18-07-2014, 05:18
It could be Estriol (E3) and Estetrol (E4) which are present during pregnancy. Estradiol (E2) has to be low during that time. Still its progesterone that increases prolactin.
https://en.wikipedia.org/wiki/Estriol
https://en.wikipedia.org/wiki/Estetrol
https://en.wikipedia.org/wiki/Estriol
https://en.wikipedia.org/wiki/Estetrol