Contraception use and effectiveness among women in a trial of the diaphragm for HIV prevention

Comparison of pregnancy incidence among African women in a randomized trial of intramuscular depot medroxyprogesterone acetate (DMPA-IM), a copper intrauterine device (IUDs) or a levonorgestrel (LNG) implant for contraception

OBJECTIVE

The objective was to address bias in contraception efficacy studies through a randomized study trial of intramuscular depot medroxyprogesterone acetate (DMPA-IM), a copper intrauterine device (IUDs) and a levonorgestrel (LNG) implant.

STUDY DESIGN

We analyzed data from the Evidence for Contraceptive Options and HIV Outcomes Trial, which assessed HIV incidence among 7829 women from 12 sites in eSwatini, Kenya, South Africa and Zambia seeking effective contraception and who consented to be randomized to DMPA-IM, copper IUD or LNG implant. We used Cox proportional hazards regression adjusted for condom use to compare pregnancy incidence during both perfect and typical (i.e., allowing temporary interruptions) use.

RESULTS

A total of 7710 women contributed to this analysis. Seventy pregnancies occurred during perfect and 85 during typical use. There was no statistically significant difference in perfect use pregnancy incidence among the methods: 0.61 per 100 woman-years for DMPA-IM [95% confidence interval (CI) 0.36-0.96], 1.06 for copper IUD (95% CI 0.72-1.50) and 0.63 for LNG implants (95% CI 0.39-0.96). Typical use pregnancy rates were also largely similar: 0.87 per 100 woman-years for DMPA-IM (95% CI 0.58-1.25), 1.11 for copper IUD (95% CI 0.77-1.54) and 0.63 for LNG implants (95% CI 0.39-0.96).

CONCLUSIONS

In this randomized trial of highly effective contraceptive methods among African women, both perfect and typical use resulted in low pregnancy rates. Our findings provide strong justification for improving access to a broader range of longer-acting contraceptive options including LNG implants and copper IUD for African women.

IMPLICATIONS STATEMENT

Data from this study support recommendations to providers, policy makers and patients that all of these methods provide safe and highly effective contraception for African women.

Contraceptive Use and Pregnancy Incidence Among Women Participating in an HIV Prevention Trial

BACKGROUND

Recent HIV prevention trials required use of effective contraceptive methods to fulfill eligibility for enrollment. We compared pregnancy rates in a subset of participants enrolled in the Microbicide Trials Network protocol (MTN-003), a randomized trial of chemoprophylaxis to prevent HIV acquisition among women aged 18-45 years who initiated depot medroxyprogesterone acetate (DMPA) or combined oral contraceptives (COCs) at enrollment, relative to those already using DMPA or COCs.

METHODS

Data were analyzed from MTN-003 participants from Uganda. Before enrollment, information on contraceptive type and initiation date was obtained. Urine pregnancy tests were performed at monthly follow-up visits. Cox proportional hazards models were used to compare pregnancy incidence among new users (initiated ≤60 days before enrollment) and established users (initiated >60 days before enrollment).

RESULTS

Of 322 women enrolled, 296 were COC or DMPA users, 82 (28%) were new users, and 214 (72%) were established users. Pregnancy incidence was higher among new contraceptive users compared to established users (20.70% vs. 10.55%; adjusted hazard ratio [HR] = 1.66; 95% confidence interval [95% CI] 0.93-2.96). Among DMPA users, pregnancy incidence was 10.20% in new users versus 3.48% in established users (HR = 2.56; 95% CI 0.86-7.65). Among new COC users, pregnancy incidence was 42.67% in new users versus 23.67% in established COC users (adjusted HR = 1.74; 95% CI 0.87-3.48).

CONCLUSIONS

New contraceptive users, regardless of method, at the Uganda MTN-003 site had an increased pregnancy risk compared to established users, which may be due to contraceptive initiation primarily for trial eligibility. New users may benefit from intensive contraceptive counseling and additional contraceptive options, including longer acting reversible contraceptives.

Pregnancy rates in HIV-positive women using contraceptives and efavirenz-based or nevirapine-based antiretroviral therapy in Kenya: a retrospective cohort study

BACKGROUND

Concerns have been raised about efavirenz reducing the effectiveness of contraceptive implants. We aimed to establish whether pregnancy rates differ between HIV-positive women who use various contraceptive methods and either efavirenz-based or nevirapine-based antiretroviral therapy (ART) regimens.

METHODS

We did this retrospective cohort study of HIV-positive women aged 15-45 years enrolled in 19 HIV care facilities supported by Family AIDS Care and Education Services in western Kenya between Jan 1, 2011, and Dec 31, 2013. Our primary outcome was incident pregnancy diagnosed clinically. The primary exposure was a combination of contraceptive method and efavirenz-based or nevirapine-based ART regimen. We used Poisson models, adjusting for repeated measures, and demographic, behavioural, and clinical factors, to compare pregnancy rates among women receiving different contraceptive and ART combinations.

FINDINGS

24,560 women contributed 37,635 years of follow-up with 3337 incident pregnancies. In women using implants, adjusted pregnancy incidence was 1.1 per 100 person-years (95% CI 0.72-1.5) for nevirapine-based ART users and 3.3 per 100 person-years (1.8-4.8) for efavirenz-based ART users (adjusted incidence rate ratio [IRR] 3.0, 95% CI 1.3-4.6). In women using depot medroxyprogesterone acetate, adjusted pregnancy incidence was 4.5 per 100 person-years (95% CI 3.7-5.2) for nevirapine-based ART users and 5.4 per 100 person-years (4.0-6.8) for efavirenz-based ART users (adjusted IRR 1.2, 95% CI 0.91-1.5). Women using other contraceptive methods, except for intrauterine devices and permanent methods, had 3.1-4.1 higher rates of pregnancy than did those using implants, with 1.6-2.8 higher rates in women using efavirenz-based ART.

INTERPRETATION

Although HIV-positive women using implants and efavirenz-based ART had a three-times higher risk of contraceptive failure than did those using nevirapine-based ART, these women still had lower contraceptive failure rates than did those receiving all other contraceptive methods except for intrauterine devices and permanent methods. Guidelines for contraceptive and ART combinations should balance the failure rates for each contraceptive method and ART regimen combination against the high effectiveness of implants.

FUNDING

None.

Pregnancy and contraceptive use among women participating in the FEM-PrEP trial

BACKGROUND

Pregnancy among study participants remains a challenge for trials of new HIV prevention agents despite promotion and provision of contraception. We evaluated contraceptive use, pregnancy incidence, and study drug adherence by contraceptive method among women enrolled in the FEM-PrEP trial of once-daily oral tenofovir disoproxil fumarate and emtricitabine (TDF-FTC) for HIV prevention.

METHODS

We required women to be using effective non-barrier contraception at enrollment. At each monthly follow-up visit, women were counseled on contraceptive use and tested for pregnancy. TDF-FTC adherence was determined by measuring plasma drug concentrations at 4-week intervals. We used Cox proportional hazards models to assess factors associated with incident pregnancy and multivariate logistic regression to examine the relationship between contraceptive method used at enrollment and TDF-FTC adherence.

RESULTS

More than half of women were not using effective contraception before enrollment. Ninety-eight percent of these women adopted either injectable (55%) or oral (43%) contraceptives. The overall pregnancy rate was 9.6 per 100 woman-years. Among injectable users and new users of combined oral contraceptives (COCs), the rates were 1.6 and 35.1, respectively. New users of injectables had significantly greater odds of adhering to TDF-FTC than new COC users [odds ratio (95% confidence interval): 4.4 (1.7 to 11.6), P = 0.002], existing COC users [3.1 (1.3 to 7.3), P = 0.01], and existing injectable users [2.4 (1.1 to 5.6), P = 0.04].

CONCLUSIONS

Women using COCs during FEM-PrEP, particularly new adopters, were more likely to become pregnant and less likely to adhere to study product than injectable users. HIV prevention trials should consider requiring long-acting methods, including injectables, for study participation.

Oral and injectable contraception use and risk of HIV acquisition among women in sub-Saharan Africa

OBJECTIVE

To evaluate the effect of oral and injectable hormonal contraception on the risk of HIV acquisition among women in South Africa and Zimbabwe.

DESIGN

Secondary data analysis of 4913 sexually active women aged 18-49 years followed for up to 24 months in the Methods for Improving Reproductive Health in Africa (MIRA) phase III effectiveness trial of the diaphragm and lubricant gel for HIV prevention.

METHODS

Participants were interviewed quarterly about contraception and sexual behavior and were tested for pregnancy, HIV, and other sexually transmitted infections. We used a Cox proportional hazards marginal structural model, weighted by the inverse probability of hormonal contraception use, to compare the risk of HIV acquisition among nonpregnant women reporting use of combined oral contraceptive pills (COC), progestin-only pills (POP), and/or injectable hormonal contraception to women not using these methods.

RESULTS

During the study, 283 participants seroconverted. Use of oral contraceptives (POP or COC) was not associated with HIV risk [adjusted hazard ratio (HRa) = 0.86, 95% confidence interval (CI) 0.32, 1.78]. Injectable hormonal contraception was associated with a small nonsignificant risk of HIV infection (HR(a) = 1.34, 95% CI 0.75, 2.37). The effect of injectable hormonal contraception was similar in the unweighted site-adjusted only (HR(a) = 1.32, 95% CI 1.00, 1.74) and baseline factor adjusted models (HR(a) = 1.27, 95% CI 0.94, 1.72).

CONCLUSIONS

In this study, oral contraceptives were not associated with HIV acquisition. There is substantial uncertainty in the effect of injectable hormonal contraception on HIV risk. These findings underscore the importance of dual protection with condoms and the need for diverse contraceptive options for women at risk of HIV infection.

Contraception and pregnancy in microbicide trials

The distinctive feature of the human immunodeficiency virus (HIV) epidemic in Sub-Saharan Africa is the burden on women, in particular young women of reproductive age. Consequently, most late-phase effectiveness microbicide clinical trials are conducted in sub-Saharan Africa where fertility rates are high. Because late-phase clinical trials are conducted over prolonged periods of time, women participating in these trials may fall pregnant during the trial. Their unborn babies may be exposed to a drug whose teratogenic potential is unknown if the investigational drug is not withdrawn. High pregnancy rates in such trials may compromise statistical integrity, as women will be withdrawn from the study drug for the duration of the pregnancy. It is therefore imperative for microbicide trials to implement effective contraceptive and pregnancy management programmes that maintain low pregnancy rates and the safety of unborn babies while not compromising the conduct and statistical integrity of the trial.