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

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