HIV maternal-fetal transmission in a low resources setting in the outskirts of Buenos Aires, Argentina

Purpose of the study

HIV maternal-fetal transmission (MFT-HIV) in Argentina is around 6%, one of the highest rates in Latin America. Most cases occur in the outskirts of Buenos Aires, a highly populated, low resources setting where the hospitals of this study are located. Our objective was to assess reasons, risk factors and percentage of MFT-HIV, characteristics of HIV+ pregnant women (PW), and evaluation of preventive measurements.

Methods

Prospective, descriptive, study of HIV+ PW and their newborns (NB) from 1997 to 2006 in two hospitals of Buenos Aires Province, Argentina.

Summary of results

211 HIV+ mother-child binomium were evaluated, and 171 (81%) NB were studied: nine acquired HIV (5.26%) (at least one PCR+ or ELISA+ at 18 months). Mean mother's age 26.8 years (15–40): MFT+: 29 years vs. MFT-: 27.2 years (p = 0.31). Way of HIV acquisition: sexual (96.2%), intravenous drug use (2.5%), blood transfusion (1.3%); all TMF+ sexual (p = 0.59).

Seventy-three (42.7%) women began HIV follow-up previous to pregnancy: 6 TMF+ vs. 67 TMF- (p = 0.13); 19 (11.1%) before 14 weeks: all NFT-; 36 (21%) between 15–28 weeks: all NFT-, 32 (18.7%) after 29 weeks: all NFT-; and 11 (6.4%) post-partum: 2 TMF+ vs. 9 TMF- (p = 0.0047).

During pregnancy, 134 (63.5%) women received ART: AZT (11.5%), AZT-ddI (0.6%), AZT-3TC (3.6%), AZT-3TC-IDV/RTV (1.2%), AZT-3TC-LPV/RTV (0.6%), AZT-3TC-NFV (7.9%), AZT-3TC-NVP (66.6%), AZT-3TC-SQV/RTV (7.9%); 34 MFT- and 3 MFT+ did not receive (p = 0.38) Viral load (VL) measured previous to labor in 73 (42.7%) women: 43 <1000 (58.9%). VL was not available in 89 MFT- and 9 MFT+ (p = 0.02). 109 (63.7%) were elective Caesarean: 56 MFT- vs. 3 MFT+ (p = 0.11) In 145 (84.4%) cases, i.v. AZT was administered intra-labor; 4 MFT+ vs. 22 MFT- did not receive intra-partum AZT (p = 0.042) One NB died perinatally (0.58%). Mean gestational age: 37.9 weeks. MFT-: 38.0 vs. MFT+: 39.1 (p = 0.0302); eight (4.67%) NB premature, all MFT- (p = 0.49). Mean birth weight 2,895.7 g (1,450–4,500). MFT-: 2,884 g vs. MFT+ 3,093 g (p = 0.0938); 42 NB (24.6%) presented low birth weight; MFT-: 41 vs. MFT+: 1 (p = 0.33).

163 (95.3%) NB received ART: AZT(93.9%), AZT-3TC-NVP (5.52%), AZT-NVP (0.6%); 6 MFT- and 2 TMF+ did not (p = 0.013). Nine (5.26%) NB were breastfed, 7 MFT- vs. 2 MFT+ (p = 0.019).

Conclusion

Beginning of HIV follow-up post-partum, availability of VL result at the moment of delivery, AZT intra-partum, higher gestational age, lack of administration of ART to the newborn, and breastfeeding were significant for HIV-MFT. It is mandatory to re-affirm the importance of the fulfillment of measures destined to diminish the probability of HIV-MFT.