Prevention

Discussions about prevention strategies will vary, depending on which of the following a woman is trying to prevent:

  • Transmitting HIV or other sexually transmitted infections (STIs) to a partner
  • Acquiring HIV or another STI from a partner
  • Becoming pregnant
  • Transmitting HIV while trying to conceive.

A barrier method is needed to prevent transmission of HIV or other STIs. There are both male and female condoms that can be used. Beyond this, is the possibility of pre- or post-exposure prophylaxis for the exposed partner. Microbicides to prevent HIV transmission have been under development for years, but an effective one has not yet been developed.

Although the risk of transmitting HIV is greatly reduced for an individual with chronically suppressed viral load, if the partner has an existing STI, there is a bi-directional risk of infection to both partners if a condom is not used. Use of a diaphragm or intrauterine device will prevent pregnancy, but a barrier method is still needed to prevent HIV transmission.

Intrauterine devices (IUDs) are effective means of suppressing conception. In the late 1990s, there was concern that they could cause pelvic infection or increased blood loss, but a recent meta-analysis of the scant literature on this topic in HIV-positive women seems to indicate they can be safely used.1

A Zambian study in which nearly 600 women were randomised to use of a copper IUD or hormonal contraception for two years found a greater, but not statistically significant risk of disease progression in the group randomised to hormonal contraception.2 

In addition, a small Finnish study of 12 HIV-positive women who used the levonorgestrel-releasing intrauterine system (LNG-IUS) experienced a significant reduction in menstrual bleeding with slight increases of serum haemoglobin and ferritin levels. In women using antiretroviral therapy, the genital shedding of HIV-RNA was 10% both before and up to one year after after IUD insertion.3

For prevention purposes, dual contraception with a hormonal agent for pregnancy prevention and a condom to reduce viral transmission is advised. Hormonal contraceptives can be delivered in pill form, in a subdermal implant, with an injection, with use of a patch. 

Many hormonal contraceptives may have interactions with the metabolism of antiretroviral drugs or other medications. These are briefly discussed in the Drug interactions section above.  

Hormonal contraceptives and HIV

A number of studies have suggested that hormonal contraception use might be associated with CD4 cell depletion in antiretroviral-naive women. In a multicountry cohort composed of more than 4000 HIV-positive women from 13 sites in Africa and Asia, disease progression and/or death was not associated with the use of hormonal contraceptives in pill, implant, or injectable form. In this cohort of antiretroviral-naive women, approximately 3000 women used a non-hormonal method of contraception or none at all, over 800 used an implant or injectable method, and over 200 used oral contraceptive pills.4 

To look at the question of whether contraceptive use increases the risk for HIV infection, a prospective study in more than 6100 HIV-negative women, enrolled from family planning clinics in Uganda, Zimbabwe, and Thailand, were followed for two years. The women were 18 to 35 years of age. Women in the study used combined oral contraceptives, depot-medroxyprogesterone acetate, or no contraception. Investigators could not find an association between hormonal contraceptive use and HIV acquisition. Oddly and thus far unexplained was the finding that in women using hormonal contraception, the presence of herpes simplex virus-2 infection had a protective effect against HIV acquisition, while women without HSV-2 had an elevated risk.5

There is an indication from another study that injectable progestin contraception users might have a higher susceptibility to sexually transmitted infections, including HIV, that could be avoided with consistent condom use.6

Some early studies that did find an association between hormonal contraceptive use and HIV acquisition were conducted in populations with a high occupational or behavioural risk for acquiring HIV and/or other sexually transmitted diseases – with results that might not be applicable to age-matched women drawn from a more general population. There seems to be some evidence of a link between contraceptive method and STI acquisition that is related to younger age, but this is yet another unanswered question.

References

  1. Browne H et al. Using an intrauterine device in immunocompromised women. Obstet Gynecol 112(3):667-669, 2008
  2. Stringer E et al. A randomized trial of the intrauterine contraceptive device vs hormonal contraception in women who are infected with the human immunodeficiency virus. Am J Obstet Gynecol 197:144.e1–144.e8, 2007
  3. Heikinheimo O et al. The levonorgestrel-releasing intrauterine system (LNG-IUS) in HIV-infected women--effects on bleeding patterns, ovarian function and genital shedding of HIV. Hum Reprod 21(11): 2857-2861, 2006
  4. Stringer E et a. Hormonal contraception and HIV disease progression: a multicountry cohort analysis of the MTCT-Plus Initiative. AIDS 23(S1): S69-77, 2009
  5. Morrison CS et al. Hormonal contraception and the risk of HIV acquisition. AIDS 21(1):85-95, 2007
  6. Pettifor A et al. Use of injectable progestin contraception and risk of STI among South African women. Contraception 80(6):555-560, 2009