A history of prior preeclampsia as a risk factor for preterm birth

The objectives of this study are to evaluate the frequency and type of preterm birth (PTB) in women with prior preeclampsia and to compare neonatal outcomes between spontaneous PTB (SPTB) and medically indicated PTB (IPTB) groups.

A secondary analysis of data in women with prior preeclampsia enrolled in a multicenter randomized trial for preeclampsia prevention. Delivery indications were categorized as SPTB and IPTB. Primary outcomes were rates of SPTB and IPTB by gestational age (GA). The rates of composite respiratory morbidity and neonatal intensive care unit (NICU) admission were compared between the PTB groups.

Of the 606 pregnancies studied, 142 (23%) pregnancies were delivered at < 37 weeks: 67 (47%) pregnancies were caused by SPTB and 75 (53%) pregnancies were caused by IPTB. Of those who delivered preterm, 89 (63%) were in the late preterm period. The overall rate of the composite neonatal morbidity was 23%. The rates of composite neonatal morbidity, NICU admission, and perinatal death were not different between the groups. The frequency of small for gestational age (SGA) infants was higher in the IPTB group as compared with the SPTB group (21.3 vs. 1.4%, p = 0.01).

Women with prior preeclampsia are at high risk for PTB (SPTB and IPTB), particularly late PTB, as well as increased risk for SGA.