Delivery Timing of Placenta Accreta Spectrum: Later is Feasible.

Abstract

Background: Delivery at 34 0/7 - 35 6/7 weeks is recommended for patients with prenatally suspected placenta accreta spectrum (PAS); however, there is limited data to support these recommendations. As a large volume tertiary care center, in an otherwise uncomplicated pregnancy with prenatal concern for PAS, we have historically planned delivery at 36 0/7 - 37 6/7 weeks.

Objectives: To describe the impact of our later delivery timing in cases of suspected PAS on maternal and fetal outcomes.

Study design: We examined pregnancies ≥ 24w0d gestation complicated by prenatally suspected PAS from August 2009 to April 2022. Maternal and neonatal outcomes were compared according to delivery timing (beyond 36 0/7 weeks versus prior to this gestational age). Indication for early delivery was also extracted. Statistical analysis included χ² for categorical variables and student's t-test for continuous variables.

Results: Of 202 patients with prenatal concern for PAS, 65 (32%) had an early indication for delivery (bleeding, preeclampsia, premature rupture of membranes or labor) whereas 137 (68%) were planned deliveries beyond 36 0/7 weeks for concern for PAS. There was no difference in maternal age, race/ethnicity, parity, BMI, or number of prior cesarean deliveries. Median gestational age at delivery in the indicated group was 35 (31-36) weeks, versus 37 (36-37) weeks for those without complications (p< 0.001). Prenatally suspected severity of PAS did not differ between the groups, nor on pathology. Of patients delivered for an indication 42 (65%) were delivered for bleeding, 11 (17%) for labor, and 12 (18%) for other indications. The only maternal outcomes of noted difference between the groups was increased whole blood transfusions (more commonly used at our institution in emergent situations) in those with indicated deliveries (0 [0-6] vs 0 [0-4], p=0.007) and decreased platelet transfusions (0 [0-6] vs 0 [0-10], p=0.021). Neonates in the indicated cohort were more likely to have lower birthweights, neonatal intensive care unit admission, respiratory distress syndrome, need for mechanical ventilation, and longer hospital stays, all likely secondary to prematurity.

Conclusion: Patients with suspected placenta accreta spectrum without other indications for delivery such as bleeding, labor, rupture of membranes, or preeclampsia can have a planned delivery in the late preterm or early term period at specialized centers that are geographically in close proximity to the patient. Later delivery does not impact maternal outcomes and improves neonatal outcomes.