To help minimize risk, pregnant and breastfeeding women should:
- Talk to their health care providers including doctors, midwives, pharmacists, dietitians, or naturopaths before taking any products.
- Use approved products. Look for an NHP number on the label (usually an eight-digit number following the initials NHP); this identifies licensed products. To be licensed, a natural health product must be safe, effective, of high quality, and contain detailed label information.
- Read and follow all instructions on a product label.
- Report all unwanted side effects to health care providers and Health Canada.
Vitamin A plays several major roles in the body: it promotes good vision, is involved in bone and tooth growth, contributes to skin and mucous membrane health, and protects against infection. It is important that pregnant women get enough vitamin A to meet their needs.
To avoid confusion, pregnant women should be told that regular dietary vitamin A consumption does not cause any problems. Excess vitamin A is to be avoided.65
Women are encouraged to enjoy a diet that includes foods rich in vitamin A. This can help them meet their needs for adequate amounts of this important nutrient. Adequate amounts are defined as 2567 IU or 770 micrograms per day.5 Excessive amounts can have teratogenic effects.65
Excessive amounts of vitamin A are defined as 10,000 IU or 3000 micrograms per day.5
Women who are pregnant or wish to become pregnant are advised to limit foods with very high retinol concentrations including liver and liver products or avoid excessive amounts from supplemental forms. This is especially important during the first trimester.66,67
Pregnant women should also have no more than one daily dose of a prenatal multivitamin so that they do not exceed the recommended amount of vitamin A.22 Prenatal vitamin supplements containing beta-carotene as the form of vitamin A are safe to take during pregnancy.
Source Health Canada (2010), Canadian Nutrient File, Health Canada9
It is logical to advise pregnant women to eat liver no more than once every two weeks based on the high vitamin content of liver compared to the upper limit set at 3000 micrograms per day. Pregnant women need 1300 micrograms per day.
Source Health Canada (2010), Canadian Nutrient File, Health Canada9
About Weight Gain during Pregnancy
A woman’s pre-pregnant body mass index (BMI) and maternal weight gain both influence fetal growth. They are both linked to birth weight and to other indicators of maternal health outcomes and birth outcomes.68,69
Weight gain is a sensitive topic during pregnancy, and a sensitive approach to counselling is an important aspect of prenatal care. Maternal weight gain encompasses the babyâ€™s weight and the weight of the placenta, uterus, maternal blood volume, amniotic fluid, and growing breast tissue.
Canadian recommendations on maternal weight gain are based on the recommendations of the Institute of Medicine in the United States.8 They offer weight-gain ranges that use a woman’s pre-pregnancy BMI.
Gaining weight within the recommended ranges, as set out in Table 12, is associated with optimal birth outcomes for both the mother and baby. It lowers the risk of maternal complications like gestational diabetes and complications at delivery.70,71
Women can determine their BMI using the BMI calculator on the Health Canada website. By entering their height and pre-pregnancy weight their BMI is calculated automatically. However, women are advised to discuss their weight gain recommendations directly with their health care provider.
Source Health Canada69 and IOM 200970
Concerns over appropriate weight gain during pregnancy arise from the most-recent trends showing a greater percentage of women entering pregnancy overweight or obese. Many women are also gaining too much weight during pregnancy.70,71,72,73,74.75
For more information about healthy weight gain during pregnancy, see the Resources and Links section.
Weight gain during pregnancy is gradual. It is slower in the first trimester with weight gain rates increasing during second and third trimester. Women can gain no weight or can gain up to one to two kilograms in their first trimester. Expected weight gain in the subsequent trimesters is approximately 500 grams per week starting in the 15th week of gestation.72
The amount of weight gained varies from one woman to the next, and sometimes from one pregnancy to the next for the same woman.
Women experiencing excess amounts of weight gain or rapid weight gain may need dietary counselling or advice about physical activity. The same applies to women who gain too little or who lose weight, especially if they started their pregnancy with a low BMI of less than 18.5.76
Causes for Concern
There is growing concern over the increased prevalence of overweight and obese women who become pregnant or women who gain too much weight during pregnancy. This can have negative impacts on the health of the mother and her child. Weight loss or dieting is not recommended during pregnancy.
Women who start their pregnancy overweight are more likely to:
- Deliver by C-section.
- Develop gestational diabetes.68,77,78
Their children are also at greater risk for obesity and obesity-related complications.77,78,79
Excessive weight gain during pregnancy is associated with:
- Increased risk of complications at delivery.
- Increased risk of developing gestational diabetes.
- Excess weight retention after delivery.7,69,70,71,73,75,80,81
Babies whose mothers gain more than the recommended amounts of weight during pregnancy are more likely to:
- Experience excessive fetal growth.
- Develop fetal macrosomia.
The negative health consequences are compounded if a significant weight gain during pregnancy is combined with a high pre-pregnancy BMI.
Having a low pre-pregnant BMI or gaining too little weight during pregnancy is also a cause for concern.
A lack of appropriate weight gain during pregnancy is associated with an increased risk of:
- Giving birth to a baby who is small for their gestational age.
- Neonatal morbidity and mortality.
- Physical and cognitive disabilities.
- Chronic health problems later in life.70,71
The risk is higher for women who begin their pregnancy being underweight.68,73,80
Pregnant women with special circumstances (e.g., multiple pregnancies, teenage pregnancy, nutritional risks, physical or mental illness) require special diet and weight gain recommendations in order to promote a healthy pregnancy.
Professionals are encouraged to refer these women to specialized resources that will be able to offer them personalized nutritional assessment, treatment, and monitoring services.
For more information about referrals, see the Resources and Links section.
Resources & Links
- Society of Obstetricians and Gynaecologists of Canada (SOGC)
- Institute of Medicine (IOM)
Websites: Resources for Clients
- Dietitians of Canada
- Health Canada
- BMI and Pregnancy Weight Gain Calculator
- Common questions and answers regarding mercury in fish
- Eating Well with Canada’s Food Guide
- My Food Guide Servings Tracker (Pregnant Female aged 19 – 50 years)
- The Natural Health Products Ingredient Database
- Report an adverse reaction to a natural health product
- Ontario Ministry of Community and Social Services
- Ontario Ministry of Environment and Energy
- Public Health Agency of Canada
- Society of Obstetricians and Gynaecologists of Canada (SOGC)
Websites: Resources for Professionals
- Health Canada
- Health Risk Classification According to BMI
- Prenatal Nutrition Guidelines for Health Professionals – Folate Contributes to a Healthy Pregnancy
- Prenatal Nutrition Guidelines for Health Professionals – Background on Canada’s Food Guide
- Prenatal Nutrition Guidelines for Health Professionals: Gestational Weight Gain
- Prenatal Nutrition Guidelines for Health Professionals: Iron.
416-813-6780 (Toronto and GTA)
- Ontario Ministry of Natural Resources and Forestry (fish safety) 1-800-667-1940
- Telehealth OntarioÂ 1-866-797-0000, 1-866-797-0007 (TTY)
Prenatal Education Provider Tools
- Best Start Resource Centre
- Canadaâ€™s Food Guide for Educators and Communicators
Client Resources and Handouts
- Best Start Resource Centre (BSRC)
- Williamson, C. S. (2006). Nutrition in pregnancy. Nutrition Bulletin, 31(1), 28-59.
- Government of Canada. (2014). Eating well with Canadaâ€™s food guide. Retrieved from http://www.healthycanadians.gc.ca/eating-nutrition/food-guide-aliment/index-eng.php
- Health Canada. (2011). Prenatal nutrition. Retrieved from http://www.hc-sc.gc.ca/fn-an/nutrition/prenatal/index-eng.php
- Czeizel, A. E. (2009). Periconceptional folic acid and multivitamin supplementation for the prevention of neural tube defects and other congenital abnormalities. Birth Defects Research Part A: Clinical and Molecular Teratology, 85(4), 260-268.
- Health Canada. (2010). Dietary reference intake tables. Retrieved from http://www.hc-sc.gc.ca/fn-an/nutrition/reference/table/index-eng.php
- De-Regil, L. M., FernÃ¡ndez-Gaxiola, A. C., Dowswell, T., & PeÃ±a-Rosas, J. P. (2010). Effects and safety of periconceptional folate supplementation for preventing birth defects. Cochrane Database of Systematic Reviews, 2006(2). doi:10.1002/14651858.CD007950.pub2.
- Siega-Riz, A. M., Viswanathan, M., Moss, M. K., Deierlein, A., Mumford, S., Knaack, J., Lohr, K. N. (2009). A systematic review of outcomes of maternal weight gain according to the Institute of Medicine recommendations: Birthweight, fetal growth, and postpartum weight retention. American Journal of Obstetrics and Gynecology, 201(4), 339.e1-339.e14. http://dx.DOI.org/10.1016/j.ajog.2009.07.002
- Institute of Medicine. (2009). Weight gain during pregnancy: Reexamining the guidelines. Washington, DC: National Academies Press. Retrieved from http://www.nap.edu/catalog.php?record_id=12584
- Health Canada. (2010). Canadian Nutrient File (CNF) â€“ Search by food. Retrieved from https://food-nutrition.canada.ca/cnf-fce/index-eng.jsp
- Health Canada. (2012). Do Canadian adults meet their nutrient requirements through food intake alone? Retrieved from http://www.hc-sc.gc.ca/fn-an/surveill/nutrition/commun/art-nutr-adult-eng.php#a321
- Mulligan, M. L., Felton, S. K., Riek, A. E., & Bernal-Mizrachi, C. (2009). Implications of vitamin D deficiency in pregnancy and lactation. American Journal of Obstetrics and Gynecology, 202(5) http://dx.doi.org/10.1016/j.ajog.2009.09.002
- Chung, M., Balk, E. M., Brendel, M., Ip, S., Lau, J., . . . & Trikalinos, T. A. (2009, August). Vitamin D and calcium: Systematic review of health outcomes (AHRQ Publication No. 09-E015). Rockville, MD: Agency for Healthcare Research and Quality. Retrieved from http://www.ahrq.gov/downloads/pub/evidence/pdf/vitadcal/vitadcal.pdf
- Kimball, S., Fuleihan, G. E. H., &Vieth, R. (2008). Vitamin D: A growing perspective. Critical Reviews in Clinical Laboratory Sciences, 45(4), 339-414. DOI:10.1080/10408360802165295
- Kovacs, C. S. (2008). Vitamin D in pregnancy and lactation: Maternal, fetal, and neonatal outcomes from human and animal studies. American Journal of Clinical Nutrition, 88(2), 520S-528S.
- Theodoratou, E., Tzoulaki, I., Zgaga, L., & Ionnidis, J. P. (2014). Vitamin D and multiple health outcomes: Umbrella review of systematic reviews and meta-analyses of observational studies and randomized trials. BMJ, 348, g2035. doi: 10.1136/bmj.g2035
- Harvey, N. C., Holroyd, C., Ntani, G., Javaid, K., Cooper, P., Moon, R., . . . Cooper, C. (2014). Vitamin D supplementation in pregnancy: A systematic review. Health Technology Assessment, 18(45), 1-190. doi:10.3310/hta18450
- Ross, A. C., Taylor, C. L., Yaktine, A. L., & Del Valle, H. B. (2010). Dietary reference intakes for calcium and vitamin D. Washington, DC: The National Academies Press.
- Thaver, D., Saeed, M. A., & Bhutta, Z. A. (2006). Pyridoxine (vitamin B6) supplementation in pregnancy. Cochrane Database of Systematic Reviews, 2006(2). DOI: 10.1002/14651858.CD000179.pub2
- Cetin, I., & Koletzko, B. (2008). Long-chain omega-3 fatty acid supply in pregnancy and lactation. Current Opinion in Clinical Nutrition and Metabolic, 11(3), 297-302. doi: 10.1097/MCO.0b013e3282f795e6
- Higdon, J., Angelo, G., & Jump, D.B. (2014). Essential fatty acids. Retrieved from http://lpi.oregonstate.edu/infocenter/othernuts/omega3fa/index.htmL#intro
- Blanchard, D. S. (2006). Omega-3 fatty acid supplementation in perinatal settings. MCN, American Journal of Maternal/Child Nursing, 31(4), 250-256.
- Health Canada. Prenatal nutrition guidelines for health professionals: Folate contributes to a healthy pregnancy. Retrieved from http://www.hc-sc.gc.ca/fn-an/pubs/nutrition/folate-eng.php
- Tam, C., McKenna, K., Goh, Y., Klieger-Grossman, C., Oâ€™Connor, D. L., Einarson, A., & Koren, G. (2009). Periconceptional folic acid supplementation: A new indication for therapeutic drug monitoring. Therapeutic Drug Monitoring, 31(3), 319-326. doi:10.1097/FTD.0b013e31819f3340
- National Institute of Neurological Disorders and Stroke. (2014) Spina bifida fact sheet. Retrieved from https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Spina-Bifida-Fact-Sheet
- De-Regil, L. M., FernÃ¡ndez-Gaxiola, A. C., Dowswell, T., & PeÃ±a-Rosas, J. P. (2010). Effects and safety of periconceptional folate supplementation for preventing birth defects. Cochrane Database of Systematic Reviews, 2010(10), 1-146. DOI:10.1002/14651858.CD007950.pub2
- Wilson, R. D., (2015). Pre-conception folic acid and multivitamin supplementation for the primary and secondary prevention of neural tube defects and other congenital anomalies. Journal of Obstetrics and Gynaecology Canada, 37(6), 534-549. https://doi.org/10.1016/S1701-2163(15)30230-9
- Goh, Y. I., Bollano, E., Einarson, T. R., & Koren, G. (2006). Prenatal multivitamin supplementation and rates of congenital anomalies: A meta-analysis. Journal of Obstetrics and Gynaecology Canada, 28(8), 680-689.
- De-Regil, L. M., FernÃ¡ndez-Gaxiola, A. C., Dowswell, T., PeÃ±a-Rosas, J. P. (2010). Effects and safety of perconceptional folate supplementation for preventing birth defects. Cochrane Database of Systematic Reviews, 2010(10), 1-146.
- Glenville, M. (2006). Nutritional supplements in pregnancy: Commercial push or evidence based? Current Opinion in Obstetrics and Gynecology, 18(6), 642-647.
- Shah, P. S., & Ohlsson, A. (2009). Effects of prenatal multimicronutrient supplementation on pregnancy outcomes: A meta-analysis. Canadian Medical Association Journal, 180(12), E99-108.
- Haider, B. A., Bhutta, Z. A. (2012). Multiple-micronutrient supplementation for women during pregnancy. Cochrane Database of Systematic Reviews, 2012(11), 1-119. doi: 10.1002/14651858.CD004905.pub3
- Public Health Agency of Canada. (2009). What mothers say: The Canadian survey on the experience of motherhood. Ottawa, ON: Author. Retrieved from http://www.birthbythenumbers.org/wp-content/uploads/2012/03/WhatMothersSayReport.pdf
- Morin, P., Demers, K., GiguÃ¨re, C., Tribble, D. S., & Lane, J. (2007). Multivitamin supplement for primary prevention of birth defects: Application of a preventive clinical practice. Canadian Family Physician, 53(12), 2142-2143.
- Health Canada. (2009). Prenatal nutrition guidelines for professionals: Iron contributes to a healthy pregnancy. Retrieved from http://www.hc-sc.gc.ca/fn-an/pubs/nutrition/iron-fer-eng.php
- Cockell, K. A., Miller, D. C., & Lowell, H. (2009). Application of the dietary reference intakes in developing a recommendation for pregnancy iron supplements in Canada. American Journal of Clinical Nutrition, 90(4), 1023-1028.
- PeÃ±a-Rosas, J. P., De-Regil, L. M., Dowswell, T., & Viteri, F. E. (2012). Effects of routine oral iron supplementation with or without folic acid for women during pregnancy. Cochrane Database of Systematic Reviews, 2012(12), 1-529. DOI:10.1002/14651858.CD004736.pub4
- Zijp, I.M., Korver, O., Tijburg, L.B. (2000). Effect of tea and other dietary factors on iron absorption. Critical Reviews in Food Science and Nutrition, 40(5), 371-98. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/11029010
- Hurrell, R.F., Juillerat, M.A., Reddy, M.B., Lynch, S.R., Dassenko, S.A., & Cook, J.D. (1992). Soy protein, phytate, and iron absorption in humans [Abstract]. American Journal of Clinical Nutrition, 56(3), 573-8. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/1503071
- Lim, K. H., Riddell, L. J., Nowson, C. A., Booth, A. O., & Szymlek-Gay, E. A. (2013). Iron and zinc nutrition in the economically-developed world: A review. Nutrients, 5(8), 3184-211. doi:10.3390/nu5083184
- Office of Dietary Supplements. Iron: Dietary supplement fact sheet. (2014). Retrieved from http://ods.od.nih.gov/factsheets/Iron-HealthProfessional/
- Janakiraman, V. (2008). Listeriosis in pregnancy: Diagnosis, treatment, and prevention. Reviews in Obstetrics and Gynecology, 1(4), 179-185. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2621056/
- Bortolussi, R. (2008). Listeriosis: A primer. Canadian Medical Association Journal, 179(8), 795-797. DOI:10.1503/cmaj.081377
- Government of Canada. (2012). Listeria and listeriosis. Retrieved from http://healthycanadians.gc.ca/eating-nutrition/poisoning-intoxication/listeriosis-listeria-listeriose-eng.php
- Listeria Working Group for the Council of Chief Medical Officers of Health. (2010, July 6). Prevention of listeriosis: Considerations for development of public health messages. Waterloo, ON: Canadian Institute of Public Health.
- Lamont, R. F., Sobel, J., Mazaki-Tovi, S., Kusanovic, J. P., Vaisbuch, E., Kim, S. K., . . . Romero, R. (2011). Listeriosis in human pregnancy: A systematic review. Journal of Perinatal Medicine, 39(3), 227-236. doi:10.1515/JPM.2011.035
- Government of Canada. (2012). Listeria and listeriosis. Retrieved from http://healthycanadians.gc.ca/eating-nutrition/poisoning-intoxication/listeriosis-listeria-listeriose-eng.php
- Health Canada. (2008). Human health risk assessment of mercury in fish and health benefits of fish consumption. Retrieved from http://www.hc-sc.gc.ca/fn-an/pubs/mercur/merc_fish_poisson-eng.php#tphp
- Food and Agriculture Organization of the United Nations (FAO). (2010). Fats and fatty acids in human nutrition: Report of an expert consultation. Rome, Italy: Author. Retrieved from http://www.fao.org/docrep/013/i1953e/i1953e00.pdf
- Health Canada. (2008). Mercury in fish. Retrieved from http://www.hc-sc.gc.ca/fn-an/securit/chem-chim/environ/mercur/cons-adv-etud-eng.php
- Scober, S.E., Sinks, T.H., Jones, R. L., Bolger, P. M., McDowell, M., Osterloh, J., Mahaffey, K. R. (2003). Blood mercury levels in US children and women of childbearing age, 1999-2000 [Abstract]. Journal of the American Medical Association, 289(13), 1667-74. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/12672735
- Browne, M. L. (2006). Maternal exposure to caffeine and risk of congenital anomalies: A systematic review. Epidemiology, 17(3), 324-331.
- Jahanfar, S., & Sharifah, H. (2013). Effects of restricted caffeine intake by mother on fetal, neonatal and pregnancy outcome. Cochrane Database of Systematic Reviews, 2013(2). doi: 10.1002/14651858.CD006965.pub3
- Higdon, J. V., & Frei, B. (2006). Coffee and health: A review of recent human research. Critical Reviews in Food Science and Nutrition, 46(2), 101-123.
- Dante, G., Pedrielli, G., Annessi, E., & Facchinetti, F. (2013). Herb remedies during pregnancy: A systematic review of controlled clinical trials. The Journal of Maternal-Fetal & Neonatal Medicine, 26(3), 306-312. doi:10.3109/14767058.2012.722732
- Motherisk (2005). Herbal products. Retrieved from http://www.motherisk.org/prof/mothernature.jsp
- Natural Medicines Comprehensive Database. (2012). Retrieved from http://www.naturaldatabase.com/(S(lesr0d454zc5plfvowxkwg55))/home.aspx?cs=&s=ND
- Perri, D., Dugoua, J. J., Mills, & E., Koren, G. (2006). Safety and efficacy of echinacea (Echinacea augustifolia, e. purpurea and e. pallida) during pregnancy and lactation [Abstract]. Canadian Journal of Clinical Pharmacology,13(3), e262-7. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/17085774
- Health Canada. (2008). Monograph: Echinacea augustifolia. Retrieved from http://webprod.hc-sc.gc.ca/nhpid-bdipsn/monoReq.do?id=78&lang=eng
- Health Canada. (2008). Monograph: Peppermint. Retrieved from http://webprod.hc-sc.gc.ca/nhpid-bdipsn/monoReq.do?id=144&lang=eng
- Simpson, M., Parsons, M., Greenwood, J., & Wade, K. (2001). Raspberry leaf in pregnancy: Its safety and efficacy in labor [Abstract]. Journal of Midwifery and Womenâ€™s Health, 46(2), 51-9. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/11370690
- Health Canada. (2010). Sugar substitutes. Retrieved from http://www.hc-sc.gc.ca/fn-an/securit/addit/sweeten-edulcor/index-eng.php
- Health Canada. (2008). Itâ€™s your health: The safety of sugar substitutes. Retrieved from http://www.hc-sc.gc.ca/hl-vs/iyh-vsv/food-aliment/sugar_sub_sucre-eng.php
- Health Canada. (2007). Questions and answers: Saccharin. Retrieved from http://www.hc-sc.gc.ca/fn-an/securit/addit/sweeten-edulcor/saccharin_qa-qr-eng.php
- Health Canada. (2012). About natural health products. Retrieved from http://www.hc-sc.gc.ca/dhp-mps/prodnatur/about-apropos/cons-eng.php
- Rothman, K. J., Moore, L. L., Singer, M.R., Nguyen, U.S., Mannino, S., & Milunsky, A. (1995). Teratogenicity of high vitamin A intake [Abstract]. New England Journal of Medicine, 333(91), 1369-73. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/7477116
- Mills, J. L., Simpson, J.L., Cunningham, G.C., Conley, M.R., & Rhoads, G.G. (1997). Vitamin A and birth defects [Abstract]. American Journal of Obstetrics and Gynecology, 177(1), 31-6. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/9240579
- Mastroiacovo, P., Mazzone, T., Addis, A., Elephant, E., Carlier, P., Vial, T., . . . Clementi, M. (1999). High vitamin A intake in early pregnancy and major malformations: A multicenter prospective controlled study [Abstract]. Teratology, 59(1), 7-11. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/9988877
- Ay, L., Kruithoff, C. J., Bakker, R., Steegers, E. A., Witteman, J. C., Moll, H. A., . . . Hofman, A. (2009). Maternal anthropometrics are associated with fetal size in different periods of pregnancy and at birth: The Generation R study. BJOG: An International Journal of Obstetrics and Gynaecology, 116(7), 953-963.
- Kelly, C. Y., Clancy, C. M. (2009). Importance of recommendations for gestational weight gain. Journal of Nursing Care Quality, 24(2), 96-99. doi:10.1111/j.1471-0528.2009.02143.x
- Health Canada. (2013, June). Prenatal nutrition guidelines for health professionals: Gestational weight gain. Retrieved from http://www.hc-sc.gc.ca/fn-an/nutrition/prenatal/ewba-mbsa-eng.php#t2
- Institute of Medicine. (2009). Weight gain during pregnancy: Reexamining the guidelines. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/20669500
- Rasmussen, K. M., & Yaktine, A. L. (2009). Weight gain during pregnancy: Reexamining the guidelines. Washington, DC: The National Academies Press.
- Stotland, N. E., Cheng, Y. W., Hopkins, L. M., & Caughey, A. B. (2006). Gestational weight gain and adverse neonatal outcome among term infants. Obstetrics and Gynecology, 108(3 Pt 1), 635-643.
- Kuehn, B. M. (2009). Guideline for pregnancy weight gain offers targets for obese women. Journal of the American Medical Association, 302(3), 241-242.
- Dietz, P. M., Callaghan, W. M., &Sharma, A. J. (2009). High pregnancy weight gain and risk of excessive fetal growth. American Journal of Obstetrics and Gynecology, 201(1), 51-56.
- Stuebe, A. M., Oken, E., & Gillman, M. W. (2009). Associations of diet and physical activity during pregnancy with risk for excessive gestational weight gain. American Journal of Obstetrics and Gynecology, 201(1). doi:10.1016/j.ajog.2009.02.025
- Oken, E. (2009). Maternal and child obesity: The causal link. Obstetrics and Gynecology Clinics of North America, 36(2), 361-377.
- Davis, E., & Olson, C. (2009). Obesity in pregnancy. Primary Care: Clinics in Office Practice, 36(2), 341-356.
- Lau, E. Y., Liu, J., Archer, E., McDonald, S. M., & Liu, J. (2014). Maternal weight gain in pregnancy and risk of obesity among offspring: A systematic review. Journal of Obesity, 2014(524939). doi:10.1155/2014/524939
- Crane, J. M. G., White, J., Murphy, P., Burrage, L., & Hutchens, D. (2009). The effect of gestational weight gain by body mass index on maternal and neonatal outcomes. Journal of Obstetrics and Gynaecology Canada, 31(1), 28-35. Retrieved from http://www.jogc.com/
- Dietz, P. M., Callaghan, W. M., Smith, R., & Sharma, A. J. (2009). Low pregnancy weight gain and small for gestational age: A comparison of the association using 3 different measures of small for gestational age. American Journal of Obstetrics & Gynecology, 201(1). http://dx.doi.org/10.1016/j.ajog.2009.04.045
- Department of Justice Canada. Food and Drug Regulations. Food and Drug Act. Regulations current to November 29, 2011. Retrieved from: http://laws-lois.justice.gc.ca/eng/regulations/C.R.C.,_c._870/FullText.html