Data collection
The basic information on the pregnant women was collected, including
age, the times of pregnant, delivery times (≥ 28 weeks of delivery), the
numbers of former caesarean, the inter-birth interval between the
previous and the current caesarean section, the duration of gestation,
the thickness of the uterine scar, the type of placenta previa under
ultrasound (marginal, partial or complete at the front wall of the
uterus) and the condition of placenta attachment (adhesion, implantation
or penetration).
The data for perinatal outcomes of mother and newborn were also
collected, including the termination time of the pregnancy, whether
arterial blocking was applied and the related method, postpartum
hemorrhage, the volume of bleeding during the delivery, blood
transfusion, hysterectomy, uterine rupture, the intraoperative situation
of the placenta, infection, admission to an intensive care unit,
intraoperative hemostatic operations and the medicine used, the fetal
biparietal diameter before delivery, and Apgar score at 1min and 5min
after birth of newborns.