The likelihood of birth defects in multiples has risen over the past 24 years in Europe—and the cause could be in vitro fertilization.
Researchers at the University of Ulster in Northern Ireland found that, in 14 European countries, the rate of birth defects in multiples nearly doubled from 6 in 10,000 births in 1984 to 11 in 10,000 births in 2007.
The study concluded that multiple babies have a near one-third higher risk of birth defects than single babies. The birth defects that occurred more often were non-chromosomal ones like physical deformities.
Helen Dolk, the senior author of the study, said that the rise in defects could be due to multiple embryo transfers in IVF: "Most babies are born healthy from multiple births or (IVF), but there are a number of reasons why single embryo transfers is a better option than multiple embryo transfer," she said.