Studies have found that sexual intercourse during the last few weeks of pregnancy can help soften the cervix in preparation for labour.
Breast and nipple stimulation can also produce a strongly contracting womb and is sometimes encouraged to restart a labour that has stalled.
Clitoral stimulation is cited as an effective method of pain relief during labour. While the hospital delivery room may not be the most practical place to trial this method, it can be useful at home in the early stages of labour.
Nipple stimulation is also known to enhance the ability to breastfeed both in milk production and particularly for women with inverted nipples.
Semen
Some women are sensitive to the prostaglandins in semen. Prostaglandins are fatty acids made naturally in the body and are found in semen in a higher proportion than anywhere else in the human body. Women secrete prostaglandins during the latter stages of pregnancy both to soften the connective tissue of the cervix and increase oxytocin production in the muscle cells of the womb in preparation for labour. Synthetic prostaglandin gel is often used to soften the cervix and womb to induce labour. Many medical professionals recommend sex during the last few weeks of pregnancy for these reasons.