Hi Karleen, There is a sensitive interplay between estrogen, progesterone, leutinizing hormone, follicle stimulating hormone that causes ovulation. High prolactin levels (or prolactin bursts from sucking in moms of older babies) inhibits these other hormones at the level of the hypothallamus and pituitary, which reduces stimulation of the ovary, which blocks ovulation. Without the same interplay of hormones, the endometrium does not build up beyond a certain level, so periods are not triggered. Ovulation seems to be more sensitive than endometrial changes to this suppression, therefore most women have one or more periods before ovulation resumes. There are many articles published on the specifics, I found many of them doing a medline search on metoclopramide and prolactin 10 years or so ago... -- Catherine Watson Genna, IBCLC New York City mailto:[log in to unmask] *********************************************** To temporarily stop your subscription: set lactnet nomail To start it again: set lactnet mail (or digest) To unsubscribe: unsubscribe lactnet All commands go to [log in to unmask] The LACTNET mailing list is powered by L-Soft's renowned LISTSERV(R) list management software together with L-Soft's LSMTP(TM) mailer for lightning fast mail delivery. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html