Obese women don’t need to put on extra kilos during pregnancy, study

The guidelines for weight gain during pregnancy in obese women have long been questioned.


Obese women don’t need to put on extra kilos during pregnancy, study

For obese women, gaining weight during pregnancy is a significant cause for concern. The severity of obesity should determine how different the recommendations are for women who are obese, as the current recommendations are excessively high.

In a recent collaborative study, the safety of losing weight or gestational weight gain below current recommendations in obese pregnancies was examined, and the necessity of developing different criteria for various obesity classes was assessed.

The Karolinska Institutet study supports lowering or doing away with the minimum 5-kg weight increase requirement.

The US Institute of Medicine (IOM) states that pregnant obese women ought to gain 5 to 9 kg, whereas normal-weight women should gain 11.5 to 16 kg. Although there have long been doubts about those guidelines, more data are needed to support a reanalysis.

According to this recent study, weight gain below the existing criteria for women with obesity class 1 and class 2 (BMI of 30–34.9 and 35–39.9, respectively) does not raise the mother’s or the child’s health risks. Conversely, weight gain that is below current recommendations may even be advantageous for women who have class 3 obesity (BMI > 40).

The study supports previous calls to either lower or remove the current recommended lower limit of a weight gain of at least 5 kg, according to Kari Johansson, a docent at the Department of Medicine, Solna.

Scientists hope that their study could inform a re-examination of national and international guidelines on weight gain during pregnancy.

Researchers carried out this study using registry data and electronic medical records for 15,760 obese women in Stockholm and Gotland (also known as the Stockholm Gotland Perinatal Cohort). In the study, 1,667 women had obesity class 1, 3,160 had class 2, and 933 had class 3. Pregnancies for singletons delivered between 2008 and 2015 were included in the study. Following delivery, the women were monitored for a median of eight years.

Pre-eclampsia, gestational diabetes, excessive postpartum weight retention, maternal cardiometabolic disease, unplanned cesarean delivery, preterm birth, large for gestational age and small for gestational age at birth, stillbirth, and infant death are the ten known adverse outcomes associated with weight gain during pregnancy that were examined. These negative consequences were grouped into an undesirable composite outcome and weighed based on severity.

Overall, the research indicates that among women in obesity classes 1 and 2, there is no increased risk of the undesirable composite outcome for weight gain below current IOM limits. Conversely, weight loss or weight gain below recommended levels was linked to a lower chance of the unfavorable composite outcome for women in obesity class 3. For instance, a risk decrease of almost 20% was related to the absence of weight gain or 0 kg.

Scientists concluded that “weight gain below current recommendations is likely safe in pregnancies with obesity, and might even be beneficial for those with class 3 obesity.”

Kari Johansson, a docent at the Department of Medicine, Solna, said“Unlike today, this group could receive separate recommendations.”

The researchers will now proceed with similar studies on overweight, normal-weight, and underweight women.

Journal Reference:

  1. Kari Johansson, Lisa M Bodnar, Olof Stephansson, Barbara Abrams, Jennifer A Hutcheon. “Safety of low weight gain or weight loss in pregnancies with class 1, 2, and 3 obesity: a population-based cohort study. The Lancet. DOI: 10.1016/ S0140-6736(24)00255-1
Latest Updates