Implantation is a process in which a developing embryo, moving as a blastocyst through a uterus, to make contact with the uterine wall and remains attached to it until birth. The lining of the uterus which is called endometrium prepare for the developing blastocyst too attached to it via many internal changes. Implantation is the stage of pregnancy at which the embryo adheres to the wall of the uterus. At this stage of prenatal development, the conceptus is called the blastocyst. It is by this edition that the embryo receives oxygen and nutrients from the mother to be able to grow. Under normal circumstances comma fertilization occurs in one of the fallopian tube, then the fertilized egg begins to make its way to the uterus. On the 5th day after fertilization, the embryo finally reaches to the uterus, where it implants itself in the endometrium or uterine lining.
Embryo implantation failure is one of the reasons of infertility. Many embryos are not able to implant after transfer to the uterus because they are not healthy enough to grow. Even embryos that look good in the lab may have defects that cause them to die instead of growing. Stress also plays a major role in embryo implantation. When patient is going under IVF and IUI procedures stress can effect hormone that reduce blood flow to the uterus and endometrium lining making it less receptive to implantation.
Human blastocyst should hatch from the shell and begin to implant 1-2 days after day 5 blastocyst transfer. In a natural situation, the blastocyst should hatch and implant at the same time about 6 to 10 days after ovulation. The sign and symptom of implantation are your body’s way of welcoming you to pregnancy. While many women don't feel anything during the process, others report swollen breasts, light bleeding and a tender abdomen. Some feel woozy or have headache.