CDC: 1 in 100 babies conceived in vitro

ATLANTA, June 20 (UPI) -- One of every 100 U.S. babies was a test-tube baby and about half of them were twins, triplets or higher, a U.S. health agency reported.

The Centers for Disease Control in Atlanta's most recent data on in vitro fertilization covers the year 2005, WebMD.com reported Friday. The information came from 422 of the 475 U.S. medical centers assisting people with fertility problems to conceive.

The report points up a major IVF issue: multiple births. While IVF led to 1 percent of births in 2005, it was responsible for 16 percent of twins and 38 percent of triplets or higher multiples.

IVF is expensive and had a 35 percent chance of resulting in a live birth in 2005, WebMD.com said. Because of the success rate then, doctors often implant multiple embryos into a woman's womb.

About 42 percent of IVF infants born in 2005 were preterm, compared with approximately 13 percent of preterm births in the general U.S. population, the CDC's Victoria Clay Wright and colleagues said in their report.

Fertility specialists now encourage single-embryo procedures. Wright said efforts to limit the number of embryos transferred in each procedure "should be continued and strengthened."