Oral contraceptive use and bone mineral density in premenopausal women:  cross-sectional, population-based data from the Canadian Multicentre Osteoporosis  Study

Jerilynn C Prior; Kirkland SA; Lawrence Joseph; Nancy Kreiger; Timothy M Murray; David A Hanley; Jonathan D Adachi; Y M Vigna; Claudie Berger; L Blondeau; Stuart A Jackson; Alan Tenenhouse

Bone Health · Bone Mineral Density

Oral contraceptive use and bone mineral density in premenopausal women: cross-sectional, population-based data from the Canadian Multicentre Osteoporosis Study

Prior JC, Kirkland SA, Joseph L, Kreiger N, Murray TM, Hanley DA, Adachi JD, Vigna YM, Berger C, Blondeau L, Jackson SA, Tenenhouse A

Published November 9, 2001 CMAJ : Canadian Medical Association Journal = Journal De l'Association Medicale Canadienne, 165(8), 1023-1029

PMID 11699697

Abstract

Background

Positive and negative effects on bone mineral density (BMD) have been described as a result of the premenopausal use of oral contraceptives (OCs); increased fracture rates have also been reported. This study assessed the relation between OC use and BMD in a population-based, 9-centre, national sample of women aged 25-45 years.

Methods

Premenopausal women who had been enrolled in the Canadian Multicentre Osteoporosis Study were classified as having ever been OC users (> or = 3 months) or as having never been OC users (0 to < 3 months). Data were obtained through extensive questionnaires and measuring of participants' weight, height and the BMD of lumbar vertebrae and the proximal femur.

Results

Of the sample of 524 women, whose mean age was 36.3 (standard deviation [SD] 5.9) years, 454 had used OCs; their mean age when they started using OCs was 19.8 (SD 3.5) years and the mean duration of use was 6.8 (SD 4.8) years. Women who had ever and those who had never used OCs showed no differences in age, age at menarche, parity, current calcium intake, exercise, body mass index (BMI), education, past irregular cycles or amenorrhea. OC users reported more alcohol and cigarette use and more use of medications to create regular cycles. Mean BMD values (adjusted for age, BMI and height) were 0.02-0.04 g/cm2 (that is, 2.3%-3.7%) lower in OC users, and were significantly lower in the spine and trochanter. The BMD of the spine in OC users was 1.03 (SD 0.12) g/cm2 versus 1.07 (SD 0.12) g/cm2 (95% confidence interval [CI] of difference -0.07 to -0.001) in those who had never used OCs. BMD was neither related to the duration of OC use nor to gynecological age at first use. Current and past users had similar BMD values.

Interpretation

National, population-based data show lower BMD values for the trochanter and spine in premenopausal women who have used OCs compared with those who have never used OCs.

Topics

By this author

Luteal Phase · Luteal Phase Deficiency

The influence of the menstrual cycle on muscle injuries - a systematic review and meta-analysis

Guthardt Y et al., 2026 Sci Rep Free full text on PubMed Central

This systematic review and meta-analysis examined the relationship between menstrual cycle phases and the incidence of muscle injuries in female team sport athletes, following PRISMA 2020 and PERSiST guidelines. A comprehensive search was conducted in PubMed, Scopus, and SPORTDiscus from inception to mid-January 2024. Studies were included if they examined female team sport athletes of reproductive age with regular menstrual cycles and compared the occurrence of muscle injuries across at least two menstrual phases. Studies involving hormonal contraceptive use, medications affecting the menstrual cycle or musculoskeletal system, or menstrual dysfunction were excluded. Three studies met the inclusion criteria, involving 318 participants. Meta-analysis yielded a pooled Risk Ratio of 1.18 (95% CI: 0.75 to 1.86, p = 0.46) for injury risk between the luteal and follicular phases, suggesting no statistically significant association. However, the certainty of the cumulative evidence was rated as very low due to methodological limitations, including inconsistent phase classifications and reliance on imprecise methods for identifying menstrual phases. Consequently, no practical or clinical recommendations can be made at this time. Future research employing standardised, physiologically accurate methods for classifying and detecting menstrual cycle phases is necessary to better understand the potential links between hormonal fluctuations and injury risk.

Breast Health · Benign Breast Conditions

MON-154 Breast areolar diameter in healthy menstruating women—a single cycle cross-sectional study of associations with body size and ovulatory characteristics

Baaske AV et al., 2025 Journal of the Endocrine Society Free full text on PubMed Central

Tanner Breast Stage 3 (TB3, at menarche) and Tanner 5 (TB5, once ovulatory cycles established), despite being similar with an “upstanding” nipple, are different. Evidence suggests that steady and high ovulatory-level progesterone exposure accounts for the larger areolar diameter in TB5. Progesterone levels indicate whether the menstrual cycle is ovulatory and have crucial implications for women’s reproductive, metabolic, cardiovascular, and bone health. However, few data show average areolar diameter in regularly cycling women in whom SES, body size, and reproductive variables have been documented. As a step towards better understanding the role of areolar diameter in reflecting estradiol-progesterone balance, this study aims to document the average mean bilateral lateral areolar diameter (AD) in a cohort of regularly menstruating, premenopausal women in whom ovulation was documented in one cycle. We also aim to describe relationships between AD and demographic, anthropometric, and reproductive/ovulation variables. Women were eligible if aged 19-35 years with about month-apart cycles and no exogenous hormone use in the last 3-months. Participants completed one cycle with a daily Menstrual Cycle Diary© (cycle length, CL) and first morning temperatures for Quantitative Basal Temperature© (QBT©) ovulation analysis (normal luteal phase length ≥10 days). Questionnaires gathered SES, ethnic, general health, and reproductive characteristics. Bilateral horizontal areolar diameters were measured by a woman researcher with the participant supine in a warm room. From February 2020 to September 2022 (during the SARS-CoV-2 pandemic), 73 women from Metro Vancouver, British Columbia participated. Women were of median (min-max) age 30 (19-35) years, BMI 24.5 (17.1-41.4) and most identified as White (61.6%) with a median of 16 years of education. Median CL was 29 days (n=65) and QBT data showed 39.3% were normally ovulatory, 34.4% had short luteal phases and 26.2% were anovulatory. Median within-woman bilateral AD was 3.85 (2.35-8.00) cm. Left AD exceeded right (L 3.8 [2.3,8.2]; R 3.7 [ 2.4,7.8]; P=.003). Larger AD (≥3.85cm) was associated with greater body size (BMI r=.534), weight and waist circumference. However, earlier age at menarche (P=.02) was also significantly associated. No other reproductive variables (cycle length, luteal phase length, parity, ever use of CHC) were related to AD before body size adjustments. This study is the first to document, and describe demographic, anthropomorphic and reproductive associations with, AD in community dwelling, regularly cycling, premenopausal women. Future steps will determine the most influential of the anthropometric variables; adjustment for these will facilitate assessments of associations with ovulation related characteristics.

Breast Health · Benign Breast Conditions

SAT-128 Prospective 1-year Menstrual CycleBreast Tenderness and Swelling Experiences—data from healthy regularly cycling women initially proven normally ovulatory on two consecutive cycles

Wood M et al., 2025 Journal of the Endocrine Society Free full text on PubMed Central

Breast tenderness and swelling are associated with premenstrual symptoms but have not been well described in healthy, normally cycling women with known ovulatory status. There are documented negative health risks (in bone, the cardiovascular system and cancers) in association with ovulatory disturbances within normal-length cycles. Identifying breast changes across a predictable, month-apart cycle but with Subclinical Ovulatory Disturbances (SOD, short luteal phase [<10 days] and anovulation (with normal estradiol but lower or absent progesterone levels) could advance our understanding of menstrual cycle physiology, women’s health education and identification of those with chronic SOD who may benefit from cyclic progesterone therapy. Our objective was to determine whether within-woman breast tenderness and swelling experiences differed between normally ovulatory and ovulatory-disturbed cycles. In this 1-year prospective observational study, we examined daily breast tenderness (0-4) and swelling (1-5 change from usual = 3) experiences recorded via the Menstrual Cycle Diary© over ≥8 cycles (mean=13/woman) in 53 women. Ovulatory status was documented by the twice-validated Quantitative Basal Temperature© (QBT©) analysis. Cycle and ovulatory data were previously reported (Prior NEJM, 1990); Diary data were unreported. Participants were healthy, community-dwelling women, mean age 34 (32.4:35.5 years), BMI 22.0, primarily White, and about two-thirds were runners (for health or were marathon-training). Comparison of breast parameters in all normally ovulatory (n = 495) vs all SOD cycles (n = 199) (mean cycle length 28.1 [27.5-28.8 days]), showed significantly higher Breast Tenderness Score [intensity X days; 6.0 (range 1.0, 14.0) vs. 3.0 (0.0, 11.0) (P = .001)] and increased breast size [4.0 (2.0, 4.0) vs. 4.0 (0.0, 4.0) (P = .034]) in normally ovulatory cycles. However, in within-woman analysis (n = 47 women with both normally ovulatory and SOD cycles), breast tenderness/swelling did not significantly differ by ovulatory status. We plotted all ovulatory cycles (n=676) centred on ovulation; this revealed parallel timing of increases in breast tenderness and swelling in the late luteal phase. These 1-year prospective data documented that mild breast tenderness and swelling occurred before flow in cycles with normal ovulation; symptoms were less in SOD cycles. Breast changes were totally absent during the follicular phases.

Hormonal Agents · Progesterone and Progestins

"SUN-109 Feasibility of Cyclic Progesterone and Spironolactone for PCOS-specific Health-Related Quality of Life—a six-month, Phase II, single arm, single center, open-label study"

Nelson K et al., 2025 J Endocr Soc Free full text on PubMed Central

Polycystic ovary syndrome (PCOS) is an endocrine-metabolic disorder that significantly decreases health-related quality of life (HRQoL). Combined hormonal contraceptives (CHC) are standard-of-care for PCOS but do not mitigate the neuroendocrine cause nor women’s primary concerns. Treatment options need expansion. We hypothesized cyclic oral micronized progesterone (CyclicP4) and spironolactone (Sp) would improve HRQoL, decrease LH, and acne. This Phase II, open-label single-arm pilot study evaluated the 6-month cyclicP4 and Sp treatment feasibility and safety in androgenic PCOS. Our primary outcome was within-woman change in PCOS-HRQoL (PCOSQ). No sample size calculation was possible; 40 was considered feasible. Eligible women were 19-40 years with physician-diagnosed androgenic PCOS. Exclusion criteria included HbA1c > 6.4%, use of metformin or CHC in the last month. Participants received progesterone (300 mg/bedtime 14 days/month); spironolactone (200 mg/day) began in cycle two. Adherence was tracked daily (Menstrual Cycle Diary©) and by pill counts. Safety was assessed by post-study potassium (K+). Feasibility by women’s post-trial treatment intention. PCOSQ, serum LH, calculated bioavailable testosterone (cBAT), HbA1c, hsCRP, and AMH were measured at baseline and trial end. We also assessed perceived acne and sleep changes (-5 to +5), K+ and therapy intent at study end. Six-month change by paired t-test or Wilcoxon signed-rank assessed P < .05 as important. Of 109 expressing interest, 41 enrolled, 36 began therapy (5 did not), and 26 provided final questionnaire data (19 with complete lab data). Completing women were mean age 29 (SD 4.9) years, BMI 30.3 (8.1), 61.5% White and 73.1% with university degrees. Total PCOSQ scores within-woman increased from 3.5±1.0 to 4.9±1.1 (95% CI 3.1-3.8, 4.6-5.3; P<.0000001). Each PCOSQ domain significantly improved (at least P<.001) as did acne and sleep. Weight was unchanged but waist circumference decreased 1.1 cm (NS). LH, cBAT, and AMH each decreased: LH 10.0±5.4 to 8.5±5.2 IU/L (95% CI 7.6-12.3, 6.3-10.8; P<.4), cBAT 0.7±0.4 to 0.6±0.3 nmol/L (0.5-0.9, 0.5-0.8; P<.2), and AMH 10.5±6.5 to 9.7±5.7 ng/ml (7.4-13.7, 7.0-12.4; P<.4). hsCRP remained unchanged (2.8±3.3 to 2.7±3.6 mg/L; P<.8) as did HbA1c (5.2±0.3 to 5.2±0.3%; P<.0). K+ remained within the normal range (3.5-5.0 mmol/L) at final testing (mean 4.0). Two allergic responses to spironolactone and one frequent flow/religious practice led to discontinuation. Feasibility was confirmed and participants strongly preferred continuing therapy (median Likert score=6/7, P<.0001) CyclicP4 and Sp for 6-months was feasible and significantly improved HRQoL in a non-medicine-seeking community women cohort with androgenic PCOS. Though the small sample size limited generalizability, findings are promising. A larger randomized trial comparing CyclicP4 vs. CHC is warranted.

Related research

Hormones and Bone · Contraceptive Effects on Bone

The association between oral contraceptive use, bone mineral density and fractures in women aged 50-80 years

Wei S et al., 2011 Contraception Free to read

The associations between oral contraceptive (OC) use, bone mineral density (BMD) and the risk of fractures remain controversial. A cross-sectional study of 491 women aged 50-80 years was performed. We assessed OC use and fractures by questionnaire, and BMD and vertebral deformity by dual-energy x-ray absorptiometry. Ever use of OC was associated with significantly higher BMD at the total body (6%, p<.001) and spine (4%; p=.05) (but not hip) after adjustment for confounders. There was also a significant association between duration of OC use and total body and spine BMD. Use of OCs for 5-10 years was associated with reduced vertebral deformity (adjusted odds ratio 0.46, 95% confidence interval 0.22-0.94). Oral contraceptive use and duration were associated with higher total body and spine BMD and a consistent reduction in vertebral deformities, although most associations did not reach significance.

Bone Mineral Density · Peak Bone Mass

Combined hormonal contraceptives use and bone mineral density changes in adolescent and young women in a prospective population-based Canada-wide observational study

Brajic TS et al., 2018 J Musculoskelet Neuronal Interact

To assess combined hormonal contraceptives (CHC) use and adolescent women's peak areal bone mineral density (BMD) accrual. We enrolled 527 randomly selected women across Canada (2004-6) divided by age into adolescents (16-19) and young adults (20-24) and by CHC use to ever (E-CHC)/never (N-CHC) users. At baseline and year 2 we measured height, weight, and BMD at lumbar spine (L1-4), femoral neck, and total hip sites. Interviewer-administered questionnaires addressed menarche age, cigarette and alcohol use, calcium/vitamin D intakes, physical activity and estrogen dose (≤30/>30 micrograms). Linear regression models examined associations of CHC use with 2-year BMD change adjusted for bone-related variables. Of 307 women with complete data, 229 (75%) used CHC. N-CHC adolescents gained significantly more unadjusted total hip BMD +0.012 g/cm(2)/2-y (95% C.I.: 0.001, 0.023) with similar trends at all sites. N-CHC adolescents tended to have greater adjusted femoral neck BMD gain: mean difference +0.009 g/cm(2) (95% CI: -0.002; 0.021). In young women N-CHC, however, adjusted femoral neck BMD decreased significantly more -0.021 g/cm(2) (95%CI: -0.006; -0.036) with similar trends at other sites. BMD changes were unrelated to estrogen dose and age at starting CHC. Adolescent CHC users in a random population demonstrated less hip region peak BMD accrual than non-users. This requires randomized control trial confirmation.

Fracture Risk · Risk Factors

Oral contraceptive use and risk of fractures

Vestergaard P et al., 2006 Contraception

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. 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. Oral contraceptives are not associated with an increase or a decrease in fracture risk. Any change in fracture risk may be due to confounders.

Fracture Risk · Risk Factors

Oral contraceptive pill use and fractures in women: a prospective study

Cooper C et al., 1993 Bone

It has been suggested that use of the oral contraceptive pill by women confers protection against osteoporosis later in life. However, cross-sectional studies of bone density among pill users have yielded discrepant results. We therefore investigated the relationship between pill use and subsequent occurrence of fracture in a cohort of 46,000 women enrolled in the Royal College of General Practitioners Oral Contraception Study during 482,083 person-years of follow-up. Fracture risk was lower among multiparous women, non-smokers, and those of lower socio-economic class. The risk of subsequent fractures among the women who had ever used the oral contraceptive pill was significantly greater than that among women who had never used it (relative risk 1.20, 95% confidence intervals 1.08-1.34) after adjustment for these variables. When the analysis was confined to forearm fractures, no significant effect of pill use on fracture risk was detected. Although the study only includes limited observation of older women to date, these data do not support the hypothesis that pill use protects women against the occurrence of osteoporotic fractures in later life.

Bone Health › Bone Mineral Density › Peak Bone Mass · Contraception › Oral Contraceptives › Metabolic Effects · Therapeutics › Hormonal Agents › Estrogen Preparations

Stuart A Jackson, Nancy Kreiger, Timothy M Murray, Jerilynn C Prior, Alan Tenenhouse

S Jackson, N Kreiger, Tim Murray, T Murray, J Prior, A Tenenhouse

PMID 11699697 11699697 Prior et al. 2001, Prior 2001

Cite this article

Prior, J. C., Kirkland, S. A., Joseph, L., Kreiger, N., Murray, T. M., Hanley, D. A., Adachi, J. D., Vigna, Y. M., Berger, C., Blondeau, L., Jackson, S. A., & Tenenhouse, A. (2001). Oral contraceptive use and bone mineral density in premenopausal women: cross-sectional, population-based data from the Canadian Multicentre Osteoporosis Study. CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne, 165(8), 1023-1029.

Keywords

Contraceptives, Oral