Daily Progestogen for Contraception: A Clinical Study

Abstract

Chlormadinone acetate, one tablet (0.5 mg.) daily, was given without interruption to two groups of fertile women, 945 non-lactating and 100 lactating, for contraception, for a total of 8,652 months. Conception was successfully prevented without inhibiting ovulation, and with endogenous hormonal control of cycle bleeding. Whereas endometrial suppression and inhibition of cervical mucus demonstrated the anti-oestrogenic property of the progestogen, the degree of fertility protection cannot be explained solely on these mechanisms. Chlormadinone acetate provides contraception during the lactation period and was not found to interfere with nursing needs. Other than bleeding irregularities, which may be overcome by using still lower dosage, chlormadinone acetate was found to be remarkably benign. © 1967, British Medical Journal Publishing Group. All rights reserved.