Embryo implantation is its introduction into the endometrium of the uterus, the success of which determines whether or not pregnancy will develop. Usually it occurs 6-8 days after the fertilization of the egg.
Late embryo implantation
Very rarely, late embryo implantation occurs when a fertilized egg is attached to the uterus more than 10 days after ovulation. Late embryo implantation is usually observed with eco, when a fertilized 2-5-day-old egg is placed in the uterine cavity. If the embryo is attached later than usual, it does not affect its quality in any way. This happens because the implanted egg takes more time to choose the right direction, rather than the one that was originally fertilized inside the woman.
Also, early embryo implantation is rarely observed (within a week after ovulation).
How long does the embryo implantation last?
The time during which the embryo attaches to the endometrium of the uterus is called the implantation window. Usually it lasts from one to three days. After this, the level of hCG starts to rise in the blood, and when performing ultrasound, you can see a fetal egg in 2 mm size.
During implantation, many women experience mild tingling or weak aching pain in the lower abdomen. However, one should not rely on sensation until pregnancy is confirmed by doctors. Also, during the introduction of the embryo, a small amount of blood can be released into the endometrium. Only meager discharges are considered the norm, with heavy bleeding it is necessary to immediately go to the hospital.
Why is an embryo not attached?
The embryo may not attach to the wall of the uterus for the following reasons:
- it carries genetic abnormalities that can not lead to the onset of pregnancy;
- the endometrium is in an unhealthy state.