Author: Heather Montgomery
The birds and the bee’s talk, which we all got when we were younger, made making a baby seem so easy. It went something like this, “When two people love each other, they come together, and make a baby.” In reality, the actual making of a baby can be a complex process. Here is what you need to know about how implantation occurs.
Sperm Meets Egg
When you are ovulating (typically one to two weeks after your last menstrual period), your ovaries release an egg into the opening of the fallopian tubes. After unprotected intercourse, millions of sperm will travel through the cervix and uterus into one of your fallopian tubes. When the sperm meets the egg, one will burrow into the hard outer shell of the egg and fertilize the egg, creating what is called a zygote. Once sperm has made it into the nucleus of the egg, it will undergo a chemical reaction, preventing any of the other millions of sperm from entering.
The Journey Begins
After the egg has been fertilized and has become a zygote, it will begin rapidly dividing into about 100 different cells, and eventually be divided into two sections. The inner section will become the embryo, while the outer section will become the part that nourishes and protects the embryo during development (called the trophoblast). As the zygote comes to the end of your fallopian tube, it will become known as the blastocyst, which has separated the two sections of the zygote. This journey will take 6 to 12 days.
The Uterus Prepares
Once the follicle in your ovary, called the corpus luteum, releases the egg, it will begin to release progesterone. This hormone signals that your uterine lining needs to thicken to prepare for implantation. This process (called “endometrium”) occurs during a period of 12 to 16 days.
Finding a New Home
As soon as the blastocyst exits the fallopian tube, it will burrow into the uterine lining. The trophoblast, which surrounds the embryo, will dissolve the endometrium lining, and later form the placenta. As the trophoblast burrows deeper into the endometrium lining, it envelopes the mothers blood vessels, and they are diverted into the trophoblast structure. The trophoblast will continue to grow larger, as will the embryo within; it will continue burrowing until the entire structure is enveloped by the surrounding endometrium lining. The endometrium lining will become the embryos new home, as the embryo develops.