Abstract
Serum LH levels were measured by a radioimmunoassay technique throughout the menstrual
cycle in 17 untreated healthy women, 19 women on norethindrone enanthate (200 mg intramuscularly
every 12 weeks) and 10 women receiving a continuous dose of 0.03 mg d-norgestrel daily.
All the controls showed a midcycle peak which represented a 4.0 to 16.3-fold increase
of the values observed during the proliferative phase. During the first four weeks
after injection of norethindrone enanthate LH levels were depressed. Small midcycle
rises were observed in only 2 cases. They represented 4.4 and 8.8-fold increase of
the basal LH concentration. From the 4th to the 12th week a progressive increase in
LH values was observed. During the last month of treatment the LH concentration was
even higher than in the controls, with the presence of moderated midcycle peaks. In
the d-norgestrel group, 9 of 10 subjects showed significant but diverse LH rises.
LH peaks in these women appeared earlier than in controls, the length of the menstrual
cycle was also shorter. During the first and second part of the cycle women on d-norgestrel
have significantly higher values than controls but the maximum midcycle elevations
were less pronounced.
Key words
Luteinizing Hormone - Radioimmunoassay - Progestagens - Contraception
1 Supported by a grant from Schering AG Berlin.
