Antifertility Effect of Continuous Low-dosage Oral Progestogen Therapy

Abstract

Chlormadinone acetate 0.5 mg. was given daily as a continuous “ non-stop ” oral contraceptive to 390 young fertile healthy women during 3,400 months. Tolerance was good, systemic side-effects being infrequent. Uterine bleeding, menstrual cycle disturbances, and amenorrhoea were the main complaints against the method, but were seldom severe. In 47 women accessory oral oestrogen therapy was added to the daily progestogen to correct these alterations. The method can be started at any time after parturition or abortion ; it doe” not interfere with lactation. Its use is simple and does not require complicated instructions. The method seldom interferes with ovulation. In a few of the 12 subjects who underwent surgery while under therapy, fresh corpora lutea were observed. Urinary excretion of pregnanediol also indicated progesterone secretion. Studies have suggested possible interference with sperm ascent. No sperms have been recovered from the fluid flushing from Fallopian tubes obtained a few hours after coitus. Fertility is re-established immediately after therapy is discontinued, either in the first or the second cycle. Twenty-four undesired pregnancies have been observed during this period. They were due to improper use of the method in 11 women ; in 13 subjects who claim they used the method correctly apparently the method failed. The method is well tolerated and accepted by subjects who had experienced previous intolerance to conventional oral combined or sequential therapy. Its low cost and ease of administration makes it of interest to developing countries with limited resources for family planning. © 1968, British Medical Journal Publishing Group. All rights reserved.