Antiretroviral therapy and preterm birth in HIV-infected women

Abstract

The use of combination antiretroviral therapy for the prevention of mother to child transmission of HIV infection has achieved vertical HIV transmission rates of <1%. The use of these drugs is not without risk to the mother and infant. Pregnant women with HIV-infection are at high risk of preterm birth (PTB <37 weeks), with 2–4-fold the risk of uninfected women. There is accumulating evidence that certain combinations are associated with higher rates of PTB that others or no antiretroviral treatment. Understanding the pathogenesis of PTB in this group of women will be essential to target preventative strategies in the face of increasing HIV prevalence and rapidly expanding mother-to-child-transmission prevention programmes.

Keywords::

• antiretroviral therapy
• HIV-infection
• lopinavir
• preterm birth
• prevention
• protease inhibitors
• risk factors
• ritonavir
• zidovudine

Financial & competing interests disclosure

Between the 1st of January 2013 to the time of publication, GP Taylor has received fees for the preparation of educational material and consultancy from Abbvie and CE Short has received honoraria for the preparation and delivery of lectures from Janssen, as well as unconditional education grants from Abbvie.

Imperial College is in receipt of research grants from Abbvie, The British HIV Association, The PANNA network, the Wellcome Trust, Leukaemia Lymphoma Research and the Medical Research Council to support the research of the Taylor Group. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Combination antiretroviral therapy has led to dramatic reduction in mother-to-child transmission of HIV with infant infection rates of <1% achievable.

• Advances in therapy have enabled HIV-infected women to have normal vaginal deliveries and in certain settings, the option of breastfeeding.

• The infants of HIV-infected women have a high risk of being born preterm of which up to 50% are born <34 weeks (moderate–severe prematurity).

• The cause of these high rates of preterm birth (PTB) in HIV-infected women is likely to be multifactorial.

• Several studies implicate protease inhibitors as a cause of preterm birth although no mechanism has been identified.

• Lower rates of PTB, in line with the general population, have been observed with older, now less used treatments such as the nucleoside analog reverse transcriptase inhibitor only therapy including zidovudine monotherapy.

• The current hypothesis is that combination antiretroviral therapy alters the cytokine environment of the fetoplacental unit and reduces the threshold for labor initiation.

• Tailored antiretroviral treatment in HIV women perceived to be at high risk of PTB might be a viable risk reduction strategy.