(1043) Increased risk of major fetal anomalies in cases of severe placenta accreta spectrum

Objective: To evaluate the incidence of congenital fetal anomaly in pregnancies with placenta accreta spectrum (PAS).

Study Design:

Study design: This is a prospective cohort study of PAS cases from January 2018 – July 2024. Consecutive patients with clinically and histopathologically confirmed PAS were included. Ultrasound assessments were performed by fetal-medicine specialists in a tertiary referral centre for PAS. 

Results:

Results: 73 participants with a mean age of 36.0±3.6 met inclusion criteria. In seven cases (9.5%), a major fetal congenital anomaly in a euploid fetus was diagnosed, compared to a background rate of 3%. The anomalies diagnosed were as follows: two major cardiac anomalies (hypoplastic left heart, right heart), two tracheoesophageal fistula, one severe ventriculomegaly, one giant omphalocele with hydrops, and one congenital diaphragmatic hernia. No case was associated with an underlying genetic diagnosis. In each case, clinical PAS findings were on the severe end of spectrum, with low implantation in early pregnancy which evolved to intraoperative topography consistent with type 2L (low lateral parametrial involvement) and 3 (low anterior cervical).

Conclusion:

Conclusion: Severe PAS may be associated with a higher rate of fetal congenital anomaly, which in our cohort were major single structural anomalies without genetic associations. PAS cases associated with congenital fetal anomalies were lateral and cervical defects on the severe end of the spectrum. These structural defects suggest fetal insult in early pregnancy from 5-9 weeks gestation. It is possible early implantation within a previous uterine scar results in vascular disruption of embryonic development and the subsequent development of structural fetal anomaly. These cases present significant clinical challenges and warrant specialist multi-disciplinary care to include neonatology and paediatric surgery to ensure safe delivery timing to optimise maternal health and fetal outcomes. PAS cases should have a detailed fetal medicine assessment in view of the higher incidence of fetal anomalies.