Double Take: Where’d All These Twins Come From?

If you’ve been noticing more twins around lately, it’s not just double vision. New data from the Centers for Disease Control and Prevention confirm that more twins are being born today than ever before. In fact, one in every 30 babies born in the US in 2009 was a twin.

Contrary to what some have said, oral contraceptive use is not a factor in the twin boom. The two main reasons for the increase: age of mother and fertility drugs. Women in their 30s—particularly those from 35 to 39—are more likely to ovulate more than one egg at a time, leading to historically higher rates of naturally conceived twins. With more than one-third of all US births occurring among women age 30 and older, the math adds up to more twins. Additionally, more couples of all ages are pursuing assisted reproductive technologies such as fertility drugs or in vitro fertilization, which increase the odds of a twin pregnancy.

While having twins can be twice as nice, there are some very real health concerns that come with carrying two or more embryos. Preterm labor is more common among twin pregnancies and frequently results in preterm birth. Roughly half of twins are delivered early, sometimes before they have fully developed. When compared to singleton babies, twins are more likely to be born small and require more hospitalization. Women carrying twins also have a higher likelihood of developing high blood pressure, preeclampsia, anemia, and other conditions. Efforts are ongoing to improve infertility treatments to avoid multiple gestation pregnancies.

With proper prenatal care and monitoring, it is possible to deliver a healthy pair of babies. However, women should be aware of the risks of carrying twins and work closely with their doctors to ensure a healthy pregnancy and delivery of two bundles of joy.