Expecting mothers who over-indulge and put on excessive weight early during pregnancy have an almost three times higher risk of delivering bigger and fatter babies according to a new University of Alberta study.

Study details

The research, published in the journal Obstetrics & Gynaecology, investigated weight gain patterns of 172 healthy pregnant women in Ontario, Canada, between 1995 and 2011.

In order to promote safe maternal weight gain, the participants were advised to stick to healthy eating guidelines and a simple exercise routine consisting of three to four weekly aerobic workouts.

The 2009 Institute for Medicine guidelines for pregnancy were used to categorise maternal weight gain as appropriate or early/late/overall excessive.

Study findings

A whopping 52% of the mothers involved gained excessive weight during their pregnancies. The scientists also found that participants who gained weight during the first half of pregnancy were 2.7 times more likely to deliver bigger babies who had an abnormally high body fat percentage (more than 14%).

The dangers of excess pregnancy weight gain:

For the baby

“Infants who are larger at birth tend to become larger children, and that creates a risk for developing into obese and overweight children and adults,” warned lead author and assistant professor Margie Davenport.

As you’re probably aware, compared to their leaner counterparts, overweight or obese individuals are at much higher risks of serious diseases like diabetes, cardiovascular diseases, certain cancers, renal failure and Alzheimer’s disease.

Previous studies have also linked excessive weight gain before and during pregnancy to increased foetal vulnerability to birth defects involving the neural tube (spina bifida), the heart and the abdominal wall.

For the mother-to-be

Gaining too much weight during pregnancy can predispose you to several complications such as gestational diabetes, pre-eclampsia and haemorrhoids.

Overweight or obese pregnant women are also more likely to go into preterm labour and/or to require emergency C-section.

What these findings mean for you

Planning to conceive? You may want to have your body weight and body composition checked — a dietitian can assist you. This will allow you to take the necessary dietary and fitness measures before baby is on the way.

Already pregnant? Do not attempt restrictive diets even if you’ve gain too much weight. Your best and safest option would be to meet a dietitian for tailored nutritional advice and for weight gain monitoring. Limiting your food intake without professional assistance could put you and your baby at risk of nutritional deficiencies.

Understand the ‘eating for two’ concept

“For many mothers, eating for two is taken too literally. People feel like they’ve been given an allowance to eat whatever they want, and that can lead to weight gain,” stated Sarah O’Hara, a registered dietitian who specialises in obstetrics.

Remember that the other one is a tiny foetus — while pregnancy increases a woman’s requirements for certain vitamins, minerals and essential fatty acids, there is no need for extra calories during the first two trimesters. You’ll only need an additional 200kcal during your third trimester.

“Expectant mothers need to be aware of pregnancy weight-gain guidelines and follow them to build a foundation for a healthy pregnancy and healthy baby. Healthy eating and physical activity when pregnant have long-lasting benefits to mother and child,” concluded Davenport.


    Davenport et al (2013) Timing of Excessive Pregnancy-Related Weight Gain and Offspring Adiposity at Birth. Obstetrics & Gynecology.

    Kaiser LL and Allen L (2008) Position of the American Dietetic Association: Nutrition and lifestyle for a healthy pregnancy outcome. J Am Diet Assoc. 108:553-61.

    Waller et al (2007) Pre-pregnancy Obesity as a Risk Factor for Structural Birth Defects. Arch Pediatr Adolesc Med. 161(8):745-50.