Oral contraceptives and back pain in women in a Swedish community.

BACKGROUND Female back pain is a clinical problem-especially low back pain with symptoms from the pelvic posterior region-that is often aggravated in connection with pregnancy and childbirth. Hormones have been suggested as an aetiologic factor. This study is aimed to determine whether additional hormone preparations, i.e. oral contraceptives (OC), may contribute to the increased frequency of such pain. METHODS A register study was conducted to investigate the use of drugs and health care use in a female population with known OC consumption. Specifically, we registered the number of primary health care visits for low back pain, comparing OC users with non-OC using age-matched women with otherwise equal circumstances. RESULTS OC users recorded a significantly higher incidence of low back symptoms during the study period compared to non-users. Pregnancy was not found to be a confounding factor. CONCLUSIONS The intriguing association between OC use and a higher incidence of low back pain, does not enable us to conclude that there is a causal connection, but it should lead to further studies.