Pregnancy Risk Among Oral Contraceptive Pill, Injectable Contraceptive, and Condom Users in Uganda, Zimbabwe, and Thailand

Drug interactions between hormonal contraceptives and antiretrovirals

OBJECTIVE

To summarize published evidence on drug interactions between hormonal contraceptives and antiretrovirals.

DESIGN

Systematic review of the published literature.

METHODS

We searched PubMed, POPLINE, and EMBASE for peer-reviewed publications of studies (in any language) from inception to 21 September 2015. We included studies of women using hormonal contraceptives and antiretrovirals concurrently. Outcomes of interest were effectiveness of either therapy, toxicity, or pharmacokinetics. We used standard abstraction forms to summarize and assess strengths and weaknesses.

RESULTS

Fifty reports from 46 studies were included. Most antiretrovirals whether used for therapy or prevention, have limited interactions with hormonal contraceptive methods, with the exception of efavirenz. Although depot medroxyprogesterone acetate is not affected, limited data on implants and combined oral contraceptive pills suggest that efavirenz-containing combination antiretroviral therapy may compromise contraceptive effectiveness of these methods. However, implants remain very effective despite such drug interactions. Antiretroviral plasma concentrations and effectiveness are generally not affected by hormonal contraceptives.

CONCLUSION

Women taking antiretrovirals, for treatment or prevention, should not be denied access to the full range of hormonal contraceptive options, but should be counseled on the expected rates of unplanned pregnancy associated with all contraceptive methods, in order to make their own informed choices.

FIGO's ethical recommendations on female sterilisation will do more harm than good: a commentary

The International Federation of Gynecology and Obstetrics (FIGO) Committee for the Ethical Aspects of Human Reproduction and Women's Health advises against tubal occlusion (TO) performed at the time of caesarean section (CS/TO) or following a vaginal delivery (VD/TO) if this sterilisation has not been discussed with the woman in an earlier phase of her pregnancy. This advice is neither in accordance with existing medical custom nor evidence based. Particularly in less-resourced locations, adherence to it would deny much wanted one-off sterilisation opportunities to hundreds of thousands of women, many of whom have no reliable contraceptive alternative. To be sure, a well-timed discussion in pregnancy about a potential peripartum TO is preferable and, if conducted as a matter of course (as the Committee appears to promote), would represent an enormous improvement on current practice. Earlier counselling has the advantage that it results in fewer women who regret having rejected the CS/TO or VD/TO option. However, there is no evidence that earlier counselling leads to a smaller proportion of regretted sterilisations. Consequently, where early TO counselling has been impossible, forgotten or deliberately omitted on pronatalist, traditional, financial, cultural or religious grounds, offering a perinatal sterilisation belatedly and in an unbiased, culturally sensitive manner is often verifiably better than not presenting that option at all, notably where high parity and uterine scars are particularly dangerous. Belated counselling, as will be demonstrated in this paper, saves many lives. The Committee's blanket rejection of belated counselling on perinatal sterilisation is therefore unjustified.

Pre-exposure prophylaxis for HIV-1 prevention does not diminish the pregnancy prevention effectiveness of hormonal contraception

BACKGROUND

For women at risk of HIV-1, effective contraception and effective HIV-1 prevention are global priorities.

METHODOLOGY

In a clinical trial of pre-exposure prophylaxis (PrEP) for HIV-1 prevention in HIV-1-serodiscordant couples, we estimated the effectiveness of hormonal contraceptives (oral contraceptive pills, injectable depot medroxyprogesterone acetate, and hormonal implants) for pregnancy prevention relative to no contraception among 1785 HIV-1-uninfected women followed up to 36 months. We compared the effectiveness of each method among women assigned PrEP versus placebo. Contraception was not required for participation, but was offered on-site and was recorded monthly; incident pregnancy was determined by monthly urine testing.

RESULTS

For women using no contraception, overall pregnancy incidence was 15.4% per year. Women reporting oral contraceptive use had comparable pregnancy incidence to women using no contraception, and this lack of contraceptive effectiveness was similar for those assigned PrEP and placebo (17.7 and 10.0% incidence per year, respectively; P-value for difference in effect by PrEP use = 0.24). Women reporting injectable contraception had reduced pregnancy incidence compared to those reporting no contraception, which did not differ by arm (PrEP 5.1%, placebo 5.3% per year; P-value for difference = 0.47). Contraceptive effectiveness was highest among women using implants (pregnancy incidence <1% per year in both arms).

CONCLUSION

PrEP had no adverse impact on hormonal contraceptive effectiveness for pregnancy prevention. As seen previously in similar populations, women reporting contraceptive pill use had little protection from pregnancy, possibly due to poor adherence. Injectable or implantable hormonal contraception and PrEP provide effective prevention for pregnancy and HIV-1.

Efficacy of a combined contraceptive regimen consisting of condoms and emergency contraception pills

Background

To evaluate and compare the effectiveness of the combined regimen (consisting of condoms and emergency contraception pills (ECP)) and using condoms only for the purpose of preventing pregnancy.

Methods

One-thousand-five-hundred-and-sixty-two (1,562) couples as volunteers enrolled at nine centers in Shanghai. Eight-hundred-and-twelve (812) were randomized to use male condoms and ECP (i.e., Levonorgestrel) as a back-up to condoms (the intervention group) and 750 to use male condoms only(the control group), according to their working unit. Participants were visited at admission and at the end of 1, 3, 6, 9, and 12 months. The cumulative life table rates were calculated for pregnancy and other reasons for discontinuation.

Result

The gross cumulative life table rates showed that the cumulative discontinuation rates for all reasons during the year of follow-up in the condoms plus emergency contraception group and the condoms only group were 7.76 ± 0.94 and 6.61 ± 0.91, respectively, per 100 women (χ2 = 0.41, p = 0.5227). The cumulative gross pregnancy rate of the condoms plus emergency contraception group and the condoms only group were 2.17 ± 0.52 and 1.25 ± 0.41, respectively, per 100 women (χ2 = 1.93, p = 0.1645). The Pearl Index in the condoms plus emergency contraception group and the condoms only group were 2.21% and 1.26%, respectively.

Conclusion

Male condoms remain a highly effective contraceptive method for a period of one year while consistently and correctly used. In addition, the lowest pregnancy rate followed from perfect use condom.

Nevirapine-based antiretroviral therapy does not reduce oral contraceptive effectiveness

OBJECTIVE

To evaluate the effect of nevirapine-containing antiretroviral therapy (ART) on combined oral contraceptive (COC) effectiveness.

DESIGN

Nonrandomized prospective clinical trial.

METHODS

We enrolled HIV-infected women aged 18-35 years in South Africa and Uganda who had regular menses, were sexually active, and had no medical contraindications to COC use. We enrolled 196 women taking nevirapine-containing ART and 206 women not yet eligible for ART as a control group. We treated all participants with low-dose COCs. Our main outcomes were ovulation and pregnancy rates. We estimated ovulation in the first two cycles using weekly serum progesterone and tested for pregnancy monthly for 24 weeks.

RESULTS

The median age of participants was 29 and their median CD4 cell count was 486. In the ART group, 43 of 168 (26%) ovulated in cycle 1, 30 of 163 (18%) in cycle 2, and 18 of 163 (11%) in both cycles. In the non-ART group, 26 of 168 (16%) ovulated in cycle 1, 31 of 165 (19%) in cycle 2, and 20 of 165 (12%) in both cycles. We found no significant difference in ovulation rates between groups: unadjusted odds ratio 1.36 (95% confidence interval 0.85-2.18). Pregnancy rates also did not differ: 10.0 per 100-women-years in the ART group and 10.1 per 100-women-years in the non-ART group. Self-reported COC adherence, condom use, vaginal bleeding, and adverse events were similar. Five serious adverse events were reported, all in the non-ART group.

CONCLUSION

ART use did not affect risk of ovulation or pregnancy in women taking COCs, suggesting that nevirapine-containing ART does not interfere with COC contraceptive effectiveness.

Hormonal contraception and HIV: the methods have confused the message

OBJECTIVE

To examine different scenarios through which confounding by condom use may lead to inaccurate conclusions about the effect of hormonal contraception on HIV acquisition in women.

DESIGN AND METHODS

Scenario analyses were conducted to evaluate the impact of coarse adjustment for condom use and condom misreporting on adjusted relative risk estimates for HIV acquisition in injectable hormonal contraception (IHC) users vs. nonusers.

RESULTS

Analyses crudely accounting for condom use through a binary variable result in biased hormonal contraception-related risk estimates if condoms are used during follow-up periods in which any unprotected sex is reported and condom use differs by hormonal contraception use. We found that over-reporting of condom use is plausible in at least one recent study, as demonstrated by high pregnancy rates given, reported IHC and condom use. Over-reporting of condom use also biases estimates, typically leading to underestimation of IHC-related risk if over-reporting is the same among IHC and non-hormonal contraception users, and overestimation of IHC-related risk if condom misreporting is differential by IHC use. The impact of misreported condom use is most pronounced in study populations with high condom uptake.

CONCLUSIONS

Discrepant findings in hormonal contraception-HIV-related research may result from inadequate measurement or adjustment for confounding by condom use. Future studies should precisely account for condom use in statistical analyses. Studies should aim to quantify the degree of condom use misreporting, by comparing reported condom use to pregnancy, HIV or other sexually transmitted infection rates, and if possible, testing stored genital swabs for prostate-specific antigen or Y chromosome.

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

BACKGROUND

There is little data on contraceptive effectiveness or use patterns from sub-Saharan Africa.

STUDY DESIGN

We analyzed data from women at risk of pregnancy (n=4905) in the Methods for Improving Reproductive Health in Africa trial of the diaphragm for HIV prevention. We described reported contraceptive method use and calculated rates of pregnancy by contraceptive method. We compared time to first pregnancy by study arm (condoms or condoms plus diaphragm), and estimated a Cox proportional hazards model to identify predictors of pregnancy.

RESULTS

Condoms (25.8%), injectables (25.4%) and OC (21.6%) were the most commonly used methods; long-acting method use was rare. During the trial, 51.6% of women used the same method, 27.4% switched to a more effective method and 20.9% switched to a less effective method; 21.4% of women became pregnant. Pregnancy rates by contraceptive group mirrored published estimates; frequency of study product use was not associated with pregnancy.

CONCLUSION

Long-acting methods of contraception should be made available in HIV prevention trials and to women in Southern Africa.

Discontinuation of oral contraceptives and depot medroxyprogesterone acetate among women with and without HIV in Uganda, Zimbabwe and Thailand

BACKGROUND

We examined hormonal contraceptive (HC) discontinuation and factors associated with discontinuation among HIV-uninfected women and the effect of HIV diagnosis on subsequent contraceptive use.

STUDY DESIGN

We analyzed 4461 HIV-uninfected women from a prospective study of HC and HIV acquisition in Uganda, Zimbabwe and Thailand. Participants were ages 18-35 years, not pregnant, and using oral contraceptives (OCs) or injectable depot medroxyprogesterone acetate (DMPA) for at least 3 months before enrollment (median duration of OC and DMPA use before enrollment was 11.7 and 8.9 months, respectively). We compared the probability of OC and DMPA discontinuation using survival analysis and factors related to discontinuation using Cox regression. We also analyzed contraceptive patterns among 194 women who became infected with HIV.

RESULTS

Median duration of use after study enrollment was 15.6 months for OCs and 18.5 months for DMPA. Continuation rates for both methods were highest in Thailand. Factors associated with OC discontinuation included, nausea, breast tenderness, condom use, and no sex. Factors associated with DMPA discontinuation included young age, breast tenderness, nausea, irregular bleeding, high-risk sexual behaviors, partner risk, condom use, and no sex. Following an HIV diagnosis, 135 (98.5%) of 137 hormonal users continued HC and 14 (25%) of 57 nonusers began using HC.

CONCLUSIONS

Contraceptive continuation for OCs and DMPA was relatively high over 2 years. Young women, those reporting side effects, and those using condoms are more likely to discontinue and need ongoing contraceptive counseling. Many women receiving HIV-positive diagnoses desire effective contraception.

Social desirability bias in family planning studies: a neglected problem

Studies on family planning methods traditionally have relied on self-reports of unknown validity and reproducibility. Social desirability bias, a type of information bias, occurs when study participants respond inaccurately - but in ways that will be viewed favorably by others. Several lines of evidence reveal that this bias can be powerful in sexual matters, including reports of coitus, use of contraceptives and induced abortion. For example, studies using vaginal prostate-specific antigen testing reveal underreporting of unprotected coitus and overreporting of barrier contraceptive use. Medication Event Monitoring System studies, which electronically record the time of pill dispensing from a bottle or pack, indicate widespread exaggeration of adherence to pill-taking regimens, including oral contraceptives. Comparisons of provider data and self-reports of induced abortions reveal extensive underreporting of induced abortion. Reliance on self-reported data underestimates contraceptive efficacy. Although techniques to minimize this bias exist, they are infrequently used in family planning studies. Greater skepticism about self-reports and more objective means of documenting coitus and contraceptive use are needed if contraceptive efficacy is to be accurately measured.

Injectable contraception: what should the longest interval be for reinjections?

BACKGROUND

Progestin-only injectable contraceptives continue to gain in popularity, but uncertainty remains about pregnancy risk among women late for reinjection. The World Health Organization (WHO) recommends a "grace period" of 2 weeks after the scheduled 13-week reinjection. Beyond 2 weeks, however, many providers send late clients home to await menses.

STUDY DESIGN

A prospective cohort study in Uganda, Zimbabwe and Thailand followed users of depot-medroxyprogesterone acetate (DMPA) for up to 24 months. Users were tested for pregnancy at every reinjection, allowing analysis of pregnancy risk among late comers.

RESULTS

The analysis consists of 2290 participants contributing 13,608 DMPA intervals. The pregnancy risks per 100 women-years for "on time" [0.6; 95% confidence interval (CI), 0.33-0.92], "2-week grace" (0.0; 95% CI, 0.0-1.88) and "4-week grace" (0.4; 95% CI, 0.01-2.29) injections were low and virtually identical.

CONCLUSION

Extending the current WHO grace period for DMPA reinjection from 2 to 4 weeks does not increase pregnancy risk and could increase contraceptive continuation.