Detection of Fetal Fraction During Noninvasive Prenatal Screening in HIV Infected Pregnant Women [21OP

Abstract

INTRODUCTION: To describe the reliability of Noninvasive Prenatal Screening (NIPS) in HIV infected (HIV+) pregnant women. NIPS analyzes cell free fetal DNA which circulates in maternal plasma but originates from the placenta and is quantitated as “fetal fraction” (FF). Sensitivity of NIPS increases with FF. NIPS reliability decreases in certain situations, such as obesity, due to decreased FF. Our study aims to determine if immune system alterations such as HIV or antiretroviral medications impact FF. METHODS: A 2:1 matched case-control study was carried out comparing 20 HIV+ pregnant women to 40 without HIV undergoing NIPS. Univariable and multivariable conditional logistic regression was fit to assess the association between demographic and clinical variables, and FF. Immune status and antiretroviral medications were evaluated in correlation with FF in HIV+ patients. RESULTS: HIV+ patients receiving integrase inhibitors (INI) had lower mean FF than those without INI - 6.18 (SD 3.68) versus 12.87 (SD 6.03) (p= 0.006). HIV + patients with an undetectable viral load (VL) at NIPS had a lower median FF than those with a detectable VL – 6.5 versus 11.8 (p=0.28). INI users had a significantly lower median VL at NIPS compared to non-INI users (p=0.02). CONCLUSION: Integrase inhibitors may play a role in reliability of NIPS in HIV+ women, as reflected by lower FF for patients taking INI. INI use is increasing due to their tolerability and potency, thereby potentially making our findings more significant. Further study is needed to fully elucidate the mechanism for INI and decreased FF.