Does Maternal Body Mass Index Influence Treatment Effect in Women with Mild Gestational Diabetes?

Abstract

Objective To determine whether maternal body mass index (BMI) influences the beneficial effects of diabetes treatment in women with gestational diabetes (GDM). Study Design Secondary analysis of a multicenter randomized treatment trial of women with GDM. Outcomes of interest were elevated umbilical cord c-peptide levels (>90th percentile 1.77 ng/mL), LGA birth weight (>90th percentile), and neonatal fat mass (g). Women were grouped into five BMI categories adapted from the WHO International Classification of normal, overweight, and obese adults. Outcomes were analyzed according to treatment group assignment. Results A total of 958 women were enrolled (485 treated and 473 controls). Maternal BMI at enrollment was not related to umbilical cord c-peptide levels. However, treatment of women in the overweight, Class I, and Class II obese categories was associated with a reduction in both LGA birth weight and neonatal fat mass. Neither measure of excess fetal growth was reduced with treatment in normal weight (BMI <25) or Class III (BMI ≥ 40) obese women. Conclusion There was a beneficial effect of treatment on fetal growth in women with mild GDM who were overweight or Class I and II obese. These effects were not apparent for normal weight and very obese women.

Maternal overweight is not an independent risk factor for increased birth weight, leptin and insulin in newborns of gestational diabetic women: observations from the prospective ‘EaCH’ cohort study

“…Our observations are in line with data from other cohort studies showing that treatment of GDM, i.e., achieving good metabolic control, can significantly reduce the potential effects of maternal (prepregnancy) BMI status on adverse anthropometric perinatal outcomes [ 37 – 39 ]. Beyond their focus on LGA and macrosomia, the present study additionally highlights the influence of maternal 3rd trimester glycemia on a wide birth weight and relative birth weight range.…”

What we have learned about treating mild gestational diabetes mellitus

“…15 Results from another secondary analysis found that the treatment effect on fetal overgrowth varied by maternal body mass index (BMI), with treatment reductions in large for gestational and neonatal fat mass observed in women with a BMI between 25–39.9 kg/m 2 , but no benefit at the lowest and highest BMI extremes. 16 In the lowest BMI group, the frequency of fetal overgrowth was already low (approximately 2% in the untreated group), and the lack of a treatment benefit in the morbidly obese group may indicate a limit to improvements achievable through a GDM intervention directed toward maternal glucose levels alone. 16 …”

“…16 In the lowest BMI group, the frequency of fetal overgrowth was already low (approximately 2% in the untreated group), and the lack of a treatment benefit in the morbidly obese group may indicate a limit to improvements achievable through a GDM intervention directed toward maternal glucose levels alone. 16 …”

Antepartum Care of Women Who Are Obese During Pregnancy: Systematic Review of the Current Evidence

“…46 Similarly, Casey et al conducted a secondary analysis of 958 women with GDM enrolled in an RCT designed to explore the influence of BMI on outcomes such as neonatal birth weight and fat mass. 47 They found that formal nutritional counseling, diet therapy, daily self-monitoring of blood glucose, and insulin as needed, in women with BMIs of 40 kg/m 2 or more, did not improve outcomes of excess neonatal weight or fat mass, whereas these interventions did reduce the incidence of excessive neonatal weight in women with lower BMI ranges (25.00–39.99 kg/m 2 ). 47…”

“…47 They found that formal nutritional counseling, diet therapy, daily self-monitoring of blood glucose, and insulin as needed, in women with BMIs of 40 kg/m 2 or more, did not improve outcomes of excess neonatal weight or fat mass, whereas these interventions did reduce the incidence of excessive neonatal weight in women with lower BMI ranges (25.00–39.99 kg/m 2 ). 47…”