Guy's & St Thomas' NHS Foundation Trust, London, UK.
AIDS. 2012 Jun 1;26(9):1095-103. doi: 10.1097/QAD.0b013e3283536a6c.
HAART dramatically reduces mother-to-child transmission of HIV allowing vaginal delivery if the viral load is low. This study provides data for the optimum timing of short-term HAART in pregnancy.
Retrospective multicentre cohort study of pregnant women commencing HAART in London and Brighton, UK. Demographics, gestation, drug class, CD4 cell count, and viral load results were collated. Survival curves for reaching a viral load less than 50 copies/ml were stratified by initial HIV viral load. Cox's proportional hazards regression model was adjusted for demographics and immunovirological parameters.
Viral load was less than 50 copies/ml in 292 of 378 pregnancies (77.2%) by delivery. Pretreatment viral load was associated with the time taken, and the proportion achieving a viral load less than 50 copies/ml at (P≤0.001). When baseline viral load was less than 10 ,000 copies/ml, gestational age at HAART initiation did not affect success up to 26.3 weeks gestation. When viral load was more than 10 ,000 copies/ml, deferring HAART past 20.4 weeks reduced the probability of reaching less than 50 copies/ml by delivery (P=0.011). When baseline viral load was more than 100, 000 copies/ml the likelihood of reaching a viral load of less than 50 copies/ml was low (37%: hazard ratio 0.31), and dependent on the length of time on HAART. The hazard ratio for a nonnucleoside reverse transcriptase inhibitor regimen achieving a viral load less than 50 copies/ml compared with a protease inhibitor was 0.7 (95% confidence interval 0.52-0.94).
With a viral load more than 10, 000 copies/ml and especially with a viral load more than 100 ,000 copies/ml, the probability of achieving either less than 50 copies/ml by the time of delivery is compromised by delaying initiation of short-term highly active antiretroviral therapy beyond 20.4 weeks gestation. Current UK and other guidelines for when to commence START may therefore limit the chance of vaginal delivery.
高效抗逆转录病毒疗法（HAART）显著降低了 HIV 母婴传播的风险，如果病毒载量较低，可以允许阴道分娩。本研究提供了妊娠期间短期 HAART 的最佳时机的数据。
这是一项在英国伦敦和布莱顿进行的回顾性多中心队列研究，纳入了开始 HAART 的孕妇。收集了人口统计学、妊娠时间、药物类别、CD4 细胞计数和病毒载量结果。根据初始 HIV 病毒载量，对达到病毒载量小于 50 拷贝/ml 的生存曲线进行分层。使用 Cox 比例风险回归模型调整人口统计学和免疫病毒学参数。
378 例妊娠中，有 292 例（77.2%）分娩时病毒载量小于 50 拷贝/ml。治疗前病毒载量与所需时间以及达到病毒载量小于 50 拷贝/ml 的比例相关（P≤0.001）。当基线病毒载量小于 10,000 拷贝/ml 时，HAART 起始时的妊娠时间不影响在 26.3 周妊娠前的成功率。当病毒载量大于 10,000 拷贝/ml 时，将 HAART 推迟到 20.4 周以后会降低分娩时达到病毒载量小于 50 拷贝/ml 的概率（P=0.011）。当基线病毒载量大于 100,000 拷贝/ml 时，达到病毒载量小于 50 拷贝/ml 的可能性较低（37%：风险比 0.31），且依赖于 HAART 的时间长度。与蛋白酶抑制剂相比，非核苷类逆转录酶抑制剂方案达到病毒载量小于 50 拷贝/ml 的风险比为 0.7（95%置信区间 0.52-0.94）。
对于病毒载量大于 10,000 拷贝/ml，特别是病毒载量大于 100,000 拷贝/ml 的患者，将短期高效抗逆转录病毒治疗的起始时间推迟到 20.4 周妊娠以后，可能会降低在分娩时达到病毒载量小于 50 拷贝/ml 的概率。因此，目前英国和其他国家关于何时开始起始抗逆转录病毒治疗的指南可能会限制阴道分娩的机会。
