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Updated: Aug 25, 2026
Establishment of an Embryo Implantation Model In Vitro
Published on: June 21, 2024
Premature progesterone elevation spares blastulation but not pregnancy rates in in vitro fertilization with coculture
R Fanchin1, A Hourvitz, F Olivennes
1Hôpital Antoine Béclère, Clamart, France.
Objective:
To clarify whether embryo development to the blastocyst stage may be affected by premature P elevation during controlled ovarian hyperstimulation (COH) for IVF-ET with embryo coculture.
Design:
Retrospective study.
Setting:
Tertiary care infertility center.
Patient(S):
One hundred thirty-one women undergoing 153 IVF-ET cycles with embryo coculture.
Intervention(S):
Patients underwent COH with GnRH agonist and hMG. Embryos were cocultured up to the blastocyst stage. According to plasma P levels on the day of hCG, two groups were defined: low P (P < or = 0.9 ng/mL; conversion factor to SI unit, 3.180) and high P (P > 0.9 ng/mL).
Main Outcome Measure(S):
Blastulation (number of blastocysts/number of noncavitating embryos x 100) and pregnancy rates (PRs).
Result(S):
Blastulation rates were similar in the low and high P groups (51% and 48%, respectively). Moreover, patients included in the high P groups achieved significantly lower clinical and ongoing PRs (12% versus 29% and 7% versus 25%, respectively).
Conclusion(S):
The lack of difference in blastulation rates between the groups further supports the hypothesis that premature P elevation does not alter oocyte and embryo quality. Hence, the observed decrease in PRs is likely to reflect impaired endometrial receptivity in the high P group.
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