Reduction of Neonatal Macrosomia Rate of Infants Born to Overweight and Obese Women through Nutrition Counseling in Pregnancy - A One-arm Interventional Study.

Introduction: Because of fetal programming, neonatal macrosomia is associated with a higher long-term risk of metabolic disease. In 2020, the overall macrosomia rate of term-born singletons born to overweight or obese mothers in our center was approximately 30%. The aim of our study was to reduce the macrosomia rate with pregnancy-related nutrition counseling.

Methods: This is a single center, one-arm, interventional pilot study of 99 singleton pregnancies. The intervention took the form of three individual and group education sessions on pregnancy-relevant nutritional topics and exercise in the 10th to 14th, 20th to 24th and 30th to 34th weeks of gestation. The primary endpoint was the overall macrosomia rate born to overweight/obese mothers and birth ≥ 37 weeks of gestation. Macrosomia was defined as the presence of at least one of the following criteria: birth weight ≥ 4000 g, birth weight > 90th percentile, length-related birth weight > 90th percentile, birth weight > 90th percentile after adjustment for initial maternal weight and height. The results were compared with those of a non-interventional cohort from the same center.

Results: Ninety-one percent of pregnant women with a pre-pregnancy BMI ≥ 25 kg/m ² had a delivery at term (n = 77/85). The overall macrosomia rate of these children was 19.5% (95% CI: 11.3% to 30.1%, n = 15/77) and therefore lower than the expected BMI-corrected macrosomia rate of the comparison group of 31.3% (p = 0.026). In the total cohort, which included normal-weight women, a trend toward normalization of birth weights was observed (p = 0.083).

Conclusion: Professional nutrition counseling during pregnancy can reduce the neonatal macrosomia rate of infants born to women with a BMI ≥ 25 kg/m ² . Relevant provision of counseling services in the context of antenatal care would be useful for affected women.