 According to the guidelines provided by the U.S. Institute of Medicine (IOM), normal-weight women should gain 11.5 to 16kg and obese women should gain 5 to 9 kg during pregnancy. The medical community has been debating over these guidelines for a very long time. But according to new research published in The Lancet journal, obese pregnant women don’t need to gain the recommended weight during pregnancy.Â
This research was conducted by the Karolinska Institute in Sweden and focused on obese pregnant women. Researchers used data from the Stockholm-Gotland Perinatal Cohort. They involved 15,760 obese women who had singleton pregnancies and delivered babies between Jan 1, 2008, and Dec 31, 2015. They tracked these women for 8 years after their deliveries. Â
Researchers classified these women into three classes based on their body mass index (BMI) such as obesity class 1, consisting of 11667 women with BMI of 30 to 34.9, obesity class 2, consisting of 3160 women with BMI of 35 to 39.9 and obesity class 3, consisting of 933 women with BMI over 40.Â
In this study, researchers examined 10 adverse outcomes that are linked to weight gain such as preterm birth, gestation diabetes and pre-eclampsia. The results showed that women in obesity classes 1 and 2 had no risk of adverse outcomes when they did not gain weight recommended by IMO guidelines. Â
When researchers observed obesity class 3 for adverse outcomes, they saw that women who did not gain weight and even lost weight during pregnancy had reduced the risk of adverse outcomes. The reduction of the risk of adverse outcomes was approximately 20% less.Â
The findings of this study showed that even if obese pregnant women don’t follow the weight gain guidelines given by IOM, there is no health risk for either the mother or the child. In fact, women in obesity class 3 showed that weight gain below the standards or even weight loss during pregnancy may be beneficial to reduce the risk of adverse outcomes.Â
The findings of this research show that there is a need to lower or remove the current IMO recommendation for obese pregnant women. This research will help healthcare professionals rethink the guidelines that we already have for weight gain during pregnancy so that they will make more informed and effective prenatal care plans. Â
Reference Link:Â
 Kari Johansson et al, Safety of low weight gain or weight loss in pregnancies with class 1, 2, and 3 obesity: a population-based cohort study, The Lancet (2024). Â
