Twins are amazing to have and quite of bundle of joy and trouble. Twins, today can be found more than usual because of the increased number of fertility treatments. People, today, are busy with their careers and prefer to have children late in their lives. Therefore, fertility treatment is the only way in which they can have children which in most cases results in more than one child. Natural twins are quite rare consisting about 2% of the world. Among the surviving ones also monozygotic twins (which means twins born from one ovum) consist about 8 %. The rest of the twins are dizygotic ones and are quite common.
Monozygotic twins are formed when a single ovum split into two. The reason for such an occurrence is unknown. However, many feel that it hereditary and might even skip a generation or two. While others feel that it can happen because of the mother’s weight, height, race, diet and many more such reasons. Fertility treatments definitely cause women to become pregnant with twins. Monozygotic twins are of the same gender and look alike. Sometime you can find identical siblings not twins existing. Monozygotic twins show similar personalities and have intelligence quotients. However, sometimes mutations occur in which the monozygotic twins differ.
Dizygotic twins, on the other hand, are formed when two separate ovums are fertilised. These get implanted on the wall of the womb. Such twins are known as fraternal ones and are more like siblings. They only share the womb during the gestation time and have their own placentas. Dizygotic twins are common and are not identical. These twins can also be of different sexes.
Twin pregnancy complications
Twin pregnancies can have severe complications at times. Many of the pregnancies that started like a multiple pregnancy often end in a single one.
Vanishing twin: This syndrome can be seen when one of the twin foetuses spotted in the ultrasounds in the first trimester. But ultrasounds conducted later on often do not find both the foetuses. It cannot be clearly said what has happened to one of them. Since the second twin cannot be found later on this is called vanishing twin syndrome.
Miscarried twin: Sometimes if a woman pregnant with twins suffers a miscarriage one of the foetuses is miscarried while the other continues. This is quite similar to the vanishing twin syndrome.
Siamese twins: Also known as conjoined twins these twins can be joined to each other during their birth. If you are wondering what causes conjoined twins the answer is that the single zygote fails to separate completely mostly since the separation start quite late. In fact, conjoined twins have mirror images of each other.
Parasitic twins: Even though the name is quite shocking it is called so for different reason. These twins cause trouble for each other since one of them has a parasitic nature towards the surviving one. Sometimes they cannot be distinguished from the one another.
Twins are an interesting subject of study for scientists dealing in human nature and development.