Injectable progestin contraceptive use and risk of HIV infection in a South African family planning cohort.
OBJECTIVE
To investigate whether the incidence of HIV infection is higher among sexually active women using depot medroxyprogesterone acetate (DMPA) or noresthisterone enanthate (NET-EN) injections for contraception than among women using nonhormonal or no contraception.


METHODS
Five hundred and fifty-one initially HIV-negative women were followed up for a total of 491 person-years. Participants were interviewed, counselled, examined, tested for HIV and other STIs, and treated, at three monthly intervals for 1 year.


RESULTS
There was no significant association between progestin contraceptive use and HIV infection (rate ratio 1.1, 95% CI 0.5 to 2.8; log-rank test, p=.73). In proportional hazards regression, the only significant hazard ratios for HIV acquisition were prevalent Neisseria gonorrhoea (5.2; 95% CI 1.1 to 23.7, p=.035) and Trichomonas vaginalis (4.8; 95% CI 1.0 to 22.8, p=.049); bacterial vaginosis was marginally significant (2.8; 95% CI 1.0 to 8.3, p=.057). The adjusted hazard ratios for NET-EN and DMPA were 1.76 (95% CI 0.64 to 4.84) and 0.46 (95% CI 0.06 to 3.79), respectively, relative to nonuse. Five hundred and twelve of 551 women had one or more confirmed STIs during the study.


CONCLUSIONS
There is no evidence of an association between HIV infection and injectable contraceptives. Due to the limited power of this study and because similar studies have not included young women using NET-EN, we recommend that further research be carried out to focus on the use of NET-EN and HIV acquisition in high risk groups.
Kleinschmidt
Immo
I
London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK. Immo.kleinschmidt@lshtm.ac.uk
Rees
Helen
H
Delany
Sinead
S
Smith
Dawn
D
Dinat
Natalya
N
Nkala
Busi
B
McIntyre
James A
JA
D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D003271:Contraceptive Agents, Female / Q000008:administration & dosage*; D003692:Delayed-Action Preparations; D005193:Family Planning Services; D005260:Female; D015658:HIV Infections / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D006801:Humans; D015994:Incidence; D008525:Medroxyprogesterone / Q000008:administration & dosage*; D009640:Norethindrone / Q000008:administration & dosage / Q000031:analogs & derivatives*; D015995:Prevalence; D013019:South Africa / Q000453:epidemiology
D003271:Contraceptive Agents, Female; D003692:Delayed-Action Preparations; D008525:Medroxyprogesterone; C024319:norethindrone enanthate; D009640:Norethindrone