Skip to main content
NCBI home page
British Medical Journal logoLink to British Medical Journal
. 1972 Jul 22;3(5820):195–200. doi: 10.1136/bmj.3.5820.195

Clinical and Laboratory Findings in a Trial of Norgestrel, a Low-dose Progestogen-only Contraceptive

P Eckstein, Margaret Whitby, K Fotherby, Christine Butler, T K Mukherjee, J B C Burnett, D J Richards, T P Whitehead
PMCID: PMC1785652  PMID: 4557273

Abstract

Norgestrel, a progestogen-only oral contraceptive, was given continually at a dose of 75 μg/day to 144 women of proved fertility. It was an efficient contraceptive with a failure rate of 2·1% (assessed by the “life-table” method) within the first 12 cycles and 3·6% within the first 30 cycles (or 2·0 conceptions per 100 woman-years when assessed by the Pearl index). The overall conception rate for the entire trial period was 2·1% and 1·3 pregnancies per 100 woman-years respectively. Norgestrel caused a high proportion of irregular and generally short bleeding intervals, about one-fifth of the cycles lasting less than 17 days. This irregularity appeared to be due to individual variance in cycle length between women rather than that between their successive cycles. No confirmed instances of thromboembolism were observed. Norgestrel apparently exerts its contraceptive action by several mechanisms: reduction in the sperm penetrability of the cervical mucus and an impairment of luteal function appear important. The serum concentrations of cholesterol and globulin were significantly reduced in women taking norgestrel. Preliminary observations suggest that on discontinuing the medication fertility is promptly restored. Of the 144 women originally enrolled 57 (40%) withdrew for reasons connected with the method before completing 30 months on trial, over half of them because of the irregular menstrual pattern. Nonetheless, in view of its main clinical and laboratory characteristics and simple mode of administration, norgestrel appears to be a useful alternative to the combined type of pill for women unsuitable for, or unable to tolerate, oestrogen-containing preparations.

Full text

PDF
195

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. BROWN J. B. A chemical method for the determination of oestriol, oestrone and oestradiol in human urine. Biochem J. 1955 Jun;60(2):185–193. doi: 10.1042/bj0600185. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Carlborg L. G. Quantitative determination of sialic acids in the mouse vagina. Endocrinology. 1966 Jun;78(6):1093–1099. doi: 10.1210/endo-78-6-1093. [DOI] [PubMed] [Google Scholar]
  3. Carlborg L., Johansson E. D., Gemzell C. Sialic acid content and sperm penetration of cervical mucus in relation to total urinary oestrogen excretion and plasma progesterone levels in ovulatory women. Acta Endocrinol (Copenh) 1969 Dec;62(4):721–731. doi: 10.1530/acta.0.0620721. [DOI] [PubMed] [Google Scholar]
  4. Chiazze L., Jr, Brayer F. T., Macisco J. J., Jr, Parker M. P., Duffy B. J. The length and variability of the human menstrual cycle. JAMA. 1968 Feb 5;203(6):377–380. [PubMed] [Google Scholar]
  5. Foss G. L., Holton J. B., Lewis F. J. Effects of long-term microdosage of norgestrel on glucose tolerance and serum transaminase levels. J Reprod Fertil. 1970 Oct;23(1):185–188. doi: 10.1530/jrf.0.0230185. [DOI] [PubMed] [Google Scholar]
  6. KLOPPER A., MICHIE E. A., BROWN J. B. A method for the determination of urinary pregnanediol. J Endocrinol. 1955 May;12(3):209–219. doi: 10.1677/joe.0.0120209. [DOI] [PubMed] [Google Scholar]
  7. Kremer J. A simple sperm penetration test. Int J Fertil. 1965 Jul-Sep;10(3):209–215. [PubMed] [Google Scholar]
  8. Martinez-Manautou J., Cortez V., Giner J., Aznar R., Casasola J., Rudel H. W. Low doses of progestogen as an approach to fertility control. Fertil Steril. 1966 Jan-Feb;17(1):49–57. doi: 10.1016/s0015-0282(16)35825-3. [DOI] [PubMed] [Google Scholar]
  9. Moghissi K. S., Marks C. Effects of microdose norgestrel on endogenous gonadotropic and steroid hormones, cervical mucus properties, vaginal cytology, and endometrium. Fertil Steril. 1971 Jul;22(7):424–434. doi: 10.1016/s0015-0282(16)38342-x. [DOI] [PubMed] [Google Scholar]
  10. Mukherjee T. K., Wright S. W., Davidson N. J., Fotherby K. Effect of norgestrel on corpus luteum function. J Obstet Gynaecol Br Commonw. 1972 Feb;79(2):175–182. doi: 10.1111/j.1471-0528.1972.tb15776.x. [DOI] [PubMed] [Google Scholar]
  11. RUDEL H. W., MARTINEZ MANAUTOU J., MAQUEO TOPETE M. THE ROLE OF PROGESTOGENS IN THE HORMONAL CONTROL OF FERTILITY. Fertil Steril. 1965 Mar-Apr;16:158–169. doi: 10.1016/s0015-0282(16)35522-4. [DOI] [PubMed] [Google Scholar]
  12. Roland M. Prevention of sperm migration into the uterine cavity by a microdose progestagen. Fertil Steril. 1970 Mar;21(3):211–216. doi: 10.1016/s0015-0282(16)37383-6. [DOI] [PubMed] [Google Scholar]
  13. Smith D. C., Hunter W. B., Spadoni L. R. Alkaline phosphatase concentration in cervical mucus. Fertil Steril. 1970 Jul;21(7):549–554. [PubMed] [Google Scholar]
  14. Spellacy W. N. A review of carbohydrate metabolism and the oral contraceptives. Am J Obstet Gynecol. 1969 Jun 1;104(3):448–460. doi: 10.1016/s0002-9378(16)34204-1. [DOI] [PubMed] [Google Scholar]
  15. WERNER I., ODIN L. On the presence of sialic acid in certain glycoproteins and in gangliosides. Acta Soc Med Ups. 1952;57(3-4):230–241. [PubMed] [Google Scholar]
  16. Wynn J. W., Doar J. W., Mills G. L. Some effects of oral contraceptives on serum-lipid and lipoprotein levels. Lancet. 1966 Oct 1;2(7466):720–723. doi: 10.1016/s0140-6736(66)92979-5. [DOI] [PubMed] [Google Scholar]

Articles from British Medical Journal are provided here courtesy of BMJ Publishing Group

RESOURCES