Endometrial gene expression in the window of implantation is altered in obese women especially in association with polycystic ovary syndrome.

OBJECTIVE: To determine whether luteal phase endometrial transcriptome is altered in obese women during the window of implantation (WOI), considering the presence of infertility, fat distribution and association with polycystic ovary syndrome (PCOS).
DESIGN: Prospective study.
SETTING: University-affiliated infertility clinic, between May 2007 and March 2009. PATIENT(S): One control group of women with normal weight (n=4), and four study groups of obese women (n=6 each one) according to the association with infertility, PCOS, and ovarian stimulation. INTERVENTION(S): The endometrium was biopsied 7 days after LH surge or hCG administration in 28 women. MAIN OUTCOME MEASURE(S): Endometrial gene expression during the WOI. RESULT(S): One hundred and fifty-one genes were dysregulated in obese groups compared with controls. This dysregulation was more pronounced when infertility was associated. The biologic processes of these genes belonged mainly to development and regulation of different biological functions such as transcription and biosynthesis. The molecular functions overrepresented were transcription and peptide receptor activity. The endometrium of obese women with PCOS showed dysregulated genes related to biologic processes such as development, morphogenesis, and the immune system, as well as different molecular functions such as protein binding, binding, growth factor activity, and carboxylic acid transmembrane transporter activity. Some of these genes have been previously related to implantation and unexplained infertility. CONCLUSION(S): Obese women present a different endometrial gene expression than controls during the WOI, which is more pronounced when infertility or polycystic ovary syndrome are associated.