Higher Rate of Mother-to-Child Transmission Among Women With Perinatal HIV

The rate of mother-to-child transmission (MTCT) of HIV is higher in women with perinatal HIV (PHIV) compared with mothers with horizontally acquired HIV, and PHIV is also associated with a greater likelihood of detectable viral load at delivery, according to a recently published study in The Pediatric Infectious Disease Journal.

Although the rate of MTCT of HIV in the United States has decreased dramatically since the advent of antiretroviral therapy, MTCT continues to occur. Therefore, understanding maternal obstetric factors associated with these cases can identify areas of focus for prevention efforts.  

A total of 2123 live-born infants delivered as of June 30th, 2015, from the Pediatric HIV/AIDS Cohort Study were included; 1666 (78%) were reported as uninfected, 448 (21%) had undetermined HIV-infection status, and 9 infants were infected with HIV.

The investigators calculated a rate of MTCT of 0.5% for those infants with a defined infection status. No differences in race or ethnicity were identified; however, the HIV-infected infants were more likely to be female. 

Characteristics between transmitting and nontransmitting mothers differed. The median age of transmitting mothers at delivery was 24.3 years while the median age of nontransmitting mothers at delivery was 28.5 years. Transmitting mothers were more likely to have their final viral load during pregnancy >1000 copies/mL (67% vs 11%, respectively), but the proportion with a final CD4 count <200 cells/mm³ was similar between the two groups (11% vs 9%).

A total of 232 (0.9%) of the 2123 mother-infant pairs included a mother with PHIV. The rate of MTCT was 1.1% (95% CI, 0.3-4.3) among mothers with PHIV and 0.4% (95% CI, 0.2-1.0) among those with horizontally acquired HIV. Mothers with PHIV were significantly more likely to have their final viral load during pregnancy >1000 copies/mL (P <.001) and their final CD4 count <200 cells/mm³ (P <.001).

Overall, the study authors conclude that “efforts to decrease rates of transmission should focus on viral suppression during pregnancy, and women with PHIV warrant particular attention.”

Reference 

Goodenough CJ, Patel K, Van Dyke RB. Is there a higher risk of mother-to-child transmission of HIV among pregnant women with perinatal HIV infection [published online May 4, 2018]? Ped Infect Dis J. doi: 10.1097/INF.0000000000002084