Use of fetal ultrasound to select metabolic therapy for pregnancies complicated by mild gestational diabetes.
OBJECTIVE
To determine whether fetal ultrasound early in the third trimester can identify Latina with mild gestational diabetes mellitus (GDM) whose fetuses are at risk for macrosomia and, if so, whether maternal insulin therapy can reduce that risk.


METHODS
Study subjects included 303 consecutive women with GDM and a fasting serum glucose level < 5.8 mM on diet therapy who had a fetal ultrasound between 29 and 33 weeks gestation. Of the women, 98 (32%) had a fetal AC > or = 75th percentile for gestational age, and 59 women completed a randomized trial of diet therapy (n = 29) or diet plus twice daily insulin (n = 30). Maternal nutrient levels were assessed by meal tolerance testing (MTT) before and during therapy and by capillary glucose monitoring four to seven times a day. Birth weights corrected for gestational age and neonatal glycemia and skin folds were the primary outcome variables compared between treatment groups.


RESULTS
Diet and diet-plus-insulin groups were well matched for maternal age, prepregnancy relative weight, weight gain during pregnancy, and glycemia at entry. Insulin therapy reduced maternal capillary (P < 0.005) and MTT (P < 0.001) glucose levels and prevented a diet-associated rise in MTT triglyceride levels (P < 0.002). Gestational age at delivery was similar in insulin- and diet-treated groups (39.6 +/- 0.2 vs. 39.5 +/- 0.2 weeks). Birth weights (3,647 +/- 67 vs. 3,878 +/- 84 g; P < 0.02), the prevalence of large-for-gestational age infants (13 vs. 45%, P < 0.02), and neonatal skin-fold measurements at three sites (P < 0.005) were reduced in the insulin-treated group. Rates of transient neonatal hypoglycemia were low in both treatment groups (14 and 18%, respectively) and did not differ significantly between groups.


CONCLUSIONS
Fetal ultrasound early in the third trimester identified women with mild GDM whose infants were at high risk for fetal macrosomia in the absence of standard glycemic criteria for insulin therapy. Insulin treatment reduced the macrosomia, indicating that fetal ultrasound can be used to guide metabolic therapy in pregnancies complicated by mild GDM.
Buchanan
T A
TA
Department of Medicine, Los Angeles County and University of Southern California Medical Center.
Kjos
S L
SL
Montoro
M N
MN
Wu
P Y
PY
Madrilejo
N G
NG
Gonzalez
M
M
Nunez
V
V
Pantoja
P M
PM
Xiang
A
A
D000704:Analysis of Variance; D001724:Birth Weight; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D016640:Diabetes, Gestational / Q000503:physiopathology / Q000628:therapy*; D003927:Diet, Diabetic; D004435:Eating; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007328:Insulin / Q000627:therapeutic use*; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D016216:Ultrasonography, Prenatal
D001786:Blood Glucose; D007328:Insulin