Long-term exposure to progestin-only oral contraceptives or to a progestin intrauterine device is associated with a small beneficial effect on pelvic girdle pain, according to results from a prospective population-based cohort study published in The Cochrane Database of Systematic Reviews.1
Investigators used patient data from the Norwegian Mother and Child Cohort Study to evaluate persistent pelvic girdle pain approximately 18 months after delivery among women with a history of long-term exposure to progestin-only contraceptives. A total of 2071 patients (10.1%) in the cohort reported pelvic girdle pain 18 months after delivery.
Researchers found that long-term exposure (>12 months) of a progestin intrauterine device correlated with a lower incidence of persistent pelvic girdle pain (adjusted odds ratio [OR], 0.83; 95% CI, 0.72 ± 0.96; Ptrend =.021).
In addition, long-term exposure to progestin-only oral contraceptives was associated with reduced rates of reported pain (Ptrend =.005). A mildly significant increase in the odds of persistent pelvic girdle pain among women exposed to long-term progestin injections and/or a progestin implant was also observed (Ptrend =.046).
The 18-month postdelivery outcome of pelvic girdle pain was primarily based on patient reports, and the lack of clinical assessment for this outcome “may have biased the estimates towards the null.” In addition, the Norwegian Mother and Child Cohort study provides no data on postpregnancy progestin contraceptive use. Depending solely on these records, according to investigators, might have resulted in poor categorization of exposure.
Considering that progestin injections may have an impact on bone mineral density,2 investigators suggest that future research should focus on the “possible interactions between exposure to progestin injections and lactation regarding musculoskeletal health.”