For many people living with HIV the availability of antiretroviral therapy means that they can hope for longer, healthier lives than was anticipated even fairly recently. One of the results in this difference for positive women (who have access to treatment) can mean that the possibility of having children may seem more realistic than in previous years. There are many HIV-positive women who are mothers whether diagnosed before or after their children were born and the prevalence of HIV infection amongst women giving birth in the UK has risen every year since 1990.

One of the difficulties for positive women who might decide to become pregnant is that there is a risk of vertical transmission (i.e. mother-to-child) of HIV. This risk is currently calculated in the UK as a one in seven chance that the baby will be infected if no preventativemeasures are taken. However, it is now known that highly effective preventative measures can reduce the risk of transmission.

In summary these preventative measures are:

• Treatment of mother and child with antiretroviral therapy.
• Delivery of the baby via a planned caesarean section (although there is increasing evidence suggesting that if a positive mother’s viral load is undetectable caesarean section may not be more beneficial than vaginal delivery).
• Feeding the baby exclusively with formula milk (i.e. avoiding breastfeeding).

These measures are discussed more fully in the Transmission Section.

It is also known that the risk of vertical transmission in women who have not been treated with ART is related to the health of the mother in relation to viral load, CD4 count and clinical disease stage. It is also related to obstetric factors such as length of labour and premature delivery: delivery before 34 weeks has been shown to increase the risk of vertical transmission.

However, although it is also the case that most babies born to positive women will be HIV–negative the interventions offered to reduce the risk of vertical transmission are not without side-effects and do not offer 100% protection.

The long-term effects of anti-HIV drugs on an HIV–negative child are not known, and Caesarean section is also not without danger for the mother. These risks must be balanced against the proven effectiveness of anti-HIV therapy in reducing transmission, and the well-established health consequences of being born HIV-positive.