Contraception and pregnancy in microbicide trials

Experience with Contraceptive Dosage Forms and Interest in Novel PrEP Technologies in Women

New pre-exposure prophylaxis (PrEP) strategies tailored to the needs and expectations of individuals at risk of HIV acquisition are needed. In the CAPRISA 082 prospective cohort study in KwaZulu-Natal, South Africa, sexually active women aged 18 to 30 reported, through interviewer-administered questionnaires, on their prior contraceptive experience and interest in both approved and potential future PrEP dosage forms (oral PrEP, long-acting injectable PrEP, and PrEP implants) between March 2016 and February 2018. Univariable and multivariable Poisson regression models with robust standard errors were used to detect associations between women's prior and current contraceptive use and interest in PrEP options. Of 425 women enrolled, 381 (89.6%) had used at least one modern female contraceptive method previously, with injectable depot medroxyprogesterone acetate (DMPA) being used by 79.8% (n = 339). Women were more likely to show interest in a future PrEP implant if they were currently using (aRR 2.1, CI 1.43-3.07, p = 0.0001) or had ever used (aRR 1.65, CI 1.14-2.40, p = 0.0087) a contraceptive implant, and were more likely to choose an implant as their first choice method than the implant-naïve (current users aRR 3.2, CI 1.79-5.73, p < 0.0001; "ever" users aRR 2.12, CI 1.16-3.86, p = 0.0142). Women were more interested in injectable PrEP if they had used injectable contraceptives (current users aRR 1.24, CI 1.06-1.46, p = 0.0088; "ever" users aRR 1.72, CI 1.20-2.48, p = 0.0033); and were more interested in oral PrEP if they had ever used oral contraceptives (aRR 1.3, CI 1.06-1.59, p = 0.0114). This apparent relationship between women's contraceptive experience and their interest in novel forms of PrEP in an equivalent dosage form may play a future role in strengthening HIV prevention efforts in women at high risk of HIV acquisition.

Views among Malawian women about joining HIV prevention clinical trials when pregnant

BACKGROUND

The pressing need to expand the biomedical HIV prevention evidence base during pregnancy is now increasingly recognized. Women's views regarding participation in such trials and initiating PrEP while pregnant are critical to inform evolving policy and best practices aimed at responsibly expanding evidence-based access for this population.

METHODS

We conducted 35 semi-structured interviews with reproductive-aged women in Malawi in the local language, Chichewa. Participants were HIV-negative and purposively sampled to capture a range of experience with research during pregnancy. Women's perspectives on enrolling in three hypothetical HIV prevention trial vignettes while pregnant were explored, testing: (1) oral PrEP (Truvada) (2) a vaginal ring (dapivirine), and (3) a randomized trial comparing the two. The vignettes were read aloud to participants and a simple visual was provided. Interviews were audio-recorded, transcribed, translated, and coded using NVivo 11. Thematic analysis informed the analytic approach.

RESULTS

A majority of women accepted participation in all trials. Women's views on research participation varied largely based on their assessment of whether participation or nonparticipation would best protect their own health and that of their offspring. Women interested in participating described power dynamics with their partner as fueling their HIV exposure concerns and highlighted health benefits of participation-principally, HIV protection and access to testing/treatment and ancillary care, and perceived potential risks of the vignettes as low. Women who were uninterested in participating highlighted potential maternal and fetal health risks of the trial, challenges of justifying prevention use to their partner, and raised some modality-specific concerns. Women also described ways their social networks, sense of altruism and adherence requirements would influence participation decisions.

CONCLUSIONS

The majority of participants conveyed strong interest in participating in biomedical HIV prevention research during pregnancy, largely motivated by a desire to protect themselves and their offspring. Our results are consistent with other studies that found high acceptance of HIV prevention products during pregnancy, and support the current direction of HIV research policies and practices that are increasingly aimed at protecting the health of pregnant women and their offspring through responsible research, rather than defaulting to their exclusion.

Women's views about contraception requirements for biomedical research participation

The scientific and ethical importance of including women of reproductive age in biomedical research is widely acknowledged. Concerns about preventing fetal exposure to research interventions have motivated requirements for contraception among reproductive aged women in biomedical studies-often irrespective of risks and benefits or a woman's actual potential for pregnancy, raising important questions about when such requirements are appropriate. The perspectives of women themselves on these issues are largely unexplored. We conducted 140 interviews, 70 in the U.S. and 70 in Malawi, with women either living with or at-risk for HIV, exploring their views about the practice of requiring contraception in clinical trials. A majority of women interviewed from both countries indicated overall support for the practice, with seven themes characterizing advantages and disadvantages raised: reproductive control, health effects, prevention of fetal harm, burden on women, deferral to authority, autonomy regarding enrollment and birth control method, and relationship concerns. While women in the US frequently raised prevention of fetal harm as a key advantage, many other positives noted by women in both countries were related to contraception use in general, not specific to a trial context. With regard to disadvantages, U.S. women tended to focus on biomedical risks such as side effects and impact on fertility, whereas Malawian women focused on the social risks of contraception requirements, including violations of trust in marital relations and suspicions of potential infidelity. Given the potential benefits and burdens highlighted, contraception in research should be sensitive to actual fetal risk assessments; directed where justified at optimizing effective pregnancy prevention; responsive to women's reproductive preferences; and made available as an ancillary benefit even where risk thresholds do not justify requirement-in order to facilitate trials that are both ethical and robustly oriented around the interests and lives of women who will participate in them.

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 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.

Pregnancy incidence and risk factors among women participating in vaginal microbicide trials for HIV prevention: systematic review and meta-analysis

Introduction

Pregnancy is contraindicated in vaginal microbicide trials for the prevention of HIV infection in women due to the unknown maternal and fetal safety of the microbicides. Women who become pregnant are taken off the microbicide during pregnancy period but this result in reduction of the power of the trials. Strategies to reduce the pregnancy rates require an understanding of the incidence and associated risk factors of pregnancy in microbicide trials. This systematic review estimates the overall incidence rate of pregnancy in microbicide trials and describes the associated risk factors.

Methods

A comprehensive literature search was carried out to identify eligible studies from electronic databases and other sources. Two review authors independently selected studies and extracted relevant data from included studies. Meta-analysis of incidence rates of pregnancy was carried out and risk factors of pregnancy were reported narratively.

Results

Fifteen studies reporting data from 10 microbicide trials (N=27,384 participants) were included. A total of 4,107 participants (15.0%) fell pregnant and a meta-analysis of incidence rates of pregnancy from 8 microbicide trials (N=25,551) yielded an overall incidence rate of 23.37 (95%CI: 17.78 to 28.96) pregnancies per 100 woman-years. However, significant heterogeneity was detected. Hormonal injectable, intra-uterine device (IUD) or implants or sterilization, older age, more years of education and condom use were associated with lower pregnancy. On the other hand, living with a man, history of pregnancy, self and partner desire for future baby, oral contraceptive use, increased number of unprotected sexual acts and inconsistent use of condoms were associated with higher pregnancy.

Conclusions

The incidence rate of pregnancy in microbicide trials is high and strategies for its reduction are urgently required in order to improve the sample size and power of these trials.