How wide is the uterine implantation window?

Uterine ALK3 is essential during the window of implantation.

The window of implantation is defined by the inhibition of uterine epithelial proliferation, structural epithelial cell remodeling, and attenuated estrogen (E2) response. These changes occur via paracrine signaling between the uterine epithelium and stroma. Because implantation defects are a major cause of infertility in women, identifying these signaling pathways will improve infertility inter...

Ultrastructural Modifications of Human Endometrium during the Window of Implantation

The endometrium is a highly dynamic tissue empowered with the capacity to undergo cyclic dramatic changes in response to ovarian steroid hormones, ultimately aiming to create a window of receptivity for blastocyst implantation. Intensive research has been performed to understand and establish morphological and molecular correlates of embryo implantation. However, it still remains a biological m...

ART and uterine pathology: how relevant is the maternal side for implantation?

BACKGROUND Assisted reproduction technology (ART) has become a standard treatment for infertile couples. Increased success rates obtained over the years have resulted primarily from improved embryo quality, but implantation rates still remain lower than expected. The uterus, an important player in implantation, has been frequently neglected. While a number of uterine pathologies have been assoc...

Decreasing Entropy: How Wide to Open the Window?

Estrogen is a critical determinant that specifies the duration of the window of uterine receptivity for implantation.

Many underlying causes of human infertility have been overcome by using in vitro fertilization (IVF) and embryo transfer (ET) techniques. Nevertheless, implantation rates in IVF programs remain low despite the transfer of apparently healthy embryos. This suggests that there are problems with the differentiation of the uterus to the receptive state in response to the ovarian hormones estrogen an...