Presentation with late stage HIV in women diagnosed during pregnancy
Polly Clayden, HIV i-Base
HIV-positive women are frequently unaware of their status prior to antenatal testing.
Late diagnosis of HIV results in some advanced management considerations. The extent to which this occurs in pregnancy in Europe has not previously been quantified, nor have the implications for maternal and child health.
Claire Townsend from the European Collaborative Study presented data from an analysis performed to quantify this occurrence within the cohort, describe management strategies and the impact of late diagnosis on MTCT, prematurity and low birth weight.
The investigators defined late diagnosis as women diagnosed antenataly with CD4 count <200 cells/mm3. The analyses used logistic regression and linear mixed effects models.
Date of first positive HIV test was available for 3605 women, of which 1256 had CD4 data available.
Overall 654 (53%) were white, 499 (41%) black and 73 (6%) were of other ethnicities. Of these 15% (185/1256) had late stage diagnoses. This proportion has increased over time with 12% between 1985-89 and 19% between 2005-2008, p=0.24.
The median baseline CD4 count was 140 cells/mm3 (IQR 90-147) among the late diagnosis women vs 460 cells/mm3 (IQR 333-650) among non-late diagnosis women. Of the late diagnosis group, 11% (n=20) had an AIDS-defining illness in pregnancy.
In logistic regression analysis limited to 613 women enrolled after 1996, the investigators found adjusted late diagnosis rates were positively associated with black African ethnicity vs white ethnicity (OR 2.02; 95%CI 1.17-3.48, p=0.01) and older maternal age (OR 2.17; 95% CI 1.10-4.25, p=0.02) for women aged 30-34 years vs <25 years.
More women with late diagnosis received antenatal HAART than other women 85% (94/110) vs 67% (388/580), p< 0.001. The median duration of HAART was 16.9 (IQR 11.6-20.7) weeks vs 13 (IQR 11.6-20.7) for women with late stage and non-late stage diagnosis respectively.
Adjusting for time of measurement and type and duration of regimen, late stage diagnosis was associated with a significantly higher viral load throughout pregnancy, +0.29 log copies/mL vs non late-stage diagnosis women, p<0.001. The estimated mean viral loads at time of delivery were 2.94 log copies/mL and 2.65 log copies/mL for late diagnosis and non-late diagnosis women respectively.
More infants born to women with late diagnosis were premature, 24.0% (44/183) vs 13.7% (145/1062), p< 0.001 and of low birth weight, 27.5% (46/167) vs 16.1% (165/1022), p< 0.001 than other infants.
In the period 2000-08, MTCT rates were similar, 3.0% (95%CI 0.37-10.5) and 1.5% (95%CI 0.5-3.51), p=0.4 in the late diagnosis and non-late diagnosis groups respectively.
This analysis found that an increasing minority of HIV-positive women in Europe, newly diagnosed through antenatal testing, already has advanced disease. Although these women are more likely to initiate HAART, and to do so earlier, they still have worse pregnancy outcomes than women with better functioning immune systems.
Barriers preventing timely access of women to HIV testing are important to address, both for the health of the mother and her infant. Dr Thorne concluded.
Thorne CN et al. Presentation with late stage HIV disease at diagnosis of HIV infection in pregnancy. 5th IAS Conference, Cape Town, South Africa.19-22 July 2009. Poster abstract TUAC103.