Induction of labor in pregnancies with suspected large-for-gestational-age fetuses and unfavorable cervix

Objectives: To evaluate our single-center, single-team experience with induction of labor in pregnancies with suspected large for gestational age (LGA) fetuses. Study design: A retrospective case-controlled design was used. Non-diabetic patients with a suspected LGA fetus (estimated fetal weight ≥90th percentile) (group 1, n=135) were compared with healthy patients admitted for elective induction of labor for either post-date pregnancy or a subjective perception of decreased fetal movements in the presence of normal fetal heart monitoring and biophysical profile (group 2, n=326), and with healthy women with normal pregnancies and spontaneous onset of labor (group 3, n=574). Results: There were no between-group differences in maternal age, parity, number of prostaglandin E2 (PGE2) tablets used, instrumental delivery rate or Apgar scores. The rate of cesarean section (CS) was significantly higher in the study group (33.3%) than in group 2 (17.8%, P=0.001) and group 3 (10.6%, P=0.004), although this difference disappeared when the multiparous women were analyzed separately (study group: n=58, 10.3% versus group 2: n=169, 7.7% and group 3: n=308, 7.8%, P=0.6). A logistic regression model (R ² =0.385, P<0.001) was used to control for maternal and gestational age, nulliparity rate, number of PGE2 tablets used, birth weight, and diagnosis (group 1 versus group 2) as predictors of mode of delivery. On stepwise (forward-likelihood) analysis, only nulliparity (odds ratio (OR) 10.0, 95% confidence interval (CI) 2.8-35.6, P<0.001) and maternal age (OR 1.2, 95% CI 1.06-1.36, P=0.002) were independently and significantly associated with increased risk of CS. Conclusions: Induction of labor for suspected LGA fetuses, if performed at all, should be reserved for multiparous women.