(653) Timing of antenatal placenta accreta spectrum diagnosis and impact on clinical outcomes: a multicenter study

We sought to assess the impact of timing of antenatal diagnosis on management and outcomes in patients with placenta accreta spectrum (PAS).

Study Design:

This was a multicenter historic cohort of all patients ≥ 23 weeks with antenatal suspicion and histopathological confirmation of PAS at four tertiary care institutions from 1/2013 - 6/2022. Gravidas with suspected PAS on ultrasound at 20 weeks or less (early diagnosis) were compared to those diagnosed after 20 weeks (late diagnosis). Primary outcome was planned delivery by multidisciplinary specialists’ team. Secondary outcomes were hemorrhage at delivery (defined as estimated blood loss > 1,500L) and massive transfusion (defined as transfusion of 4+ units of packed red blood cells). Chi-square and Fisher’s exact test were used as well as a multivariable logistic regression analysis.

Results:

401 cases of histopathologically confirmed PAS were identified during the study period. Of them, 222 (55.36%) were diagnosed antenatally: 65 (29.3%) had early diagnosis and 157 (70.7%) late diagnosis, with mean gestational age at diagnosis of 24.8 weeks. Overall, 180 (44.9%) gravidas had ultrasound for placental assessment in the first trimester and 371 (92.5%) in the second or third trimester. PAS detection rate improved from 13/180 patients (7.2%) in first trimester to 131/341 (38.4%) in second trimester (p < 0.01). Pregnancy by assisted reproductive technology (ART) was the only predictor of early antenatal diagnosis (aOR 4.24, 95% CI 1.08-16.67, p=0.03). Delivery was planned in 71.2% of patients with prenatal PAS diagnosis. Patients with early prenatal diagnosis had similar rates of planned delivery (63.1% vs 73.5%, p=0.08), hemorrhage (70.8% vs 58.6%, p=0.08) and massive transfusion (46.2% vs 38.2%, p=0.2), compared to those diagnosed after 20 weeks.

Conclusion:

In this historic cohort, most patients with antenatal diagnosis of PAS were diagnosed after 20 weeks. Approximately two thirds of patients with a prenatal PAS diagnosis had a planned delivery; diagnosis before 20 weeks did not appear to affect rates of planned delivery or adverse maternal outcomes.