What are maternal twins?

Maternal twins refers to a specific scenario in which twins develop from a single female reproductive event, involving one egg (ovum) from the mother with involvement from just one sperm. Unlike fraternal twins, who develop from two distinct eggs fertilized by separate sperm, maternal twins are identical in genetic makeup.

Here's a breakdown of what maternal twins are and how they form:

1. Origin: Maternal twins originate from the same fertilized egg (zygote) that has undergone division. This process is known as monozygotic twinning or identical twinning.

2. Single Egg: In the case of maternal twins, the mother releases a single egg from one of her ovaries, which is then fertilized by a single sperm. Fertilization occurs as usual, resulting in the formation of a zygote.

3. Division of the Zygote: The zygote then undergoes early embryonic division. During this process, the zygote splits into two separate embryos, each with its own set of genetic material. These two embryos develop into separate individuals, sharing identical DNA.

4. Identical Genetic Makeup: Since maternal twins originate from the same fertilized egg, they have the same genetic makeup. They are considered genetically identical, sharing the same physical traits, blood type, and other genetic characteristics.

5. Placentation: Depending on the specific scenario, maternal twins can share the same placenta or have separate ones. They can be either monochorionic (sharing the same placenta) or dichorionic (having separate placentas).

It's important to note that while maternal twins share the same genetic makeup, they can still exhibit individual differences due to environmental factors and unique experiences throughout their development and life.