More About How Twins Are Formed
Quite different from a single baby, this fertilized egg cell will later get split into two separate embryos. That’s a sign that the couple is having identical twins. This change takes place within the first fertilization week and can quickly happen multiple times. This split can take place at the two-cell stage within days 1 to 3. It can even take place at the early blastocyst stage, from days 4 to 6. Sometimes, the fertilized egg gets split into two in the late blastocyst stage, occurring within days 7 to 9.
When the egg cell splits into two, that’s the time to determine how these twins will be implanted in the uterine lining. These eggs might share chorion, amnion, and placenta, but that isn’t always the case. They may not share it at some point. If the splitting takes place earlier, the twins will become more independent and will develop with ease inside the uterus. So, if the pair splits during the initial two-cell stage, then each one will have its own chorion, amnion, and placenta. Otherwise, if the fertilized egg splits later during the last blastocyst stage, there are higher chances of twins sharing chorion, placenta, and amnion.
There tends to be a general misconception when it comes to twins. People believe that if there are twins in the mother’s gene, the chances are high that there will be a twin in the family later. But the truth is complicated. Science failed to pinpoint the real reason behind the formation of identical twins, even to this date. For some, it is just a miracle!