Wanda is in labor. Which hormone is causing her uterus to contract for childbirth?

a. estrogen

b. prolactin

c. oxytocin

Oxytocin. It apparently kick starts labour and causes contractions.

I believe the correct answer from the choices listed above is option C. The hormone that is causing her uterus to contract for childbirth would be oxytocin. It is often known as the "hormone of love" because it is involved with lovemaking, fertility, contractions during labor and birth and the release of milk.