Do Twins Run in Families? What to Know About the Heredity of

Yes, twins do run in families. The tendency to have twins is inherited from both the mother and the father. However, the exact genetics of twinning are not fully understood.

What is the chance of having twins?

The chance of having twins varies from woman to woman. Some women are more likely to have twins than others. Factors that can increase the chance of having twins include:

* Family history of twins. If you have a close family member (such as a parent or sibling) who is a twin, you are more likely to have twins yourself.

* Age. Women who are over 35 are more likely to have twins.

* Race. African American women are more likely to have twins than women of other races.

* Weight. Women who are overweight or obese are more likely to have twins.

* Fertility treatments. Women who use fertility treatments, such as in vitro fertilization (IVF), are more likely to have twins.

What are the different types of twins?

There are two main types of twins:

* Identical twins. Identical twins are formed when a single fertilized egg splits into two embryos. Identical twins are always the same sex and have the same genetic makeup.

* Fraternal twins. Fraternal twins are formed when two separate eggs are fertilized by two different sperm. Fraternal twins can be either the same sex or different sexes. They do not have the same genetic makeup as identical twins.

Are twins healthy?

Most twins are healthy. However, twins are more likely to have certain health problems, such as:

* Premature birth. Twins are more likely to be born prematurely than single babies.

* Low birth weight. Twins are more likely to have a low birth weight than single babies.

* Birth defects. Twins are more likely to have birth defects than single babies.

* Twin-to-twin transfusion syndrome (TTTS). TTTS is a condition that can occur in identical twins who share a placenta. TTTS can lead to serious health problems, such as heart failure and brain damage.

What is the outlook for twins?

The outlook for twins is generally good. Most twins grow up to be healthy and productive adults. However, twins may need special care during pregnancy and infancy.

If you are pregnant with twins, talk to your doctor about the risks and complications of twin pregnancy. Your doctor can help you ensure that you and your twins have a healthy pregnancy and delivery.