Although the overall incidence of HIV infection in Britain seems much lower than originally predicted, the virus is undoubtedly established in the general community. There is also no doubt that growth in prevalence is now linked directly to heterosexual transmission.1 Inevitably then, family doctors and paediatricians will see an increasing number of cases of childhood AIDS in the coming years.

Despite the risks, couples with a partner known to be infected with HIV still opt for pregnancy. If the mother is infected her baby has a 15% chance of infection; the risk of vertical transmission is higher in developing countries.2 The desire for a child despite all the problems associated with HIV infection is now so common in families with haemophilia that it has long since ceased to be remarkable. Couples brave enough to discuss intended conception with their doctors are advised to have unprotected intercourse only at the time of ovulation, measured either with a prediction test or by natural family planning techniques. At all other times abstention or protected sex is suggested to lessen fetal risk from infected semen. The size of this risk is unknown, but Semprini and colleagues have now …