My book reads,
"The fetus signals that it is mature by secreting certain hormones that diffuse across the placenta into mother's blood and cause the secretion of oxytocin from her posterior pituitary."
I would like to know what exactly are these hormones and their sites of production in the foetus, as well as their mode of action.
Also, I was wondering whether these hormones are released even during premature births? I doubt this because what I understand from the lines of my book is that it has to be a signal by the foetus that it is 'fully developed', whereas if it is not secreted it would not stimulate the secretion of oxytocin. This is creating a bit of confusion.
A detailed explanation would be a great help