How much weight should I gain in pregnancy?
This depends largely on your weight at the beginning of pregnancy but as a general guide based on BMI the “target” weight gains (for a singleton pregnancy, no diabetes) are as follows
- Underweight (BMI <18.5) – 12.5-18kg
- Normal (BMI 18.5-24.9) – 11.5-16kg
- Overweight (BMI 25-29.9) – 7-11.5kg
- Obese (BMI >30) – 5-9kg)
Overall caloric intake only needs to increase by 10-25% as your pregnancy progresses (you’re never really eating for two!).
What makes up the weight gain in pregnancy?
- 40% of weight gain is baby and placenta
- 60% of weight gain is due to changes in the mother’s body (extra blood volume, fluid etc)
What impact can dietary intake and weight have on pregnancy?
- More calories in generally equates to higher weight gain (unless balanced by increased exercise)
- Higher maternal weight is associated with a higher risk of
- Gestational diabetes
- Babies who are large for gestational age or macrosomic
- Childhood obesity
- Poor nutrition and inadequate energy intake is associated with
- Low birth weight babies
- Increased risk of adult metabolic diseases such as type 2 diabetes in low birth weight babies
What about pregnancy supplements and vitamins?
There is good evidence for supplementing the following
- Folic acid to protect against neural tube defects (e.g. spina bifida)
- 0.5 mg daily for 3 months pre-pregnancy and for the first 3 months of pregnancy in the general population
- 5 mg daily for 3 months pre-pregnancy and for the first 3 months of pregnancy for women at higher risk (personal or family history)
- Iodine which is necessary for the developing brain and nervous system
- Calcium for women with calcium poor diets or who are at high risk for developing pre-eclampsia
There is currently limited evidence to support supplementation with
- Vitamins A, B6, B12, E, or D
- Iron in iron replete women
What sort of a diet should I adopt when pregnant?
A generally healthy and well balanced diet is recommended which includes
- Fruits and vegetables
- High quality carbohydrates
- Protein from lean meats, fish, beans
- Small amounts of sugar, red meat and processed foods
Where can I get more information?
You can always talk to your doctor about general recommendations. In some cases, specific dietary advice may be necessary from a qualified dietitian.
A good broad overview can be found at
Ref: Lowensohn, R et al. Current Concepts of Maternal Nutrition. Obstetrical and Gynecological Survey. 2016;71 (7):413-426