Am J Obstet Gynecol. 1993 Sep;169(3):611-5.

Insulin-requiring diabetes in pregnancy: a randomized trial of active induction of labor and expectant management.
Kjos SL, Henry OA, Montoro M, Buchanan TA, Mestman JH.

Department of Obstetrics and Gynecology, University of Southern California School of Medicine, Los Angeles.

Objectives:

Our purpose was to assess whether a program of expectant management of uncomplicated pregnancies in mothers with insulin-requiring gestational or pregestational class B reduces the incidence of cesarean birth.

Study Design:

Two hundred women with uncomplicated, insulin-requiring diabetes at 38 weeks' gestation who were compliant with care and whose infants were judged appropriate for gestational age were randomly assigned to (1) active induction of labor within 5 days or (2) expectant management. The expectant management group was monitored with weekly physical examination and twice-weekly nonstress tests and amniotic fluid volume estimation until delivery.

Results:

Expectant management increased the gestational age at delivery by 1 week. Approximately half (49%) of the mothers in the expectant management group required induction of labor for obstetric indications. The cesarean delivery rate was not significantly different in the expectant management group (31%) from the active induction group (25%). The mean birth weight (3672 +/- 407 gm) and percentage large for gestational age, as defined by birth weight > or = 90th percentile, of infants in the expectantly managed group (23%) was greater than those in the active induction group (3466 +/- 372 gm, p < 0.0001, 10% large for gestational age). This difference persisted after controlling for gestational age and maternal age and body weight (p < 0.01).

Conclusion:

In women with uncomplicated insulin-requiring gestational or class B pregestational diabetes, expectant management of pregnancy after 38 weeks' gestation did not reduce the incidence of cesarean delivery. Moreover, there was an increased prevalence of large-for-gestational-age infants (23% vs 10%) and shoulder dystocia (3% vs 0%). Because of these risks, delivery should be contemplated at 38 weeks and, if not pursued, careful monitoring of fetal growth must be performed.