28 Mar 2025 • A recent analysis of over 8,000 pregnancies found that the optimal rate of weight change per week during each trimester varies by pre-pregnancy body mass index (BMI) and differed from than current recommendations of the National Academy of Medicine (NAM) guidelines.

For normal/underweight women, optimal weight gain of 0.7 kg/week in the first and second trimesters was linked to higher risks of preterm birth and small-for-gestational-age (SGA) births, compared to NAM’s recommendations.

Similarly, overweight women with a weight gain of 0.5 kg/week in the second trimester also faced higher risks of SGA when following NAM guidelines.

In contrast, obese women in the third trimester had a reduced risk of cesarean delivery when adhering to NAM guidelines.

The findings suggest that the current recommendations may be too restrictive. Adjusting weight gain recommendations based on BMI may help better manage pregnancy outcomes.

Source: AJOG | Read Full Story