Resistance

Some strategies to reduce mother-to-child transmission can lead easily to resistance. Using only 1 drug (monotherapy) or 2 drugs (dual therapy) is not as good as 3+ drugs (combination therapy).

Of monotherapy and dual therapy strategies, AZT used alone is less likely to lead to resistance than nevirapine alone or AZT + 3TC.

Resistance can also develop on combination therapy when a person’s viral load is over 50 copies/mL.

It is also possible to transmit resistant virus. The outlook for a baby born with resistant HIV is very poor. Their HIV will be much harder to treat.

Section 3: Resistance

Adherence

It is easy for a mother to forget her own health after the baby is born. For mothers taking HIV treatment, adherence is critical.

Missing dose, or taking them late, increases the chance of resistance.

• Many women have excellent adherence when pregnant, but find this hard after the baby is born.
• Many mothers find the best way to remember to take their own ARVs is to link this to when they give the new baby his or her treatment.

Section 3: Adherence – and why it is so important