Clinical assessment before starting PrEP
The risk of HIV transmission to women increases by over two-fold when they are pregnant (32). As reviewed recently, current evidence suggests that PrEP can be used safely during pregnancy and breastfeeding (33).
The use of TD*-containing regimens by HIV positive women throughout pregnancy has not been associated with adverse pregnancy outcomes, but lowered BMD has been observed in newborns exposed to TD* in utero (34, 35) as has a lower length and head circumference at 1 year of age (35).
In the Partners PrEP study, which compared the efficacy of TDF/FTC versus TDF versus placebo to reduce HIV transmission in African heterosexual HIV-serodifferent couples, 431 pregnancies occurred; the average duration of in utero PrEP exposure was 5 weeks. There was no difference in the incidence of pregnancy, birth outcomes or infant growth in women who received TDF or TDF/FTC versus placebo PrEP (36). However, as noted by the authors, the confidence intervals for these findings were wide and therefore definitive statements about the safety of TDF/FTC as PrEP during pregnancy could not be made based on this study’s findings. A subsequent study from this group examined the pregnancy outcomes of 30 women who continued to use PrEP during pregnancy compared to 96 pregnancies without PrEP exposure. The authors found that there was no increase in adverse pregnancy outcomes or restrictions in infant growth between the two groups (37). The World Health Organization has included PrEP as an HIV prevention strategy during pregnancy (38) and a number of other jurisdictions recommend PrEP for safe conception and for use during pregnancy and breastfeeding (39).
Some women with an HIV-positive partner may prefer to continue PrEP while pregnant, due to an increased risk of acquisition of HIV if their partner is not reliably virologically supressed during pregnancy (39). The lead in time for PrEP to reach highly effective levels in women is 7 days (40). A study evaluating antiretroviral excretion in breast milk and infant absorption suggests PrEP can be safely used during breastfeeding with minimal infant drug exposure (41). The ASHM PrEP Guidelines Panel will continue to monitor the safety of TD*/FTC PrEP regimens when used during pregnancy and breastfeeding.