Before adopting the U.S. Institute of Medicine (IOM) 2009 recommendations for weight gain during pregnancy, Health Canada and the Expert Advisory Group on National Nutrition Pregnancy Guidelines considered the evidence base for the IOM recommendations as well as findings from the 2006-07 Maternity Experiences Survey (MES).
A summary of each of the following documents was reviewed and considered as part of this process:
Current available evidence supports the use of the IOM recommendations in the Canadian context. However, an important issue will be their implementation as many Canadian women are gaining above the recommended weight gain ranges.
To help support the implementation of the U.S. Institute of Medicine (IOM) recommendations, Health Canada has developed a background document for health care providers as well as sample weight gain tracking charts that can be integrated into existing tools and resources for pregnant women. In addition, a print resource and the Pregnancy Weight Gain Calculator can be used to help women learn more about healthy weight gain during pregnancy.
The previous pregnancy weight gain guidelines recommended that pregnant teens gain at the upper end of the weight range for their pre-pregnancy body mass index (BMI). However, there is growing concern that pregnancy during adolescence may increase the risk of excess weight retention and the development of obesity, particularly if pregnant teens gain at the upper end of the range of their BMI category. Until more is known, teenagers should be advised to stay within the recommended weight gain range for their pre-pregnancy BMI.
The recommended weight gain ranges for pre-pregnancy BMIs of 30 or greater is 5 to 9 kg or 11 to 20 lbs. This range is recommended as a starting point to set weight gain goals for women with a BMI of 35 or greater. For some of these women, it may be acceptable to gain less than the recommended weight. However, it is important that a woman and her health care provider consider the risks and benefits to mother and child of gaining less than 5 kg or 11 lbs throughout pregnancy.
Yes, you can continue taking the multivitamin supplement. An over-the-counter prenatal supplement that provides 27 mg of elemental iron does not pose any significant health risks. However, iron intakes from multivitamin supplements at or above 27 mg (the Recommended Dietary Allowance for iron) are not needed by healthy, iron-replete women whose diets include heme iron, non-heme iron, and vitamin C rich-foods.
The main practical concern is that a woman may stop taking prenatal multivitamin supplements because of gastrointestinal discomfort (such as constipation) that is sometimes associated with supplements that provide higher amounts of iron.
Some formulations of multivitamin supplements that are not specifically targeted to pregnant women contain amounts of folic acid and iron that fall within the recommendations.
Health Canada is working to encourage voluntary reformulation of multivitamin supplements so that in the near future more products which meet the recommendations will be available in the marketplace.
Vegetarians need more iron in their diet than other women because they absorb less iron from the food they eat. Vegetarian diets contain only the non-heme form of iron. How well non-heme iron gets absorbed by the body depends on what other foods are eaten at the same time. Certain foods can help or hinder iron absorption.
Health Canada did not define the amount of supplemental iron that vegetarians need during pregnancy. Canadian survey data did not have sufficient information to determine how much iron comes from vegetarian diets of Canadian women.
If you are vegetarian, it is recommended that you talk to your health care provider early in your pregnancy to get specific advice on your iron needs.
Research has shown that cooking foods in iron pots on a daily basis can increase the non-heme iron content of those foods. The amount of iron released from iron pots varies from meal to meal, and is dependent on the composition of the food being cooked. The acidity and moisture content of the food, and the cooking time, all influence the amount of iron that could be released from iron pots. Therefore, while there is no simple way to determine the amount of iron available to the body through this cooking method, the evidence suggests that consistent use may help to increase total iron intake.
Yes, you can continue taking the supplement. Most women do not need more than the recommended 400 mcg (0.4 mg) of folic acid. However, your health care provider may recommend or prescribe a supplement with a higher amount of folic acid if you are at increased risk of having a baby with a neural tube defect. These supplements are usually recommended to be taken for a short period of time (usually from 3 months before conception through the first trimester of pregnancy). Ensure that your folic acid supplement also contains vitamin B12. Follow the advice of your health care provider.
The evidence for neural tube defect risk reduction is for folic acid taken in a multivitamin supplement.
While higher intakes of fish during pregnancy and breastfeeding have been linked to better infant and child development, there is no evidence that women who follow a healthy diet and do not eat fish are at risk for pregnancy complications or poor child development.
Fish oil supplements that have a Natural Product Number (NPN) are safe to take for pregnant women. However, fish oil supplements should not be considered equivalent to eating fish.
Look for the NPN on the product label, which shows the fish oil supplement is government-approved for safety, efficacy, and quality. Health Canada has specific quality requirements for all natural health products, including fish oil supplements. The general quality requirements include testing for chemical impurities such as heavy metals, pesticides and known contaminants.
A daily intake lower than, or equal to, 3 grams of EPA plus DHA is considered safe by Health Canada. This amount has been studied in pregnant women without the occurrence of significant adverse effects.
The Institute of Medicine (IOM) in collaboration with Health Canada sets nutrient standards in the Dietary Reference Intakes. At this time, the IOM and Health Canada have not established a dietary recommendation for DHA. Note that dietary recommendations for DHA have been established by some other international organizations.