Diabetes Care, Vol 10, Issue 5 594-599, Copyright © 1987 by American Diabetes Association
Macrosomia in pregnancy complicated by insulin-dependent diabetes mellitus
M Small, A Cameron, CB Lunan and AC MacCuish
Diabetic/Obstetric Clinic, Royal Maternity Hospital, Glasgow, Scotland.
We assessed the factors influencing the birth weight of infants born to 83
women with insulin-dependent diabetes mellitus (IDDM) over a 5-yr period.
Maternal glycosylated hemoglobin (HbA1) concentrations at delivery
correlated with the percentile birth-weight ratios (r = .43, P less than
.001) and indicated that approximately 18% of variance in the birth weight
could be ascribed to glycemic control in the third trimester. Fetal
macrosomia occurred in 22 (27%) pregnancies. When 20 of these pregnancies
were compared closely with 20 nonmacrosomic pregnancies in diabetic women,
the mothers of macrosomic infants were found to be more obese, have a
history of previous macrosomic birth, and have higher concentrations of
serum human placental lactogen and urinary estriols in the third trimester.
Macrosomic pregnancy was further distinguished by accelerated fetal growth
(judged by serial ultrasonography) from the 32nd wk of gestation and by
biochemical (but asymptomatic) hypoglycemia in the neonate. In our study,
no serious neonatal morbidity could be attributed to macrosomic pregnancy.
Good glycemic control was attained in both groups, and no significant
differences between the groups in overall glycemic control throughout
pregnancy were noted. Thus, despite good glycemic control, macrosomia
remains comparatively common in modern pregnancy complicated by IDDM, and
factors other than maternal hyperglycemia must contribute to its etiology.