Gene expression during successful implantation in a natural cycle.

OBJECTIVE

To determine the human endometrial transcriptome during embryonic implantation.

DESIGN

Case report.

SETTING

Tertiary fertility center.

PATIENT(S): A 24-year-old woman who inadvertently became pregnant during an endometrial biopsy procedure.

INTERVENTION(S): An endometrial biopsy was performed with a Pipelle device during the midluteal phase (days 19-21) of the cycle; blood samples for hormonal assessments were collected and a transvaginal ultrasound was performed.

MAIN OUTCOME MEASURE(S): Gene expression analysis of the endometrium during the window of implantation (during the implantation of an embryo) in a natural cycle. Localization of selected genes in endometrial tissue with immunohistochemistry.

RESULT(S): A total of 394 probe sets were differentially expressed in the pregnant sample when compared with the midsecretory phase nonpregnant endometrial samples. Different gene networks were involved, and selected genes from these signaling pathways were confirmed at the protein level.

CONCLUSION(S): Endometrial gene expression of a pregnant patient in a natural cycle is significantly different from nonpregnant patients during the midsecretory phase.