The effects of pregnancy and childbirth on sexuality were studied in 50 women. Dyspareunia was more common in primiparae, but in other respects the same reactions and changes in behaviour were reported by multiparous and primiparous women. Coital frequency and orgasmic capacity decreased during pregnancy. The period of abstinence from coitus before and after delivery varied considerably. During pregnancy 72% of the women experienced a waning of sexual desire. Three months after childbirth 20% of the women still had little desire for and a further 21% had a complete loss of desire for or aversion to sexual activity. Sexual desire increased for a few women both during pregnancy as well as after childbirth. Pre-disposing factors in relation to diminished desire are discussed. The role of Maternity Clinic staff in providing information and advice is emphasized.