|Kim Porter & P. Diddy with twins D’Lila and Jessie in 2008|
More U.S. women are having twins these days. The reason? Older moms and fertility treatments.
One in every 30 babies born in the U.S. is a twin — an astounding increase over the last three decades, according to a government report issued Wednesday. In 1980, only 1 in every 53 babies was a twin.
“When people say it seems like you see more twins nowadays, they’re right,” said Joyce Martin, an epidemiologist who co-authored the Centers for Disease Control and Prevention report.
Some increase was expected as more women are waiting until they are over 30 to have babies. For some unknown reason, mothers in their 30s are more likely to have twins than younger or older women. As much as a third of the increase can be attributed to that, Martin said.
The rest of the rise is due to fertility drugs and treatments, experts said.
“You have a double whammy going on. There are more older moms and more widespread use of fertility-enhancing therapies,” Martin said.
Starting in the early 1980s, couples who had trouble conceiving began to benefit from medical advances like fertility drugs and in vitro fertilization and other procedures. These treatments became fairly widespread in the 1990s but are expensive, and availability and insurance coverage varies.
The twin birth rate rose by more than 2 percent a year, on average, from 1980 through 2004. It leveled off to less than 1 percent annually although the rise from 2008 to 2009 was nearly 2 percent.
In 2009, twin rates increased in all 50 states, though the jumps were highest in lower New England, New Jersey and Hawaii. In Connecticut, twins now account for nearly 5 percent of births.
That’s high. Nationally, 3.3 percent of all births were twins in 2009, up from 2 percent in 1980.
Over the last three decades, rates rose for white, black and Hispanic women, but the increases were not uniform. Rates doubled for whites, rose by half for blacks and by about a third for Hispanics. Historically, black moms have twins most often, but white moms have almost caught up.