NEW ORLEANS – There were no cases of HIV transmission to infants born of a second pregnancy to mothers who maintained viral suppression between their two pregnancies, a study showed.
In a retrospective cohort of 103 women, the mother-to-child transmission rate was 9% among women whose interpregnancy viral load was more than 1,000 copies/mL. But among those with a load of less than 1,000 copies/mL, the transmission rate was 0, Dr. Robert Stewart said at the annual Pregnancy Meeting, sponsored by the Society for Maternal-Fetal Medicine.
Dr. Robert Stewart
The data support the concept of treating HIV to help protect babies as well as mothers, said Dr. Stewart of the University of Texas Southwestern Medical Center, Dallas.
"Right now there are no recommendations for HIV treatment between pregnancies, or treatment for the benefit of the fetus," he said. The only treatment guidelines suggest that pregnant women be treated as nonpregnant women are, for their own health.
Dr. Stewart examined the issue in a cohort of 103 women who had a suppressed HIV load (less than 1,000 copies/mL) at their index pregnancy, and were seen at the same institution for their next pregnancy.
At baseline, the women were about 24 years old. Most (71%) were black. Gestational age at the first prenatal visit was 14 weeks; at the next pregnancy, the women came in earlier – a mean of 12 weeks. They also had more prenatal visits with their second pregnancy (mean of 10 compared with 9).
At presentation for the index pregnancy, the mean viral load for all women was 1,860 copies/mL, but the range was wide (0-21,700 copies/mL). The mean CD4 cell count was 456/mcL. Just over a third (35%) were already on antiretroviral therapy.
At presentation for the subsequent pregnancy, the overall mean viral load was 1,120 copies/mL (0-145,000 copies/mL). The mean CD4 count was 479 cells/mcL. These differences were not statistically significant. However, at the subsequent pregnancy, significantly more women were on antiretroviral therapy (56%).
The second pregnancy occurred a mean of 2.6 years later in both groups. At presentation for the second pregnancy, 57 had maintained that level of suppression and 46 had not. At that time, the mean viral load was 0 in those who had maintained suppression and 10,160 copies/mL among those who had not – a significant difference. CD4 cell count also was significantly different (596 vs. 342 cells/mcL). Significantly more of those who had maintained suppression were on antiretroviral therapy at the second pregnancy (75% vs. 59%).
By the time of delivery, however, HIV indices had improved in the group that had not maintained suppression. At that time, their mean viral load was also 0. Their CD4 count had increased to 427 cells/mcL, and 93% were on antiretroviral therapy.
There were no significant differences in the clinical parameters of the second pregnancy between those who had maintained suppression and those who had not. These included gestational age at delivery (38 weeks); birth weight (about 3,000 g); the use of intrapartum zidovudine (more than 90% of each group); cesarean delivery (32% vs. 52%; P = .18); length of labor; length of ruptured membranes; and incidence of clinical chorioamnionitis.
Vertical transmission was significantly higher among women who had not maintained an interpregnancy suppression (9% vs. 0 infants).
Dr. Stewart said he had no relevant financial disclosures.
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