Early in pregnancy (less than 12 weeks), the changes in libido are diverse. Because of individual differences, sexual desire may increase or decrease. But, during the middle stages of pregnancy, libido generally increases, when most of the early discomforts are relieved -- aside from the larger stomach -- and the mother adjusts to being pregnant. The breasts still feel inflated but breast pain, mammaglia, is mostly alleviated. After about 19 weeks, preparations for breast-feeding are complete, and stimulation of the breasts may cause foremilk to be secreted. Because blood vessels inside the vagina become more abundant and cause the vagina to swell easily, a vaginal lubricant may be used if sex is awkward and uncomfortable.
After 20 weeks, as the top of the uterus reaches the belly button, the lower stomach begins to bulge out. The stomach grows quickly and the shape of the body changes. During intercourse, a position that doesn't put pressure on the stomach is recommended. At this time, mothers with a high risk of premature birth and mothers diagnosed with placenta previa must refrain from intercourse. Mothers with serious illnesses like gestosis should avoid orgasm because of the rise in blood pressure (systolic, a 30-80 mm Hg rise; diastolic, a 20-40 mm Hg rise). As the last month approaches, the top of the uterus reaches the precordium. The cervix descends and becomes soft enough that even light contact can cause bleeding. There is some disagreement over how long it is safe to continue having intercourse. Some scholars, fearing infection, argue that during the last 2 months a couple should practice abstinence, but others argue that as long as a condom is used, intercourse is fine. Generally, a large majority of couples control their sex lives as the last month approaches. Actually, intercourse and the uterine contractions that accompany orgasm do not induce labor or harm the baby. During the last month, the birth canal should be kept clean without infection, and one must consider the mother's physical discomfort. Spending this time wisely, with plenty of conversation, is advisable.