Many pregnant women reach the 38th, 39th or 40th week of pregnancy and start looking for any proven way to induce labor. Sex is often one of the first tactics many pregnant women will use to bring about the start of birth. Interestingly enough, though some doctors do not support the theory that sex induces labor, there is some proof that it may just be one of the safest and most effective method to bring on labor.
Semen injected into the vagina will inevitably hit the cervix. Semen contains prostaglandins which are known to soften the cervix. The softer the cervix, the easier the ripening and opening of the cervix will be. Thus, having unprotected intercourse with your partner may help to soften the cervix enough to aid in the inducement of labor.
Men and woman alike often have questions regarding the safety of sex during the latter stages of pregnancy. Sex is safe throughout pregnancy as long as it is comfortable for the pregnant woman; any pain or bleeding associated with sex should be reported to her physician.