Weight gain in pregnancy: not too much, not too little
A new study reveals cardiometabolic problems in children of mothers who have gained too much or too little weight during pregnancy.
New research published in Diabetologia shows that if a woman gains either too much or too little weight during pregnancy, there are adverse effects in children at seven years of age.
The study by Claudia H. T. Tam et al. evaluated the relationship between gestational weight gain (GWG) and cardiometabolic risk factors — such as high blood pressure and poor blood sugar control. Although there have been various studies on the effects of weight gain during pregnancy, data on the metabolic effects in the children subsequently born had not until now been studied comprehensively.
Tam et al. monitored a total of 905 mother–child pairs, who were enrolled in the multicentre ‘Hyperglycemia and Adverse Pregnancy Outcome’ study, at the study centre in Hong Kong. Women were classified as having gained weight below, within or exceeding the 2009 Institute of Medicine (IOM) guidelines. Also factored into the study were standardized GWG values based on pre-pregnancy body-mass index (BMI).
Among the 905 women, the mean pre-pregnancy BMI was 21 kg m−2; 8.3% of the participants were overweight and/or obese. The weight change from pre-pregnancy to delivery was 15 kg on average, with 17% having gained weight below, 42% having gained weight within, and 41% having gained weight exceeding the IOM recommendation.
Independent of pre-pregnancy BMI (and glucose level during pregnancy), women who gained more weight than the IOM recommendation had offspring with larger body size at age seven years and increased odds of higher body fat, high blood pressure and poor blood sugar control, compared with those who gained weight within the recommended range. Women who gained less weight than the IOM recommendation had offspring with increased risks of high blood pressure and poor blood sugar control at seven years of age.
The authors say, “These findings have important implications for both prevention and treatment. There is a need for greater awareness and monitoring of weight gain during pregnancy. Pregnancy might be a potential window of opportunity for intervention through modifiable behaviours, including maternal nutrition and physical activity.”
They also stress that, “Although limiting excessive GWG may help minimise the intergenerational cycle of obesity, the benefits of lower weight gain must be balanced against other cardiometabolic risks, such as high blood pressure and poorer blood sugar control, and risk of stunted growth in the offspring if GWG is inadequate.”
They conclude that long-term follow-up of these children is necessary to evaluate the effect of maternal GWG on cardiometabolic risk in adolescence and adulthood.
By: Ben Bishop/Diabetologia - Editorial Office