A randomized trial evaluating a predominantly fetal growth-based strategy to guide management of gestational diabetes in Caucasian women

Abstract

Objective: To compare the management of Caucasian women with gestational diabetes (GDM) based predominantly on monthly fetal growth ultrasound examinations with an approach based solely on maternal glycemia.

Research design and methods: Women with GDM who attained fasting capillary glucose (FCG) <120 mg/dl and 2-h postprandial capillary glucose (2h-CG) <200 mg/dl after 1 week of diet were randomized to management based on maternal glycemia alone (standard) or glycemia plus ultrasound. In the standard group, insulin was initiated if FCG was repeatedly >90 mg/dl or 2h-CG was >120 mg/dl. In the ultrasound group, thresholds were 120 and 200 mg/dl, respectively, or a fetal abdominal circumference >75th percentile (AC>p75). Outcome criteria were rates of C-section, small-for-gestational-age (SGA) or large-for-gestational-age (LGA) infants, neonatal hypoglycemia (<40 mg/dl), and neonatal care admission.

Results: Maternal characteristics and fetal AC>p75 (36.0 vs. 38.4%) at entry did not differ between the standard (n = 100) and ultrasound groups (n = 99). Assignment to (30.0 vs. 40.4%) and mean duration of insulin treatment (8.3 vs. 8.1 weeks) did not differ between groups. In the ultrasound group, AC>p75 was the sole indication for insulin. The ultrasound-based strategy, as compared with the maternal glycemia-only strategy, resulted in a different treatment assignment in 34% of women. Rates of C-section (19.0 vs. 18.2%), LGA (10.0 vs. 12.1%), SGA (13.0 vs. 12.1%), hypoglycemia (16.0 vs. 17.0%), and admission (15.0 vs. 14.1%) did not differ significantly.

Conclusions: GDM management based on fetal growth combined with high glycemic criteria provides outcomes equivalent to management based on strict glycemic criteria alone. Inclusion of fetal growth might provide the opportunity to reduce glucose testing in low-risk pregnancies.