Risk factors for emergent preterm delivery in women with placenta previa and ultrasound findings suspicious for placenta accreta.

AIM: To identify factors associated with emergent preterm delivery in women with placenta previa and suspected accreta.

METHODS: Pregnancies with placenta previa and ultrasound findings suspicious for accreta were identified. Demographic information and obstetric and neonatal outcomes were obtained from electronic medical records. Mann-Whitney U, Fisher's exact test, and Kaplan-Meier analysis were used. Continuous data are expressed as median (interquartile range).

RESULTS: Twenty-one patients with placenta previa and suspicion for accreta delivered at a median of 34 weeks [32-37]. Fourteen bled prior to delivery, 10 at <32 weeks. Fifty-seven percentage of deliveries were planned at a median gestational age of 36.5 weeks [34-37] vs. 32 weeks [29.5-32.5] for emergent deliveries (P<0.001). Emergent delivery was associated with transfusion of a median of nine units packed red blood cells (PRBCs) [4-16] compared to 4.5 units [1-7] with planned delivery (P=0.05).

CONCLUSION: Planned late perterm delivery is reasonable and likely women with placenta previa and ultrasound findings suspicious for placenta accreta who do not experience antepartum bleeding. Those women with multiple episodes of antepartum bleeding or bleeding prior to 32 weeks gestation are at increased risk of emergent preterm delivery.