Question

How does the uterus prepare itself for the implantation of the embryo, & what happens when the implantation doesn't take place?

Answer 1

After 8-9 days, fertilized ovum adheres to the wall of uterus through a process called as implantation. At uterus developing embryo gets nutrients from mother and grows. For implantation purpose uterus undergoes several morphological changes like inner lining of uterus that is endometrium becomes thick. Actually blood vessels and glands in the endometrium increase in size and number so that this layer becomes thick. Vesicular spaces in the endometrium fuses and become interconnected, giving rise to structure called as placenta, which supplies nutrients from mother to the developing embryo in uterus.

When embryos fail to implant and give rise to a pregnancy, they die and disintegrate. Cells die in the human body all the time, and these dead cells are removed by body’s scavenging machinery. When mother get periods after a failed cycle, only the endometrium which is formed during that particular IVF cycle is sloughed off. Since it took lots of hormones , your endometrial lining might be thicker than usual and you might experience heavier menstrual bleeding or you might have more clots (which appears like a tissue) than you normally do. This doesn’t mean you are having a miscarriage or that the transferred embryo was expelled.