Outcomes of Subsequent Births After Placenta Accreta Spectrum

To investigate subsequent birth rates, maternal and neonatal outcomes for women with a history of placenta accreta spectrum (placenta accreta, increta, and percreta).

A population-based record linkage study of women who had a first, second, or third birth in New South Wales from 2003 to 2016 was conducted. Data were obtained from birth and hospital records and death registrations. Women with a history of placenta accreta spectrum were matched to women without, on propensity score and parity, to compare outcomes with women who had similar risk profiles. Modified Poisson regression models were used to calculate adjusted relative risk (aRR) for a range of maternal and neonatal outcomes.

We identified recurrent placenta accreta spectrum in 27/570 (4.7%, 95% CI 3.0-6.5%) of second and 9/119 (7.6%, 95% CI 2.8-12.3%) of third pregnancies after placenta accreta spectrum in the preceding birth, with an overall recurrence rate of 38/689 (5.5%, 95% CI 3.9-7.5%, compared with the population prevalence of 25.5/10,000 births (95% CI 24.6-26.4). Subsequent births after placenta accreta spectrum had higher risk of postpartum hemorrhage (aRR 1.51, 95% CI 1.19-1.92), transfusion (aRR 2.13, 95% CI 1.17-3.90), cesarean delivery (aRR 1.19, 95% CI 1.02-1.37), manual removal of placenta (aRR 6.92, 95% CI 3.81-12.55), and preterm birth (aRR 1.43, 95% CI 1.03-1.98), with lower risk of small for gestational age (aRR 0.64, 95% CI 0.43-0.96), compared with similar-risk births.

Women with a history of placenta accreta spectrum have increased risk of maternal morbidity, preterm birth, and placenta accreta spectrum in the subsequent pregnancy compared with similar-risk women with no previous placenta accreta spectrum, although the absolute risks are generally low. These findings may be used to inform counseling of women on the risks of future pregnancies.