Effects of continuous daily administration of 0.1 mg of norethindrone on the plasma levels of progesterone and on the urinary excretion of luteinizing hormone and total oestrogens.

Abstract

ABSTRACT Daily determinations of the plasma level of progesterone and the urinary excretion of LH and oestrogens were performed in four women during one control cycle followed by three months of daily treatment with 0.1 mg of norethindrone. According to the plasma progesterone pattern, all four women seemed to ovulate during their control cycle. Two women became pregnant during their second cycle of treatment. During treatment all four women showed an atypical LH pattern without any distinct midcycle peak. The mean LH excretion during treatment was not significantly different from the mean level of follicular phase of normal cycles. The oestrogens and progesterone levels were within normal ranges. It is concluded that during treatment with 0.1 mg of norethindrone daily an apparently normal pregnancy may occur in spite of a different LH excretion pattern.