Prediction of the degree of abnormal invasive placentation by obstetric history.

Background: Diagnosis of placenta accrete spectrum (PAS) disorders is of utmost importance and mostly relies on high index of suspicion and sonographic criteria. The degree of abnormal invasive placentation is strongly associated with patients' outcomes. We aimed to determine the association between prior obstetric characteristics and the degree of PAS.

Methods: A retrospective cohort study. The study cohort comprised all women who delivered by cesarean delivery with a histopathological diagnosis of PAS during 2005-2019. We divided the cohort into 2 groups: severe PAS (increta/percreta) and mild PAS (accrete). Obstetrical characteristics and last delivery and cesarean characteristics were compared.

Results: Overall, 130 cases of histopathologically proven PAS were included. Of those 104 (80.0%) were mild PAS and 26 (20.0%) severe PAS. Both groups did not differ in terms of age and obstetric history. Mean parity of both study groups was 4. Intrapartum fever as noticed in 2.9-3.8% of primary cesarean (P=1.0). Cervical dilation at time of primary cesarean delivery was similar between the groups (mean 5 vs. 6 centimeters, P=0.73). Urgent cesarean delivery rate did not differ between groups (69.2% vs. 50.%, P=0.07). Method of hysterotomy closure was comparable as well. The only different variable found between groups was the rate of cephalic presentation at previous cesarean was higher in mild PAS group 69 (66.3%) vs. 11 (42.3%), P=0.024. odds ratio 2.68, 95% confidence interval 1.11-6.45.

Conclusions: Discrimination of PAS severity by obstetric and previous surgical history is questionable. Our findings might be limited by sample size. Future prospective studies are warranted.