First-trimester markers of aneuploidy in women positive for HIV.

OBJECTIVE

To investigate whether the sonographic and maternal serum biochemical markers used in first-trimester screening for chromosomal abnormalities are altered in pregnancies affected by maternal HIV infection.

DESIGN

Nested case-control study.

SETTING

Routine antenatal visit in a teaching hospital.

POPULATION

Ninety HIV-positive and 450 HIV-negative pregnant women.

METHODS

Findings from first-trimester antenatal visit for calculation of the risk for chromosomal abnormalities were compared between HIV-positive (treated and untreated) and HIV-negative women.

MAIN OUTCOME MEASURES

First-trimester maternal serum free β human chorionic gonadotrophin (free β-hCG) pregnancy-associated plasma protein-A (PAPP-A) and fetal nuchal translucency thickness (NT), were compared.

RESULTS

There were no statistically significant differences between the HIV-positive and HIV-negative women in the median maternal levels of free β-hCG, PAPP-A and fetal NT. However, within the HIV-positive group those receiving antiretroviral treatment (n = 41) had a significantly lower median multiple of the median (MoM) for free β-hCG (0.74, interquartile range [IQR] 0.45-1.32 MoM) than HIV-positive women on no treatment (1.03, IQR 0.76-1.85 MoM; P = 0.006) and HIV-negative women (1.0, IQR 0.68-1.47 MoM; P = 0.003). There was no correlation between the level of free β-hCG or PAPP-A and maternal viral load or CD4(+) count.

CONCLUSIONS

Maternal levels of free β-hCG in treated HIV-positive pregnant women were lower compared with those in non-treated HIV-positive and HIV-negative women, whereas the PAPP-A levels and fetal NT remained unaltered.