How long does it take for the egg to implant after fertilization?

I believe that everyone who has experienced it knows that having a baby is not an easy thing. During the entire pregnancy preparation process, you need to pay attention to the right time, place and people. After the egg is fertilized, the sperm enters the uterus and combines with the egg in the fallopian tube. The fertilized egg undergoes rapid cell division and moves slowly toward the uterine cavity with the swaying of the cilia on the fallopian tube wall until it finally implants. The whole process takes about 5 to 6 days and can be extended to ten days.

After sexual intercourse, the semen ejaculated by the male contains more than 100 million to 300 million sperms. This huge "team" is "rushing" upstream in the female reproductive tract. The sperm swims at a speed of 2-3 mm per minute by swinging its tail. After a long "journey" - the vagina, cervix, and uterine cavity, it reaches the fallopian tube, where the sperm and egg (actually the secondary oocyte that remains in the metaphase of the second meiotic division) "meet". The head and body of the sperm enter the egg cell, and the sperm cell membrane fuses with the egg cell membrane. This egg is called a fertilized egg. Often only one sperm can enter the egg cell and combine with it to form a fertilized egg. This biological reaction that prevents multiple sperm from entering the egg cell is called the zona pellucida reaction.

Attachment With the partial perforation or total disappearance of the zona pellucida, the trophoblast near one end of the inner cell mass rapidly divides, and the tiny villi on the two opposite tissue surfaces, close to the endometrial epithelium, span the gap, widely intertwine in a finger-like manner, and then the villi are intertwined with each other.

After the implanted blastocyst (also known as embryocyst) attaches to the endometrium, the cell membrane of the endometrial epithelial cells gradually disappears and becomes a multinucleated cell body. The trophoblast also differentiates into two layers. The inner layer retains the cell membrane, which is called the cytotrophoblast. The outer cell membrane disappears, called the syncytiotrophoblast. The syncytiotrophoblast has a strong corrosive power, eroding the uterine deciduous membrane, forming a small gap, allowing the blastocyst to slowly sink under the dense layer of the endometrium. About 10 days after fertilization, the entire blastocyst is located in the endometrium. On the 11th day, there is a closure plug composed of small blood clots and cell fragments in the endometrium. On the 12th day, the blastocyst is almost completely covered by the proliferating epithelium and forms a small bulge, and implantation is complete.