Prior studies have suggested that oral contraceptives (OCs) may be associated with an increased fracture risk. However, the previous studies have only performed a limited adjustment for other potential risk factors.
Subjects and methodsAll women with a fracture (n=64,548) in the year 2000 in Denmark served as cases. For each case, three age-matched controls were randomly drawn from the general population (n=193,641). Exposure was use of OCs between January 1, 1996, and December 31, 2000. Adjustments were made for use of other drugs, pregnancy, prior fracture, other diseases and social variables.
Results
In the unadjusted analysis, use of OCs in low dose was associated with a small increase in overall fracture risk. However, upon adjustment, no increase in fracture risk could be demonstrated in any age or dose group.
Conclusion
Oral contraceptives are not associated with an increase or a decrease in fracture risk. Any change in fracture risk may be due to confounders.
oral contraceptive use fracture risk population study, oral contraceptives bone mineral density fracture risk, Vestergaard Rejnmark Mosekilde OC fracture Denmark, combined oral contraceptives skeletal effects case control, oral contraceptive dose fracture risk age groups, hormonal contraception bone health fracture confounders, low dose oral contraceptives fracture risk adjusted analysis, estrogen progestin contraceptive bone fracture population study, oral contraceptive use young women bone health fracture, Danish population case control study fracture oral contraceptives
PMID 16730486 16730486 DOI 10.1016/j.contraception.2006.01.006 10.1016/j.contraception.2006.01.006
Cite this article
Vestergaard, P., Rejnmark, L., & Mosekilde, L. (2006). Oral contraceptive use and risk of fractures. Contraception, 73(6), 571-576. https://doi.org/10.1016/j.contraception.2006.01.006
Vestergaard P, Rejnmark L, Mosekilde L. Oral contraceptive use and risk of fractures. Contraception. 2006;73(6):571-576. doi:10.1016/j.contraception.2006.01.006
Vestergaard, P., et al. "Oral contraceptive use and risk of fractures." Contraception, vol. 73, no. 6, 2006, pp. 571-576.
Epidemiological studies indicate a protective effect of postmenopausal oestrogen therapy on the risk of osteoporotic fractures. Whether premenopausal oestrogen exposure in the form of oral contraceptives also reduces the risk of osteoporotic fractures remains uncertain. We did a population-based case control study of hip fracture among Swedish postmenopausal women, 50-81 years of age, through mailed questionnaires and telephone interviews. Of those women who were eligible, 1327 (82.5%) cases and 3312 (81.6%) randomly selected controls responded. 130 (11.6%) cases and 562 (19.1%) controls reported ever-use of oral contraceptives. Ever-use of oral contraceptives was associated with a 25% reduction in hip fracture risk (odds ratio 0.75 [95% CI 0.59-0.96]). Women who had ever used a high-dose pill (equivalent to > or = 50 microg ethinylestradiol per tablet) had a 44% lower risk for hip fracture than never-users (0.56 [0.42-0.75]). No overall trend was observed with duration of oral-contraceptive use, or time since last use. However, when making comparisons with women who have never used oral contraceptives, the odds ratios for hip-fracture were 0.69 (0.51-0.94) for use after age 40, 0.82 (0.57-1.16) for use at ages 30-39, and 1.26 (0.76-2.09) for use before age 30. Our results imply that in postmenopausal women, oral-contraceptive use late in reproductive life may reduce the risk of hip fracture, although we recognise the limitations of the case-control method.
Contraception/ComparisonAdverse EventsCopper vs HormonalDevice Complications
To examine trends in national reporting of broken intrauterine devices (IUDs). We enumerated IUD device "breakage" reports in the Food and Drug Administration Adverse Event Reporting System from inception (1998) until February 2022. We explored associations of breakage with IUD type (copper versus hormonal), year reported, reporter (consumer versus clinician), and patient characteristics (age and weight). We identified 4144 breakage reports for copper versus 2140 for hormonal IUDs. Among the 170,215 adverse events reported, breaks were disproportionately reported for copper (9.6%) versus hormonal (1.7%) IUDs. National pharmacovigilance data suggests disproportionate breakage in copper versus hormonal IUDs though the true prevalence of breaks cannot be calculated from this dataset.
Contraception/ComparisonEfficacyNovel FormulationsPooled Analysis
Open Access
To evaluate overall and subgroup efficacy of an estetrol (E4) 15 mg drospirenone (DRSP) 3 mg oral contraceptive in a 24/4-day regimen. We pooled efficacy outcomes from 2 pivotal phase 3 contraceptive trials with E4/DRSP conducted in the United States/Canada and Europe/Russia. We assessed Pearl Index (PI; pregnancies per 100 participant-years) and 13-cycle life-table pregnancy rates in at-risk cycles (confirmed intercourse and no other contraceptive use) among participants 16 to 35 years. We calculated PI by age and further subcategorization (contraceptive history and body mass index [BMI]). We performed multivariable analysis using Cox regression to assess impact of potential confounding factors. Analyses included 3027 participants, of whom 451 (14.9%) had a BMI ≥30 kg/m(2). The pooled PI was 1.52 (95% confidence interval 1.04-2.16) and the 13-cycle life-table pregnancy rate was 1.28% (0.83%-1.73%). We calculated unadjusted pooled PI in participants 16 to 25 years and 26 to 35 years of 1.61 (0.94-2.57) and 1.43 (0.78-2.40), respectively; in new starters and switchers of 1.88 (1.09-3.00) and 1.24 (0.68-2.08), respectively; and by BMI <25 kg/m(2), 25 to 29.9 kg/m(2), and ≥30 kg/m(2) of 1.14 (0.64-1.88), 2.19 (1.05-4.03), and 2.27 (0.83-4.94), respectively. In multivariable analysis, we found associations of prior pregnancy (hazard ratio [HR] 3.61[1.56-8.38]), Black race (HR 4.61[1.97-10.80]), age 16 to 25 years (HR 2.37[1.09-5.15]) and compliance <99% of expected pills (HR 4.21[2.04-8.66]) with conception. E4/DRSP is an effective oral contraceptive overall and across subgroups stratified by age, contraceptive history, and BMI. Other than compliance, predictors of contraceptive failure are nonmodifiable. Pooled results from two phase 3 trials demonstrate high contraceptive efficacy of the novel estetrol-drospirenone oral contraceptive. Several non-modifiable risk factors, including prior pregnancy, race, and age, are associated with higher pregnancy risk. Additional research is needed to better understand predictors of combined oral contraceptive failure.
Fertility AwarenessApp ComparisonFertile Window IdentificationBBT and Cervical Mucus
The Natural Cycles app employs daily basal body temperature to define the fertile window via a proprietary algorithm and is clinically established effective in preventing pregnancy. We sought to (1) compare the app-defined fertile window of Natural Cycles to that of CycleProGo, an app that uses BBT and cervical mucus to define the fertile window and (2) compare the app-defined fertile windows to the estimated physiologic fertile window. Daily BBT were entered into Natural Cycles from 20 randomly selected regularly cycling women with at least 12 complete cycles from the CycleProGo database. The proportion of cycles with equivalent (±1 cycle day) fertile-window starts and fertile-window ends was determined. The app-defined fertile windows were then compared to the estimated physiologic fertile window using Peak mucus to estimate ovulation. Fifty seven percent of cycles (136/238) had equivalent fertile-window starts and 36% (72/181) had equivalent fertile-window end days. The mean overall fertile-window length from Natural Cycles was 12.8 days compared to 15.1 days for CycleProGo (p < 0.001). The Natural Cycles algorithm declared 12% to 30% of cycles with a fertile-window start and 13% to 38% of cycles with a fertile-window end within the estimated physiologic fertile window. The CycleProGo algorithm declared 4% to 14% of cycles with a fertile-window start and no cycles with a fertile-window end within the estimated physiologic fertile window. Natural Cycles designated a higher proportion of cycles days as infertile within the estimated physiologic fertile window than CycleProGo.
Use of cervical mucus in addition to BBT may improve the accuracy of identifying the fertile window. Additional studies with other markers of ovulation and the fertile window would give additional insight into the clinical implications of app-defined fertile window differences.