Biomaterial Database

The effects of peri-ovulatory administration of levonorgestrel on the menstrual cycle. 2001

D Hapangama, and A F Glasier, and D T Baird

Contraceptive Development Network, Department of Reproductive and Development Sciences, The University of Edinburgh, Centre of Reproductive Biology, EH3 9ET, Edinburgh, Scotland, United Kingdom.

Levonorgestrel (LNG) 0.75 mg administered 12 h apart within 72 h of unprotected coitus, is an established method of emergency contraception (EC). The mechanism of action of LNG used in this manner is unknown. We administered LNG 0.75 mg twice immediately before ovulation, to test the hypothesis that LNG acts as an emergency contraceptive by abolishing the pre-ovulatory lutenizing hormone (LH) surge and thereby delaying ovulation. Twelve women took LNG on or before the day of the first significant rise in urinary LH in 12 cycles. In four women, the LH peak and the onset of next menses were significantly delayed (delay of 16.8 days (SD +/- 8.7) from the day of mean LH peak in placebo cycles). One woman did not ovulate at all, despite a normal LH peak and cycle length. In the remaining eight women, LNG did not affect ovulation or the cycle length, but the length of the luteal phase and the total luteal phase LH concentrations were significantly reduced. We suggest that LNG acts as an emergency contraceptive by other mechanisms as well as delaying the LH surge and interfering with ovulation.

UI	MeSH Term	Description	Entries
D007986	Luteinizing Hormone	A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Luteinizing hormone regulates steroid production by the interstitial cells of the TESTIS and the OVARY. The preovulatory LUTEINIZING HORMONE surge in females induces OVULATION, and subsequent LUTEINIZATION of the follicle. LUTEINIZING HORMONE consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH and FSH), but the beta subunit is unique and confers its biological specificity.	ICSH (Interstitial Cell Stimulating Hormone),Interstitial Cell-Stimulating Hormone,LH (Luteinizing Hormone),Lutropin,Luteoziman,Luteozyman,Hormone, Interstitial Cell-Stimulating,Hormone, Luteinizing,Interstitial Cell Stimulating Hormone
D008183	Luteal Phase	The period in the MENSTRUAL CYCLE that follows OVULATION, characterized by the development of CORPUS LUTEUM, increase in PROGESTERONE production by the OVARY and secretion by the glandular epithelium of the ENDOMETRIUM. The luteal phase begins with ovulation and ends with the onset of MENSTRUATION.	Menstrual Cycle, Luteal Phase,Menstrual Cycle, Secretory Phase,Menstrual Secretory Phase,Postovulatory Phase,Phase, Luteal,Phase, Postovulatory,Secretory Phase, Menstrual
D008597	Menstrual Cycle	The period from onset of one menstrual bleeding (MENSTRUATION) to the next in an ovulating woman or female primate. The menstrual cycle is regulated by endocrine interactions of the HYPOTHALAMUS; the PITUITARY GLAND; the ovaries; and the genital tract. The menstrual cycle is divided by OVULATION into two phases. Based on the endocrine status of the OVARY, there is a FOLLICULAR PHASE and a LUTEAL PHASE. Based on the response in the ENDOMETRIUM, the menstrual cycle is divided into a proliferative and a secretory phase.	Endometrial Cycle,Ovarian Cycle,Cycle, Endometrial,Cycle, Menstrual,Cycle, Ovarian,Cycles, Endometrial,Cycles, Menstrual,Cycles, Ovarian,Endometrial Cycles,Menstrual Cycles,Ovarian Cycles
D010060	Ovulation	The discharge of an OVUM from a rupturing follicle in the OVARY.	Ovulations
D011276	Pregnanediol	An inactive metabolite of PROGESTERONE by reduction at C5, C3, and C20 position. Pregnanediol has two hydroxyl groups, at 3-alpha and 20-alpha. It is detectable in URINE after OVULATION and is found in great quantities in the pregnancy urine.
D011446	Prospective Studies	Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.	Prospective Study,Studies, Prospective,Study, Prospective
D003281	Contraceptives, Postcoital	Contraceptive substances to be used after COITUS. These agents include high doses of estrogenic drugs; progesterone-receptor blockers; ANTIMETABOLITES; ALKALOIDS, and PROSTAGLANDINS.	Emergency Contraceptive,Morning-After Pill,Postcoital Contraceptive,Postcoital Contraceptives,Contraceptive Agents, Post-Coital,Contraceptive Agents, Postcoital,Contraceptives, Post-Coital,Emergency Contraceptives,Contraceptive Agents, Post Coital,Contraceptive, Emergency,Contraceptive, Postcoital,Contraceptives, Emergency,Contraceptives, Post Coital,Morning After Pill,Post-Coital Contraceptive Agents,Post-Coital Contraceptives,Postcoital Contraceptive Agents
D004311	Double-Blind Method	A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.	Double-Masked Study,Double-Blind Study,Double-Masked Method,Double Blind Method,Double Blind Study,Double Masked Method,Double Masked Study,Double-Blind Methods,Double-Blind Studies,Double-Masked Methods,Double-Masked Studies,Method, Double-Blind,Method, Double-Masked,Methods, Double-Blind,Methods, Double-Masked,Studies, Double-Blind,Studies, Double-Masked,Study, Double-Blind,Study, Double-Masked
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man