What is an implantation bleed?
Pregnancy begins with the fertilization of an egg, which is still in the fallopian tube after ovulation. After fertilization, it migrates towards the uterus, divides and develops along the way and nests in the lining of the uterus. This process can lead to bleeding, which is called implantation bleeding. Medically it is called nidation bleeding. It is a very normal event that can occur in some women and does not harm the mother or the child.
When does implantation bleeding occur?
The female cycle begins with the first day of menstruation. About 14 days after the beginning of the last period, ovulation occurs. A mature egg jumps from the ovary into the fallopian tube and can be fertilized within the next 12 to 24 hours.
If fertilization occurs during this period, the sperm and egg fuse together. The fertilized egg develops and divides further and is transported to the uterus by small cilia over the next five days. There it approaches the lining of the uterus.
Approximately six days after fertilization, i.e. six to seven days after ovulation, it attaches itself to the lining of the uterus and becomes embedded in it. This process is called implantation or nidation. When it nests in the lining of the uterus, a small amount of bleeding can occur, which is called nidation bleeding.
This occurs approximately five to ten days after sexual intercourse that led to fertilization. This period generally corresponds to the 20th to 25th day of the cycle. However, it happens that the small amount of blood initially collects in the uterus and later drains away.
Thus, the day of implantation bleeding shifts backwards. For this reason, implantation bleeding can easily be confused with menstruation. Overall, implantation bleeding occurs in only a quarter of women.
What does an implantation bleeding feel like?
Some women feel the implantation of the fertilized egg, others do not. Both cases are quite normal and neither of them can be considered better or healthier. If pain occurs during implantation, it often feels like a slight pulling or pricking in the lower abdomen.
In addition, abdominal pain with cramps can occur. Sometimes the implantation pain radiates additionally into the back. Often the pain during implantation is very similar to the pain the woman feels during her menstruation. In contrast, however, they usually last much shorter and are not as severe as the pain during menstruation. If the pain lasts for a longer period of time and is strong, a doctor should be consulted and advice should be sought.
