Elsevier

Life Sciences

Volume 88, Issues 21–22, 23 May 2011, Pages 922-925
Life Sciences

Minireview
Mother-to-child transmission of HIV-1 in the era prior to the availability of combination antiretroviral therapy: The role of drugs of abuse

https://doi.org/10.1016/j.lfs.2011.03.006Get rights and content

Abstract

Since the use of combination antiretroviral therapy (HAART) to treat pregnant women, the rate of mother-to-child transmission (MTCT) of HIV in the United States has dropped dramatically to less than 2%. With this, the principal determinants of the risk of transmission are the maternal viral load and her use of antiretroviral therapy (ART). However, in the pre-HAART era, the MTCT ranged from 12 to 45% and was influenced by a variety of risk factors for transmission including no ART during pregnancy or delivery, advanced maternal HIV infection (high viral load, low CD4 count, and AIDS diagnosis), prolonged rupture of membranes, first-born of twins, prematurity/low birth weight, chorioamnionitis, vaginal delivery or non-elective Cesarean section, and maternal drug use. Several studies in the pre-HAART era found maternal illicit drug use to be an independent predictor of MTCT. Reasons for this association may be both behavioral and biological. Drug use is associated with poor adherence to ART and medical care. Opioids enhance infection of macrophages by HIV.

Introduction

In 1994, the ACTG 076 study demonstrated that the administration of zidovudine (ZDV) to the HIV-infected pregnant woman during the second and third trimester of pregnancy and to her newborn reduced the rate of mother-to-child transmission (MTCT) of HIV-1 (HIV) by two-thirds, from 25.5% to 8.3% (Connor et al., 1994). Since this landmark study, advances in antiretroviral therapy and improvements in the obstetrical management of HIV-infected pregnant women let to a dramatic drop in the rate of MTCT in the United States. With the use of combination highly active antiretroviral therapy (HAART) during pregnancy, the rate of MTCT of HIV in the United States is now less than 2% (Cooper et al., 2002) with fewer than 200 HIV-infected infants born each year (McKenna and Hu, 2007). In the post-HAART era, the principal determinants of the risk of transmission are the maternal viral load and her use of potent antiretroviral therapy (ART) (Mofenson et al., 1999).

However, prior to HAART, the rate of MTCT ranged from 12 to 45% (Bryson, 1996). A variety of risk factors for transmission was identified which accounts for the differing rates of transmission observed in different studies (Table 1). These include advanced maternal HIV infection (high viral load, low CD4 count, and AIDS diagnosis), no use of ART during pregnancy or delivery, prolonged rupture of membranes, vaginal delivery or non-elective Cesarean section (vs. elective C. section), placental inflammation/chorioamnionitis, birth order (first-born of twins), prematurity/low birth weight, and maternal drug use (Bryson, 1996). Clearly, many of these factors are correlated with each other.

Section snippets

Contribution of drug use to MTCT

A number of studies of risk factors for MTCT in the pre-HAART era suggested that maternal illicit drug use is associated with an increased risk of MTCT (Table 2). The Mothers and Infants Cohort Study, which enrolled HIV-infected pregnant women in New York between 1986 and 1991, had an overall rate of MTCT of 24% (Bulterys et al., 1997). As expected, women with a %CD4+ of 20% or more had a lower rate of MTCT than those with a %CD4+ less than 20% (19% vs. 31% respectively). Illicit drug use was

Rational for drug use increasing the risk of MTCT

Reasons for an association between drug use and perinatal transmission may be both behavioral and biological. A likely explanation is poor adherence to antiretroviral therapy with drug use, resulting in a higher maternal HIV viral load and leading to a higher rate of perinatal transmission. Injection drug users are less likely to be in medical care and less likely to be receiving antiretroviral therapy than non-users (Celentano et al., 1998, Strathdee et al., 1998) and are at greater risk for

Conflict of interest statement

The author declares that he has no conflicts of interest.

References (28)

  • I.J. Chasnoff et al.

    Cocaine and pregnancy: clinical and toxicological implications for the neonate

    Clin Chem

    (1989)
  • E.M. Connor et al.

    Reduction of maternal-infant transmission of human immunodeficiency virus type 1 with zidovudine treatment. Pediatric AIDS Clinical Trials Group Protocol 076 Study Group

    N Engl J Med

    (1994)
  • E.R. Cooper et al.

    Combination antiretroviral strategies for the treatment of pregnant HIV-1-infected women and prevention of perinatal HIV-1 transmission

    J Acquir Immune Defic Syndr

    (2002)
  • P.M. Garcia et al.

    Maternal levels of plasma human immunodeficiency virus type 1 RNA and the risk of perinatal transmission. Women and Infants Transmission Study Group

    N Engl J Med

    (1999)
  • Cited by (11)

    View all citing articles on Scopus
    View full text