Question

Explain the various stages of parturition.

Answer 1

Parturition is childbirth at the end of gestation. Signals from the fully developed foetus and placenta initiate mild uterine contractions (the foetal ejection reflex), leading to oxytocin release. Oxytocin strengthens contractions, which in turn stimulate further oxytocin release. Prostaglandins also promote uterine contractions.

1. Dilation of the cervix: Rhythmic uterine contractions gradually widen the cervix. The amnion eventually ruptures and amniotic fluid flows out.
2. Expulsion of the baby: Strong contractions push the baby through the cervix and vagina, the birth canal. The newborn begins breathing.
3. Expulsion of the placenta: After the baby is born, the placenta and remaining umbilical cord are expelled.