Progestin-only contraceptives (POCs) are appropriate for many women who cannot or should not take estrogen. POCs include injectables, intrauterine contraception, implants, and oral contraceptives. Many POCs are long-acting, cost-effective methods of preventing pregnancy. However, concern about weight gain can deter the initiation of contraceptives and cause early discontinuation among users.
Objectives
The primary objective was to evaluate the association between progestin-only contraceptive use and changes in body weight.
Search Methods
Until 4 August 2016, we searched MEDLINE, CENTRAL, POPLINE, LILACS, ClinicalTrials.gov, and ICTRP. For the initial review, we contacted investigators to identify other trials.
Selection Criteria
We considered comparative studies that examined a POC versus another contraceptive method or no contraceptive. The primary outcome was mean change in body weight or mean change in body composition. We also considered the dichotomous outcome of loss or gain of a specified amount of weight.
Data Collection and Analysis
Two authors extracted the data. Non-randomized studies (NRS) need to control for confounding factors. We used adjusted measures for the primary effects in NRS or the results of matched analysis from paired samples. If the report did not provide adjusted measures for the primary analysis, we used unadjusted outcomes. For RCTs and NRS without adjusted measures, we computed the mean difference (MD) with 95% confidence interval (CI) for continuous variables. For dichotomous outcomes, we calculated the Mantel-Haenszel odds ratio (OR) with 95% CI.
Main Results
We found 22 eligible studies that included a total of 11,450 women. With 6 NRS added to this update, the review includes 17 NRS and 5 RCTs. By contraceptive method, the review has 16 studies of depot medroxyprogesterone acetate (DMPA), 4 of levonorgestrel-releasing intrauterine contraception (LNG-IUC), 5 for implants, and 2 for progestin-only pills.Comparison groups did not differ significantly for weight change or other body composition measure in 15 studies. Five studies with moderate or low quality evidence showed differences between study arms. Two studies of a six-rod implant also indicated some differences, but the evidence was low quality.Three studies showed differences for DMPA users compared with women not using a hormonal method. In a retrospective study, weight gain (kg) was greater for DMPA versus copper (Cu) IUC in years one (MD 2.28, 95% CI 1.79 to 2.77), two (MD 2.71, 95% CI 2.12 to 3.30), and three (MD 3.17, 95% CI 2.51 to 3.83). A prospective study showed adolescents using DMPA had a greater increase in body fat (%) compared with a group not using a hormonal method (MD 11.00, 95% CI 2.64 to 19.36). The DMPA group also had a greater decrease in lean body mass (%) (MD -4.00, 95% CI -6.93 to -1.07). A more recent retrospective study reported greater mean increases with use of DMPA versus Cu IUC for weight (kg) at years 1 (1.3 vs 0.2), 4 (3.5 vs 1.9), and 10 (6.6 vs 4.9).Two studies reported a greater mean increase in body fat mass (%) for POC users versus women not using a hormonal method. The method was LNG-IUC in two studies (reported means 2.5 versus -1.3; P = 0.029); (MD 1.60, 95% CI 0.45 to 2.75). One also studied a desogestrel-containing pill (MD 3.30, 95% CI 2.08 to 4.52). Both studies showed a greater decrease in lean body mass among POC users. AUTHORS'
Conclusions
We considered the overall quality of evidence to be low; more than half of the studies had low quality evidence. The main reasons for downgrading were lack of randomizations (NRS) and high loss to follow-up or early discontinuation.These 22 studies showed limited evidence of change in weight or body composition with use of POCs. Mean weight gain at 6 or 12 months was less than 2 kg (4.4 lb) for most studies. Those with multiyear data showed mean weight change was approximately twice as much at two to four years than at one year, but generally the study groups did not differ significantly. Appropriate counseling about typical weight gain may help reduce discontinuation of contraceptives due to perceptions of weight gain.
progestin-only contraceptives weight gain, DMPA weight change evidence, levonorgestrel IUD weight effects, implant contraceptive weight, progestin oral contraceptive body weight, Cochrane review POC weight, injectable contraceptive weight gain, hormonal contraception body composition, etonogestrel implant weight, contraceptive discontinuation weight concern
PMID 27567593 27567593 DOI 10.1002/14651858.CD008815.pub4 10.1002/14651858.CD008815.pub4
Cite this article
Lopez, L. M., Ramesh, S., Chen, M., Edelman, A., Otterness, C., Trussell, J., & Helmerhorst, F. M. (2016). Progestin-only contraceptives: effects on weight. The Cochrane database of systematic reviews, 2016(8), CD008815. https://doi.org/10.1002/14651858.CD008815.pub4
Lopez LM, Ramesh S, Chen M, Edelman A, Otterness C, Trussell J, et al. Progestin-only contraceptives: effects on weight. Cochrane Database Syst Rev. 2016;2016(8):CD008815. doi:10.1002/14651858.CD008815.pub4
Lopez, L. M., et al. "Progestin-only contraceptives: effects on weight." The Cochrane database of systematic reviews, vol. 2016, no. 8, 2016, pp. CD008815.
Keywords
Contraceptives, Oral, Hormonal, Drug Implants, Progestins, Levonorgestrel, Medroxyprogesterone Acetate
Weight gain is often considered a side effect of combination hormonal contraceptives, and many women and clinicians believe that an association exists. Concern about weight gain can limit the use of this highly effective method of contraception by deterring the initiation of its use and causing early discontinuation among users. However, a causal relationship between combination contraceptives and weight gain has not been established. The aim of the review was to evaluate the potential association between combination contraceptive use and changes in weight. In November 2013, we searched the computerized databases CENTRAL (The Cochrane Library), MEDLINE, POPLINE, EMBASE, and LILACS for studies of combination contraceptives, as well as ClinicalTrials.gov and International Clinical Trials Registry Platform (ICTRP). For the initial review, we also wrote to known investigators and manufacturers to request information about other published or unpublished trials not discovered in our search.
All English-language, randomized controlled trials were eligible if they had at least three treatment cycles and compared a combination contraceptive to a placebo or to a combination contraceptive that differed in drug, dosage, regimen, or study length.
All titles and abstracts located in the literature searches were assessed. Data were entered and analyzed with RevMan. A second author verified the data entered. For continuous data, we calculated the mean difference and 95% confidence interval (CI) for the mean change in weight between baseline and post-treatment measurements using a fixed-effect model. For categorical data, such as the proportion of women who gained or lost more than a specified amount of weight, the Peto odds ratio with 95% CI was calculated. We found 49 trials that met our inclusion criteria. The trials included 85 weight change comparisons for 52 distinct contraceptive pairs (or placebos). The four trials with a placebo or no intervention group did not find evidence supporting a causal association between combination oral contraceptives or a combination skin patch and weight change. Most comparisons of different combination contraceptives showed no substantial difference in weight. In addition, discontinuation of combination contraceptives because of weight change did not differ between groups where this was studied. AUTHORS' Available evidence was insufficient to determine the effect of combination contraceptives on weight, but no large effect was evident. Trials to evaluate the link between combination contraceptives and weight change require a placebo or non-hormonal group to control for other factors, including changes in weight over time.
Age-related decline in bone mass increases the risk of skeletal fractures, especially those of the hip, spine, and wrist. Steroidal contraceptives have been associated with changes in bone mineral density in women. Whether such changes affect the risk of fractures later in life is unclear. Hormonal contraceptives are among the most effective and most widely-used contraceptives. Concern about fractures may limit the use of these effective contraceptives. Observational studies can collect data on premenopausal contraceptive use as well as fracture incidence later in life. We systematically reviewed the evidence from observational studies of hormonal contraceptive use for contraception and the risk of fracture in women. Through June 2015, we searched for observational studies. The databases included PubMed, POPLINE, Cochrane Central Register of Controlled Trials (CENTRAL), LILACS, EMBASE, CINAHL, and Web of Science. We also searched for recent clinical trials through ClinicalTrials.gov and the ICTRP. For other studies, we examined reference lists of relevant articles and wrote to investigators for additional reports.
We included cohort and case-control studies of hormonal contraceptive use. Interventions included comparisons of a hormonal contraceptive with a non-hormonal contraceptive, no contraceptive, or another hormonal contraceptive. The primary outcome was the risk of fracture.
Two authors independently extracted the data. One author entered the data into RevMan, and a second author verified accuracy. We examined the quality of evidence using the Newcastle-Ottawa Quality Assessment Scale (NOS), developed for case-control and cohort studies. Sensitivity analysis included studies of moderate or high quality based on our assessment with the NOS.Given the need to control for confounding factors in observational studies, we used adjusted estimates from the models as reported by the authors. Where we did not have adjusted analyses, we calculated the odds ratio (OR) with 95% confidence interval (CI). Due to varied study designs, we did not conduct meta-analysis. We included 14 studies (7 case-control and 7 cohort studies). These examined oral contraceptives (OCs), depot medroxyprogesterone acetate (DMPA), and the hormonal intrauterine device (IUD). This section focuses on the sensitivity analysis with six studies that provided moderate or high quality evidence.All six studies examined oral contraceptive use. We noted few associations with fracture risk. One cohort study reported OC ever-users had increased risk for all fractures (RR 1.20, 95% CI 1.08 to 1.34). However, a case-control study with later data from a subset reported no association except for those with 10 years or more since use (OR 1.55, 95% CI 1.03 to 2.33). Another case-control study reported increased risk only for those who had 10 or more prescriptions (OR 1.09, 95% CI 1.03 to 1.16). A cohort study of postmenopausal women found no increased fracture risk for OC use after excluding women with prior fracture. Two other studies found little evidence of association between OC use and fracture risk. A cohort study noted increased risk for subgroups, such as those with longer use or specific intervals since use. A case-control study reported increased risk for any fracture only among young women with less than average use.Two case-control studies also examined progestin-only contraceptives. One reported increased fracture risk for DMPA ever-use (OR 1.44, 95% CI 1.01 to 2.06), more than four years of use (OR 2.16, 95% CI 1.32 to 3.53), and women over 50 years old. The other reported increased risk for any past use, including one or two prescriptions (OR 1.17, 95% CI 1.07 to 1.29) and for current use of 3 to 9 prescriptions (OR 1.36, 95% CI 1.15 to 1.60) or 10 or more (OR 1.54, 95% CI 1.33 to 1.78). For the levonorgestrel-releasing IUD, one study reported reduced fracture risk for ever-use (OR 0.75, 95% CI 0.64 to 0.87) and for longer use. AUTHORS' Observational studies do not indicate an overall association between oral contraceptive use and fracture risk. Some reported increased risk for specific user subgroups. DMPA users may have an increased fracture risk. One study indicated hormonal IUD use may be associated with decreased risk. Observational studies need adjusted analysis because the comparison groups usually differ. Investigators should be clear about the variables examined in multivariate analysis.
Concerns about weight gain may influence contraceptive use. We compared the change in body weight over the first 12 months of use between women using the etonogestrel (ENG) implant, the levonorgestrel intrauterine system (LNG-IUS) or depot medroxyprogesterone acetate (DMPA) with women using the copper intrauterine device (IUD). This was a substudy of the Contraceptive CHOICE Project, a prospective cohort study of 9256 women provided no-cost contraception. Women who had been using the ENG implant, LNG-IUS, DMPA or copper IUD continuously for at least 11 months were eligible for participation. We obtained body weight at enrollment and at 12 months and compared the weight change for each progestin-only method to the copper IUD. We enrolled a total of 427 130 ENG implant users, 130 LNG-IUS users, 67 DMPA users and 100 copper IUD users. The mean weight change (in kilograms) over 12 months was 2.1 for ENG implant users [standard deviation (SD)=6.7]; 1.0 for LNG-IUS users (SD=5.3); 2.2 for DMPA users (SD=4.9) and 0.2 for copper IUD users (SD=5.1). The range of weight change was broad across all contraceptive methods. In the unadjusted linear regression model, ENG implant and DMPA use were associated with weight gain compared to the copper IUD. However, in the adjusted model, no difference in weight gain with the ENG implant, LNG-IUS or DMPA was observed. Only Black race was associated with significant weight gain (1.3 kg, 95% confidence interval=0.2-2.4) when compared to other racial groups. Weight change was variable among women using progestin-only contraceptives. Black race was a significant predictor of weight gain among contraceptive users.
"Fertility awareness-based methods" (FAB) of family planning "involve identification of the fertile days of the menstrual cycle, whether by observing fertility signs such as cervical secretions and basal body temperature, or by monitoring cycle days. FAB methods can be used in combination with abstinence or barrier methods during the fertile time" (WHO 2000). Several names have been used to describe this approach to contraception, including "rhythm," "natural family planning" and "periodic abstinence." Fertility awareness-based methods can be used with abstinence from sexual intercourse. Alternatively, they can be used with barrier contraceptives or withdrawal during presumed fertile times. We retrieved and analyzed all randomized controlled trials that examined any fertility awareness-based methods used for contraception. We searched the computerized databases Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, POPLINE, EMBASE, and LILACS (each from its inception to January, 2004) for randomized controlled trials of fertility awareness-based methods. We examined the reference list of each trial as well as that of review articles.
We included all randomized controlled trials in any language that compared any fertility awareness-based methods for contraception with a placebo; another method, including an alternative fertility awareness-based method; or fertility awareness-based methods used in conjunction with another contraceptive. We assessed all titles and abstracts found for inclusion. We evaluated the methodological quality of the trials for potential biases by qualitatively assessing the study design; randomization method; allocation concealment; blinding; premature discontinuation rates; and loss to follow-up rates. Because of methodological weaknesses, we could not enter the trial results in RevMan, calculate measures of association, or aggregate data. Because of poor methods and reporting, pregnancy rates could not be determined. A trial in Colombia found similar numbers of pregnancies among women randomized to the ovulation and symptothermal methods. In contrast, a companion trial in Los Angeles observed more pregnancies in the group assigned to the ovulation method. In the two U.S. trials, recruitment of participants was unexpectedly difficult; this aspect was not mentioned in the report from Colombia. Continuation rates were poor. In the two larger trials, most participants discontinued their assigned method before entering the observation phase of the trial. REVIEWERS' The comparative efficacy of fertility awareness-based methods of contraception remains unknown. Despite intensive training and ongoing support, most participants in these trials discontinued prematurely. Contraceptive methods should be properly evaluated, preferably in randomized controlled trials, before adoption and dissemination.