Oral contraceptive use in perimenopause
Scholes D, LaCroix AZ, Hubbard RA, et al. Oral contraceptive use and fracture risk around the menopausal transition. Menopause. 2016;23(2):166-174.
The use of OCs in women of older reproductive age has increased ever since the cutoff age of 35 years was eliminated.4 Lower doses have continued to be utilized in these "older" women with excellent control of irregular bleeding due to ovulatory dysfunction (and reduction in psychosocial symptoms as well).5
The effect of OC use on risk of fracture remains unclear, and use during later reproductive life may be increasing. To determine the association between OC use during later reproductive life and risk of fracture across the menopausal transition, Scholes and colleagues conducted a population-based case-controlled study in a Pacific Northwest HMO, Group Health Cooperative.
Details of the study
Scholes and colleagues enrolled 1,204 case women aged 45 to 59 years with incident fractures, and 2,275 control women. Potential cases with fracture codes in automated data were adjudicated by electronic health record review. Potential control women without fracture codes were selected concurrently, sampling based on age. Participants received a structured study interview. Using logistic regression, associations between OC use and fracture risk were calculated as odds ratios (ORs) and 95% confidence intervals (CIs).
Participation was 69% for cases and 64% for controls. The study sample was 82% white; mean age was 54 years. The most common fracture site for cases was the wrist/forearm (32%). Adjusted fracture risk did not differ between cases and controls for OC use:
- in the 10 years before menopause (OR, 0.90; 95% CI, 0.74-1.11)
- after age 38 years (OR, 0.94; 95% CI, 0.78-1.14)
- over the duration, or
- for other OC exposures.
Related article:
2016 Update on female sexual dysfunction
Association between fractures and OC use near menopause
The current study does not show an association between fractures near the menopausal transition and OC use in the decade before menopause or after age 38 years. For women considering OC use at these times, fracture risk does not seem to be either reduced or increased.
These results, looking at fracture, seem to be further supported by trials conducted by Gambacciani and colleagues,6 in which researchers randomly assigned irregularly cycling perimenopausal women (aged 40-49 years) to 20 μg ethinyl estradiol OCs or calcium/placebo. Results showed that this low-dose OC use significantly increased bone density at the femoral neck, spine, and other sites relative to control women after 24 months.
In the current Scholes study, the use of OCs in the decade before menopause or after age 38 did not reduce fracture risk in the years around the time of menopause. It is reassuring that their use was not associated with any increased fracture risk.
WHAT THIS EVIDENCE MEANS FOR PRACTICE
These findings provide additional clarity and guidance to women and their clinicians at a time of increasing public health concern about fractures. For women who may choose to use OCs during late premenopause (around age 38-48 years), fracture risk around the menopausal transition will not differ from women not choosing this option.
These findings provide additional clarity and guidance to women and their clinicians at a time of increasing public health concern about fractures. For women who may choose to use OCs during late premenopause (around age 38-48 years), fracture risk around the menopausal transition will not differ from women not choosing this option.