retroplacent alfibromyoma, previous PA, uterine malformation, previous cesarean section, chorioamnionitis,
premature rupture of the membranes (PROM), intrauterine infection, preeclampsia, Black race/ethnicity, diabetes mellitus,
a multiple fetus pregnancy, polyhydramnios, major fetal congenital abnormalities, male fetal gender, severe maternal stress,short or long sleep duration, low socioeconomic status, and elevated maternal serum alpha-fetoprotein levels during the second trimester. Women who have had PA have a 5–22% risk of recurrence in subsequent pregnancies; women whhave had PA twice have a 25% incidence of PA recurrence. Sisters of women with severe PA are at increased risk of developing the condition. Risk of developing DIC is greater in patients with concealed PA.