Question

Which hormone's rising concentration promotes stronger uterine contractions near term?

Options

• Progesterone

• Oestrogen

• Relaxin

• Prolactin

Answer 1

As pregnancy progresses, rising oestrogen concentration promotes stronger uterine contractions near term. Oestrogen increases the number of oxytocin receptors on uterine muscles and raises the oestrogen: progesterone ratio, making the uterine muscles more sensitive to contraction signals.