The present work investigated the effects of Norplant implants on the pituitary-adrenal function among 15 users of Norplant implants prior to and 6 months after insertion of the implants. Serum cortisol levels and their diurnal variations, ACTH and 24-h urinary 17-ketosteroids, ketogenic steroids, 17-hydroxy steroids, and creatinine, were measured. Also, a dynamic test (the 5-h Synacthen depot = ACTH stimulation test) was done before and 6 months after implants insertion. The 9 a.m. cortisol levels were blunted (within the normal ranges) while the 6 p.m. values were unaltered. The 24-h urinary ketogenic, hydroxy, and ketosteroids were also unchanged after Norplant implants use. The ACTH stimulation test showed a decreased adrenal response which was also within normal ranges. These data should raise the question related to suprarenal response to acute or prolonged stresses, such as surgical operations or shock in women using Norplant implants.
PIP: To ensure that Norplant contraceptive implants are not associated with a risk of pituitary-adrenal suppression, a series of laboratory tests were conducted in 15 women both before and 6 months after Norplant insertion. Comparisons of hormonal profiles before and after Norplant insertion revealed a significant drop in morning serum cortisol levels (404.33 +or- 84.07 nmol/l vs. 353.67 +or- 56.65 nmol/l, p 0.05), but no significant change in evening readings. The observed changes in morning cortisol values were still within the normal range. Serum ACTH values and 24-hour urinary 17-hydroxy steroids, 17-ketogenic steroids, and 17-ketosteroids were not different after insertion compared to baseline. Before Norplant insertion, injection of synthetic ACTH resulted in a 259.59 +or- 169.53% increase in the mean level of serum cortisol 5 hours later; 6 months after Norplant insertion, the percent rise above baseline was 165.85 +or- 91.64%. The significantly lower adrenal response among Norplant users (although still within normal limits) is presumably due to a local inhibition of the adrenal itself and not of the hypothalamic-pituitary axis. Although these findings suggest a minimal suppressive effect of prolonged microdose release of levonorgestrel from Norplant implants, the suprarenal response to acute or prolonged stresses (e.g., surgical operations or shock) in Norplant users requires investigation.