<prompt> Which of the following trigger onset of labour?ACTH in motherACTH in fetusProstaglandinOxytocin  <response>: Fetal ACTH acts on fetal adrenal gland causing release of DHEA and DHEA sulphate which are used by the placenta along with the other enzymes like Sulfatase ,Aromatase, 3 B hydroxysteroid dehydrogenase, 17 B hydroxysteroid dehydrogenase -Conveing into Estriol and Estardiol that help in triggering the labour. Ref: Williams Obs 24e pg 108-109. 