Women experience slight but significant increase in HIV viral load in 18 months after giving birth

HIV viral load rises slightly, but significantly in women in the 18 months after giving birth according to the results of a large US study published in the August 15^th edition of the Journal of Acquired Immune Deficiency Syndromes. The study also found that women who did not receive any form of anti-HIV therapy in the months after birth had a significantly increased risk of AIDS or death.

There are conflicting data on the risk of HIV disease progression in women in the months following delivery. Several small studies have found that women treated with AZT during pregnancy and delivery experience a rebound in their viral load in the months after giving birth. However, the US Pediatric AIDS Clinical Trials Group (PACTG) 076 study did not find any evidence of more rapid disease progression amongst women treated with AZT during pregnancy compared to those treated with a placebo.

Accordingly, investigators involved in the PACTG 185 study, which was primarily designed to see if taking immune modulators during pregnancy had any virological or immunological impact, analysed HIV viral load and CD4 cell count and response to anti-HIV therapy in 497 women with a CD4 cell count below 500 cells/mm³ in the 18 months after giving birth.

The study ran between October 1993 and March 1997, although there were significant advances in the treatment of HIV during this period, the study only included women treated during pregnancy with NRTI monotherapy or dual therapy, or women treated with a combination of NRTIs and NNRTIs. Women who were given protease inhibitors during pregnancy were excluded from the study, however, women could receive any HAART combination after giving birth. At baseline, women had a mean CD4 cell count of 312 cells/mm³ and a mean HIV viral load of approximately 8,000 copies/mL.

Patients were seen monthly during pregnancy, at delivery and then at weeks 12, 26, 48 and 78 when CD4 cell count and HIV viral load were measured.

The trial treatment was not found to have an impact on HIV disease progression after birth.

Regardless of the type of anti-HIV therapy received, HIV viral load declined during pregnancy, increased from delivery for the twelfth week for those on monotherapy or dual NRTI treatment, and then remained stable for the remainder of the study. Women starting HAART after delivery experienced a fall in their HIV viral load until the twelfth week after delivery, but then gradually increased. The investigators note, “overall, RNA levels increased modestly during the course of the study whether or not the subject received antiretroviral therapy; the increase was most significant for those on monotherapy or combination therapy [not HAART]” with HIV viral load increasing by approximately 0.2 log over twelve months.

In women taking NRTI monotherapy CD4 cell percentage was 23.5% at delivery and declined to 19.5% by month 18. Amongst women taking no antiretroviral therapy CD4 cell percentage was 22% at delivery and also fell to 19.5% at month 18. CD4 cell percentages were stable at approximately 24% in women who took HAART after delivery and a little under 23% in women taking dual therapy.

Compared to women who took no therapy, the investigators calculated that women who took AZT monotherapy had a hazard ratio (HR) of AIDS or death of 0.52 (95% CI, 0.25 – 104, p=0.06); the HR for women taking dual therapy was 0.17 (95% CI, 0.06 – 0.49, p=0.0009); and the HR for women taking HAART was 0.24 (95% CI, 0.06 – 1.01, p=0.051). Compared with receiving no anti-HIV therapy, taking monotherapy, dual therapy, or HAART was associated with a highly significant (p

Further information on this website

Anti-HIV therapy: options during pregnancy

Mother-to-baby transmission - factsheet