Twins, Triplets or More

A "twins or more" pregnancy may be referred to as a multiple pregnancy or multiple gestation. This means simply that a mother is carrying more than one baby. The incidence of multiple gestation is increasing in the United States. Following are questions that are often asked about multiple gestation.

How often do multiple births occur?

In 2003, there were 128,665 babies born as twins in the U.S..  One out of   every 31 babies born was a twin. There were 7,110 born as triplets, 468 as quadruplets, and 85 were born as quintuplets or more.

Why do multiple births occur?

There are two types of multiple pregnancies. Identical twins develop when a single fertilized egg divides. The babies will be the same sex and will probably look alike. One out of every 250 babies born is an identical twin. This rate has stayed the same through history and is not affected by the mother’s age, race or family history.

Fraternal twins develop when two eggs are fertilized. These twins may or may not be the same sex. They may or may not look alike. Women over the age of 30 and women with a family history of fraternal twins are more likely to have fraternal twins.

Did you know that more multiples are being born?

More multiples are being born.  The two major causes are 1)women waiting until later in life to have babies and 2)fertility treatment. A woman’s chance of having a multiple birth increases with age, and peaks at 45 years. Twice as many triplet, quadruplets, quintuplets, and quintuplets-plus are being born now as in 1991. When fertility drugs are not used, the odds of having triplets are close to 1 in 8,000; quadruplets 1 in 700,000; and quintuplets 1 in 65,610,000 births. The likelihood of having multiples increases dramatically with fertility drugs.

For additional information about multiple pregnancy and birth:

http://www.nomotc.org/facts.htm  

http://www.tripletconnection.org/