Spontaneous version after preterm prelabor rupture of membranes.

BACKGROUND

Preterm prelabor rupture of membranes (PPROM), defined as rupture of membranes before the onset of labor at < 37 weeks' gestation, affects approximately 3% of all pregnancies. For PPROM prior to 34 weeks' gestation, in the absence of contraindications to expectant management, antibiotics are administered to increase the latency period and reduce the incidence of maternal and neonatal infection. The latency period additionally provides an opportunity for fetal presentation to change, which impacts the mode of delivery. It is important to better understand the incidence of spontaneous version after PPROM to enhance patient counseling with regard to the mode of delivery.

OBJECTIVE

To determine the incidence of discordant fetal presentation, resulting from spontaneous version, between admission for PPROM and time of delivery for cephalic and non-cephalic fetuses among patients diagnosed with PPROM prior to 34 weeks' gestation and to compare characteristics of those with and without discordant fetal presentation.

STUDY DESIGN

We performed a retrospective cohort study of singleton pregnancies diagnosed with PPROM identified using ICD-9/10-CM codes, < 34 weeks' gestation, admitted to a tertiary care center's antepartum service from 2011-2018. Patients were included if the fetal presentation was documented by ultrasound within 48 h of admission and PPROM, and delivery occurred >24 h after PPROM. Data are presented as proportions, median (interquartile range) or risk ratio and 95% confidence interval.

RESULTS

We included 209 patients. Patient age, body mass index, parity, and race/ethnicity were similar among patients with cephalic and non-cephalic fetal presentations at admission. Patients with cephalic presentation at time of PPROM presented at a later gestational age than patients with a non-cephalic presentation. Among patients with a cephalic presentation at admission, the incidence of non-cephalic presentation at delivery was 11.7% (19/162), whereas with non-cephalic presentation at admission, the incidence of cephalic presentation at delivery was 21.3% (10/47). While there was an increased risk of spontaneous version resulting in a discordant presentation at delivery with non-cephalic presentation, this relationship was attenuated and not significant when adjusted for gestational age at time of PPROM.​ Patients with discordant presentation presented with PPROM at an earlier gestational age and had a longer latency period compared to patients with a concordant presentation. Patient age, body mass index, amniotic fluid assessment at admission, and infant birth weight were similar in those with and without a change in fetal presentation.

CONCLUSION

Discordant fetal presentation resulting from spontaneous version from cephalic to non-cephalic presentation after PPROM occurred in 11.7% (19/162) of patients, while discordant presentation from non-cephalic to cephalic presentation occurred in 21.3% (10/47) of patients. Given the limited published data on spontaneous version after PPROM these results may impact patient counseling.