If you are pregnant with more than one baby, you are far from alone. In the past two decades, the number of multiple births has climbed way up in the United States. In 2005, 133,122 twin babies and 6,208 triplet babies were born in the United States. In 1980 there were only 69,339 twin and 1,337 triplet births.

Why the increase? For one, more women are having babies after age 30. Women in their 30s are more likely than younger women to conceive more than one baby naturally. Another reason is that more women are using fertility treatments to help them conceive. Fertility treatments can increase the likelihood of multiple births.