More U.S. Women Having Twins Because of Infertility Treatments

More U.S. women are having twins because of a rise in infertility treatment and aging mothers, according to the U.S. Centers for Disease Control and Prevention.

One in every 30 babies born today is a twin, an increase from 1 in 53 in 1980, according to the report. The rate doubled among women ages 35 to 39 and tripled among those 40 and over.

Mothers in their late thirties, even without fertility treatments, are likelier to have two babies from the same pregnancy, and there are more older mothers today. Treatments such as in vitro fertilization, and other assisted reproductive technologies, increase the chance of multiple births. More than one baby born at once can lead to lower birth weights and health complications for the babies and the mother, the report said.

By the early 1980s, twins and other multiples “began to rise, ultimately leading to what has been called ‘an epidemic of multiple pregnancies,’” the authors of the report wrote.

To contact the reporter on this story: Elizabeth Lopatto in New York at elopatto@bloomberg.net.

To contact the editor responsible for this story: Reg Gale at rgale5@bloomberg.net.