Although no formal safety studies have been carried out, animal studies and a review of over 700 human births in which the infant was exposed to nelfinavir (Viracept) in the womb have found no increased risk of birth defects^[1]. This suggests that pregnant women may take nelfinavir without risking harm to the foetus, although they may experience higher rates of gastrointestinal side-effects and raised blood sugar levels than non-pregnant women^[2].

However, recent studies have shown that plasma concentrations of nelfinavir are reduced in pregnant women, although levels of the drug's active metabolite M8 may be unaffected^[3][4]. Plasma concentrations of the drug should be monitored where possible, and pregnant women should consider increasing the dose of nelfinavir to 1500mg twice a day^[5]. A double dose on the day of delivery may also be necessary to ensure adequate drug levels^[6].