Information about sexual activity, enjoyment and libido was obtained at intervals from 119 primiparous women during a longitudinal survey of maternal emotional health in pregnancy and for a year after delivery. Most subjects described some reduction in the frequency of sexual intercourse and a diminution of libido and sexual enjoyment during pregnancy; this was most marked in the third trimester. After delivery, about a third of subjects had resumed intercourse by six weeks and nearly everyone had done so by three months. Nevertheless, 77% and 57% of the women were having intercourse less often at three and 12 months after delivery respectively, in comparison with the month before they became pregnant. Selected variables were examined for relationship with a low, or reduced frequency of intercourse and with a lack of enjoyment. Significant associations were found with aspects of maternal personality and childhood relationships, marital conflict, maternal depression, previous miscarriages, difficulties in conceiving and fears of harming the fetus. Nausea and vomiting during pregnancy, the mode of delivery and related obstetric and medical variables, breast-feeding and characteristics of the baby, did not appear to significantly influence maternal sexuality.