Preconception and Weight
A woman’s weight status should be assessed prior to pregnancy to determine her body mass index (BMI). Her pre-conception BMI is used to determine proper weight gain goals during pregnancy.1 Women should be encouraged and supported to attain and maintain a pre-pregnancy BMI within the normal range to promote better health and decreased risk of disease in both herself and her infant.1
Women with a high BMI (>25) are at increased risk of poor health and poor pregnancy outcomes, such as increased risk of gestational diabetes, preeclampsia, labour complications and excess postpartum weight retention.2Their infants are at risk of fetal overgrowth (large-for-gestational-age infant), fetal distress, and childhood obesity.2 Women with a low BMI (<18.5) are also at increased risk of complications, including risk of pre-term delivery and birth of a small-for-gestational-age infant.2
Weight Gain during Pregnancy
Weight gain during pregnancy is used as a marker of health of the mother and the developing fetus. Weight gain goals are set based on a woman’s pre-pregnancy BMI and whether it is a multiple pregnancy.1 Weight gain can also be affected by factors, such as genetic characteristics, underlying health concerns, socioeconomic status and attitude towards weight gain.1 Generally, a woman will gain approximately 1 to 2 kg in the first trimester.1 Women who gain more or less should be assessed as they may be at risk of complications.1
The charts below list weight gain goals.