ORAL-CONTRACEPTIVES, PREGNANCY, AND ENDOGENOUS ESTROGEN IN GALL STONE DISEASE - A CASE-CONTROL STUDY

A case-control study of gall stone disease in women in relation to use of contraceptives, reproductive history and concentrations of endogenous hormones was undertaken. The study population comprised 200 hospital patients with newly diagnosed gall stone disease, 182 individually matched controls selected from the community and 234 controls who were patients in hospital. Use of oral contraceptives was associated with an increased risk of developing gall stones among young subjects but a decreased risk among older subjects. The risk of developing gall stone disease increased in association with increasing parity, particularly among younger women. The risk fell with increasing age at 1st pregnancy, independent of parity. Mean urinary excretion over 24 h of estrone, but not of pregnanediol, was significantly (P > 0.05) greater for postmenopausal patients than controls. The age dependence of the relative risk associated with exposure to oral contraceptives and pregnancy suggests that there are subpopulations of women susceptible to early formation of gall stones after exposure to either oral contraceptives or pregnancy.