Objective: Our purpose was to investigate factors relevant to mode of delivery for patients with preterm (< 34 weeks) gestation complicated by the syndrome of hemolysis, elevated liver enzymes, and low platelets (HELLP).
Study design: The pregnancies of 189 patients with HELLP syndrome and delivery < 34 weeks' gestation between January 1980 and October 1991 were studied retrospectively. Only patients with class 1 (platelet nadir < or = 50,000 per microliter, n = 83) and class 2 (platelet nadir > 50,000 to < or = 100,000 per microliter, n = 106) HELLP syndrome were included. Maternal and perinatal factors relevant to type of delivery were reviewed.
Results: The incidence of cesarean delivery for all patients was 76.2% (primary rate 72.4%). Abdominal delivery occurred equally between class 1 (78.3%) and class 2 (74.5%) patients. Cesarean section was the mode of delivery for 87% of pregnancies at < 30 weeks' gestation in contrast to 68% of pregnancies at > or = 30 weeks but < 34 weeks' gestation (odds ratio 3.2, 95% confidence interval 1.4 to 7.5, p < 0.005). Indications for cesarean section included deteriorating maternal condition alone (50%), deteriorating maternal and fetal condition (27%), nonvertex fetal presentation (11.5%), and failure to progress (11%). Induction of labor was significantly more successful during the > or = 30 but < 34 weeks' pregnancy interval (47.5%) than in pregnancies at < 30 weeks (15.2%) (odds ratio 0.2, 95% confidence interval 0.1 to 0.55, p < 0.001). A trial of labor was successful in 22% of patients with an initial modified Bishop score < or = 2 versus 45% with an initial Bishop > 2 (odds ratio 0.5, 95% confidence interval 0.2 to 1.3, p = 0.16).
Conclusion: Parturients with class 1 and 2 HELLP syndrome at < 34 weeks' gestation are at high risk for cesarean delivery. At a gestational age < 30 weeks, the likelihood of successful labor induction with vaginal delivery is remote, especially in association with an unfavorable cervix or the absence of labor.