Intrapartum fetal invasive procedures and perinatal transmission of HIV

To study the effect of intrapartum use of fetal invasive procedures (scalp electrodes or scalp pH sampling) on perinatal transmission rate of HIV.

We compared the perinatal transmission of 57 HIV pregnancies in which invasive procedures (IP) were performed with a control group of 214 pregnancies without IP. We controlled for potentially risk factors (maternal CD4 level, gestational age, antiretroviral therapy use, duration of rupture of membranes (ROM), length of labor and mode of delivery) by stratification and logistic regression.

Transmission rate in the group with IP was 26.3% (15/57) versus 13.6% (29/214) in the control group, relative risk (RR) 1.9, 95% CI (1.1-3.4). By logistic regression we observed three significant factors involved in transmission of HIV: low maternal CD4 level (odds ratio (OR)=3.3, 95% CI=1.2-9.4), duration of ROM (OR=2.9, 95% CI=1.1-7.9) and IP use (OR=3.5, CI 95%=1.2-9.6). Interaction between duration of ROM and IP are also significant (OR=5.1, CI 95%=1.5-17.5).

Intrapartum use of fetal scalp electrodes or fetal scalp pH sampling increases the perinatal transmission of HIV and should therefore be avoided in HIV patients.