different placental locations during pregnancy. major and normal placenta previa, total and partial

anatomy baby birth birthday body child childbirth cord delivery development diagram embryo entanglement female fetal fetus foetus front gestation growth gynecology head human illustration infant locations marginal maternity medical medicine mother motherhood newborn normal obstetrics partial pelvic placenta placental praevia pregnancy pregnant prenatal presentation previa reproduction total ultrasound umbilical uterus vagina vector woman womb