A single midcycle dose of levonorgestrel similar to emergency contraceptive does not alter the expression of the L-selectin ligand or molecular markers of endometrial receptivity.
OBJECTIVE
To examine the effects of a single-dose of 1.5 mg of levonorgestrel (commonly used as emergency contraceptive) on endometrial receptivity biomarkers through the oral or vaginal route.


METHODS
Prospective randomized single-blinded trial.


METHODS
Affiliated Hospital and University Research Center.


METHODS
Fertile normal women previously sterilized by tubal ligation.


METHODS
Levonorgestrel (1.5 mg) was administered on the day of LH surge either orally (n = 14) or vaginally (n = 13).


METHODS
Molecular assessment of endometrial progesterone receptors, L-selectin ligand, glicodelin-A and αvβ3 integrin by Immunohistochemistry and reverse transcriptase-polymerase chain reaction.


RESULTS
Plasma progesterone concentration and endometrial dating were not different. The pattern of progesterone receptors and glycodelin-A expression was not affected during the early and midsecretory phase. Some endometrial biopsies from the group in which levonorgetrel was orally administered showed areas of glandular atrophy and stromal decidualization. However, the expression of the progesterone receptor, L-selectin ligand, αvβ3 integrin, and glycodelin-A were not different between the groups.


CONCLUSIONS
Levonorgestrel, given as emergency contraceptive on the day of LH surge, does not disrupt either ovulation or progesterone production by the corpus luteum. The contraceptive mechanism of levonorgestrel at the time of LH surge does not include changes in the progesterone receptors or the endometrial receptivity biomarkers.
Palomino
Wilder Alberto
WA
Instituto de Investigaciones Materno Infantil, Universidad de Chile, Santiago de Chile, Chile. apalomino@med.uchile.cl
Kohen
Paulina
P
Devoto
Luigi
L
D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D044363:Contraception, Postcoital; D003271:Contraceptive Agents, Female / Q000494:pharmacology; D004717:Endometrium / Q000187:drug effects* / Q000378:metabolism* / Q000473:pathology; D005260:Female; D000071816:Glycodelin; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D039302:Integrin alphaVbeta3 / Q000378:metabolism; D019041:L-Selectin / Q000378:metabolism*; D016912:Levonorgestrel / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000378:metabolism; D008597:Menstrual Cycle / Q000502:physiology*; D011257:Pregnancy Proteins / Q000378:metabolism; D011374:Progesterone / Q000097:blood; D011446:Prospective Studies; D011980:Receptors, Progesterone / Q000378:metabolism; D016037:Single-Blind Method
D015415:Biomarkers; D003271:Contraceptive Agents, Female; D000071816:Glycodelin; D006023:Glycoproteins; D039302:Integrin alphaVbeta3; C045246:PAEP protein, human; D011257:Pregnancy Proteins; D011980:Receptors, Progesterone; D019041:L-Selectin; D011374:Progesterone; D016912:Levonorgestrel; D007986:Luteinizing Hormone