Does pregnancy affect the early response to cART?

OBJECTIVE

A part of women starting antiretroviral therapy during pregnancy fail to attain undetectable viral load by delivery. Here we studied whether pregnancy affects the early immunovirological response to combined antiretroviral therapy (cART), taking into account treatment duration and baseline characteristics.

DESIGN

Antiretroviral-naive women initiating cART since 2004 and followed in three French ANRS multicenter HIV cohorts (French Perinatal Cohort, PRIMO and COPANA).

METHODS

The early virological response (at 1, 3 and 6 months) and immunological increase after cART initiation were compared between women starting cART during (n = 708) and outside (n = 110) pregnancy. Relative risks were estimated in multivariate models adjusted for treatment duration, baseline viral load and CD4, sociodemographic factors and chronic hepatitis B. CD4 increases were compared by using mixed models.

RESULTS

Only 63.8% of treated pregnant women attained a viral load less than 50 copies/ml by delivery. Similarly to nonpregnant women, nearly 90% of pregnant women reached a viral load less than 400 copies/ml at M3 [adjusted RR: 1.0 (95% confidence interval 0.7-1.4)], and nearly 100% at M6 following cART initiation [0.9 (0.4-1.9)]. viral load less than 50 copies/ml was attained by 61.5% of pregnant versus 67.9% of nonpregnant women at M3 (P = 0.26), and by 82.1 versus 87.0% at M6 (P = 0.48). CD4 recovery (both number and percentage) was similar in pregnant and nonpregnant women. Results were similar for the subset of women starting a boosted protease inhibitor-containing cART.

CONCLUSION

Pregnancy does not affect the virological response to cART below 400 copies/ml, or CD4 increase. The main reason for pregnant women not achieving viral load less than 50 copies/ml at delivery appears to be a short duration of treatment.