Many couples seeking infertility treatments desire multiple births--twins, triplets, or more babies in one pregnancy--but have poor knowledge about the risks.

That's the conclusion of a University of Iowa study that appeared in the journal Fertility and Sterility. The risks include higher rates of infant death and long-term disabilities such as cerebral palsy. The added risk for twins was particularly poorly understood.

"Most of the twins seen in public or on the news are success stories," said Ginny Ryan, M.D., the study's co-author. "However, there are many risky and unsuccessful twin pregnancies."

The investigation found that one in five women seeking treatment preferred multiples over a single baby. While patients usually knew about risks of triplets and higher order multiples, less than half knew about twins' increased risk of cerebral palsy. Only 30 percent knew of the increased risk of infant death, which is eight times higher for twins than for singletons.

"From a health care standpoint, we think it's important to educate couples about risks so they can truly make good decisions," said Brad Van Voorhis, M.D.