Increasing uterine receptivity by decreasing estradiol levels during the preimplantation period in high responders with the use of a follicle-stimulating hormone step-down regimen.
OBJECTIVE
To analyze the effect on uterine receptivity of a decrease in E2 levels during the preimplantation period with the use of a step-down regimen in high responders undergoing IVF.


METHODS
Prospective controlled clinical study.


METHODS
The Instituto Valenciano de Infertilidad.


METHODS
High responders in whom at least one previous IVF attempt failed in which 3-4 good-quality embryos were transferred and E2 levels were >3,000 pg/mL on the day of hCG administration.


METHODS
Gonadotropins were administered according to two different protocols. Blood samples were collected and IVF was performed.


METHODS
Serum E2 levels and reproductive outcome of IVF.


RESULTS
Estradiol levels on the day of hCG administration and throughout the preimplantation period and the number of oocytes collected were significantly lower with the use of the step-down regimen than during the previous failed cycle in which the standard protocol was used. The fertilization rate was similar and the number of good-quality embryos transferred was comparable. However, the implantation and pregnancy rates were significantly improved in patients who underwent the step-down regimen compared with those who received the standard protocol.


CONCLUSIONS
With the use of a step-down regimen with FSH in high responders, our clinical results demonstrate that uterine receptivity can be improved when E2 levels are decreased during the preimplantation period.
Instituto Valenciano de Infertilidad and Department of Pediatrics, Obstetrics and Gynecology, Valencia University, Spain. IVI@FUTURNET.ES
C
C
Simón
J J
JJ
Garcia Velasco
D
D
Valbuena
J A
JA
Peinado
C
C
Moreno
J
J
Remohí
A
A
Pellicer
D000328:Adult; D003593:Cytoplasm; D004334:Drug Administration Schedule; D047108:Embryonic Development; D004958:Estradiol / Q000097:blood*; D005260:Female; D005307:Fertilization in Vitro; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008845:Microinjections; D010062:Ovulation Induction / Q000379:methods*; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D013084:Sperm-Ovum Interactions; D014599:Uterus / Q000187:drug effects*
D004958:Estradiol; D005640:Follicle Stimulating Hormone