How long does it take for the embryo to implant in the uterus?

Embryo implantation is the stage in pregnancy in which the fertilized egg, also called a blastocyst, attaches itself to the uterine wall lining. This implantation marks the commencement of pregnancy. In other words, until the implantation takes place, a woman is not regarded as pregnant.

When Does Implantation Take Place in Normal Pregnancies?

To get an answer to this question, you will have to understand how you become pregnant. Here is a step by step guide:

• When you engage in unprotected sex, sperm passes through the vagina and get past the cervix to reach up to the fallopian tubes. Here, a sperm is most likely to combine with an egg.
• When the sperm combines with the egg, fertilization takes place.
• The fertilized egg then travels up to the uterus for implantation. At the same time, it continues to grow in size even as its cells divide and reproduce.
• Once this fertilized egg finds the right spot in the uterine wall to attach itself, it gets ready to implant at that spot.
• With implantation, the fertilized egg gets attached to the uterus lining and the pregnancy starts. About 30% of women experience slight bleeding when implantation occurs in their uterus.

So, the embryo implantation time in the uterus is generally 7 to 14 days after you have had sex.

When Does Implantation Take Place in IVF?

In the case of in vitro fertilization (IVF), the fertilized eggs or human blastocysts normally hatch out of their shell and start to implant about 1 or 2 days after the 5th day of the IVF blastocyst transfer. This means the implantation takes place about 7 to 8 days after fertilization of the egg. The time required for implantation in both the cases, normal pregnancy and pregnancy through IVF, is more or less the same.