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The following is a summary of “Emergency delivery in pregnancies at high probability of placenta accreta spectrum on prenatal imaging: a systematic review and meta-analysis,” published in the July 2024 issue of Obstetrics and Gynecology by Lucidi et al.

The study aimed to investigate the incidence of emergency cesarean section (CS) in pregnancies with a high probability of placenta accreta spectrum (PAS) disorders, as detected through prenatal imaging, and to compare the maternal and neonatal outcomes between patients requiring emergency CS and those undergoing planned elective CS. This single-center, retrospective cohort study included 7,587 women with positive first serum β-hCG levels following fresh and frozen embryo transfers from January 2011 to December 2020. Eligible women were aged 18 to 45 years, with serum β-hCG levels greater than 20 IU/L, and excluded cycles involving gamete donation, preimplantation genetic testing (PGT), or the transfer of more than three embryos simultaneously.

Data was sourced from Medline, Embase, Cochrane, and ClinicalTrials.gov databases. The study focused on case-control studies reporting outcomes of pregnancies with high PAS probability confirmed at birth. Variables analyzed included maternal and paternal age, previous abortions, number of embryos transferred, and primary indications for treatment. The main outcomes measured were emergency CS incidence, placenta accreta and increta/percreta incidence, preterm birth before 34 weeks of gestation, estimated blood loss (EBL), number of packed red blood cells (PRBC) units transfused, and various maternal and neonatal complications.

Among 1,290 pregnancies complicated by PAS, emergency CS was performed in 36.2% (95% CI 28.1-44.9), with 80.3% (95% CI 36.5-100) occurring before 34 weeks of gestation. Antepartum bleeding was the primary indication for emergency CS in 61.8% (95% CI 32.1-87.4) of cases. Patients undergoing emergency CS had significantly higher EBL (pooled mean difference [MD] 595 ml, 95% CI 116.1-1073.9, p<0.001), PRBC transfusions (pooled MD 2.3 units, 95% CI 0.99-3.6, p<0.001), and other blood products (pooled MD 3.0, 95% CI 1.1-4.9, p=0.002) compared to those with scheduled CS. Additionally, emergency CS was associated with higher risks of transfusion of more than 4 PRBC units (odds ratio [OR] 3.8, 95% CI 1.7-4.9, p=0.002), bladder injury (OR 2.1, 95% CI 1.1-4.00, p=0.003), disseminated intravascular coagulation (DIC; OR 6.1, 95% CI 3.1-13.1, p<0.001), and intensive care unit (ICU) admission (OR 2.1, 95% CI 1.4-3.3, p<0.001).

Neonates delivered via emergency CS had a higher risk of adverse composite outcomes (OR 2.6, 95% CI 1.4-4.7, p=0.019), NICU admission (OR 2.5, 95% CI 1.1-5.6, p=0.029), low Apgar scores (<7 at 5 minutes; OR 2.7, 95% CI 1.5-4.9, p=0.002), and fetal or neonatal loss (OR 8.2, 95% CI 2.5-27.4, p<0.001).

In conclusion, emergency CS complicates approximately 35% of pregnancies with PAS disorders and is associated with significant risks for adverse maternal and neonatal outcomes. Future large-scale prospective studies are essential to identify clinical and imaging indicators that can predict the necessity of emergency CS, intrapartum hemorrhage, and peripartum hysterectomy in patients with high PAS probability.

Source: sciencedirect.com/science/article/abs/pii/S2589933324001587