During the first trimester, the glands in the breasts that produce milk grow rapidly. Your body also releases prolactin, a pregnancy hormonethat promotes milk production, says patrick duff, md, associate dean of the obstetrics and gynÒ€¦ there's not much you can do to prevent your nipples from leaking during pregnancy, but you can help control an unexpected flow. Many people experience a tingling sensation that accompanies the initial release of milk.

Most of the time, this discharge is due to normal milk duct deveÒ€¦