Doctors do not fully understand the reason why twin pregnancies sometimes occur and also, some factors can increase the likelihood of giving birth to twins, including:
- The woman’s age
- Having a family history of twins
- Having fertility treatments
Conception happens when the sperm fertilizes an egg to form an embryo. However, if there are two eggs present in the womb at the time of fertilization or the fertilized egg splits into two separate embryos, a woman can become pregnant with twins.
There are two types of twin:
Identical twins: This type of pregnancy happens when a fertilized egg splits into two separated embryos. These embryos are mono-zygotic, which means that they have identical genes. Identical twins have the same sex as each other and look very alike.
Non identical, or fraternal, twins: This type of pregnancy occurs when there are two eggs present in the womb at the time of fertilization, and sperm fertilize both of them. These embryos are dizygotic, which means that they do not have identical genes and may not be the same sex.
Fraternal twins are common after fertility treatment because the healthcare professionals often place two fertilized embryos into a woman’s womb to increase the chances of a successful pregnancy.
Risks linked with twin births:
Premature birth: Twins who are born prematurely more than half the time which is a before the end of 36 weeks of the pregnancy and also Premature babies may have health problems as a new-borns Sometimes they also have lasting disabilities.
Low birth weight (LBW): is more than half of twins are born with LBW, weighing less than 5 1/2 pounds. LBW babies are at increased risk of the health problems after birth, such as
- Vision and hearing loss
- Mental disabilities
- Cerebral palsy
This is more likely if babies are born before 32 weeks they are weighing less than 3 1/3 pounds.