HIV rebound detected within 1 day before delivery in 50% of study participants.
Six percent of previously suppressed HIV-positive women experienced a viral load rebound near delivery.
HIV viral load rebound is the reemergence of detectable plasma HIV viral load among individuals who previously achieved viral suppression through antiretroviral treatment. It is a form of HIV treatment failure that represents a challenge in the management of the disease.
In a study published in Obstetrics & Gynecology, investigators sought to assess the stability of HIV viral load suppression within 1 month prior to pregnant women receiving antenatal combination antiretroviral therapy (CART).
The investigators used a Canadian provincial perinatal HIV database from 1997 to 2015, to identify patients who had a live birth, received CART for at least 4 weeks, had a viral load measured within 1 month of delivery, and had a least one previous undetectable viral load during pregnancy.
Viral load rebound was defined as viral load greater than 50 copies/mL (or greater than 400 copies/mL for 1997-1998).
Of the 470 women in the database, 318 met inclusion criteria of live birth and CART received for at least 4 weeks.
The results of the study showed that 19 women (6%) experienced viral load rebound with a mean log10 viral load near delivery of 2.71 copies/mL (=513 copies/mL). Six women (325) had a viral load above 1000 copies/mL.
In half of the women, the rebound was detected within 1 day before delivery. Aboriginal ethnicity, cocaine use, and hepatitis c polymerase chain reaction positivity were significantly associated with viral load rebound.
No HIV vertical transmissions were observed, according to the authors.
“Even women attending for HIV care and achieving viral suppression in pregnancy can experience viral load rebound predelivery,” the authors concluded.
An estimated 8500 HIV-positive women give birth in the United States annually, according to the CDC. Between 1994 and 2010, an estimated 21,956 cases of perinatally acquired HIV infections were prevented.
If treated early in the pregnancy, a women’s risk of transmitting HIV to her infant can be reduced to 1% or less.