In Vitro Linked to Rare Bladder Defects
Disorder Among Conditions Linked to Babies Born Through In Vitro Fertilization
But his finding, published in the April issue of the Journal of Urology, is the latest discouraging news associating in vitro fertilization to a host of medical problems. In January, Dutch researchers reported in The Lancet that in vitro fertilization babies are up to seven times more likely to have a rare cancer of the retina that affects about one in 17,000 births. And last March, two studies in The New England Journal of Medicine suggested that low birth weight and defects such as Down syndrome were twice as high for babies born to mothers who undergo either in vitro fertilization or intracytoplasmic sperm injection (ICSI). And just one month earlier, another Lancet study linked in vitro fertilization with higher rates of various brain disorders, including cerebral palsy.
In vitro fertilization, retrieved eggs and sperm from the parents are placed together in a laboratory dish to enhance the likelihood of fertilization. If it occurs, the eggs are transferred back into the woman's uterus, where implantation and embryo development would hopefully occur as in a normal pregnancy.
There are various theories on why in vitro fertilization-conceived children seem to have a higher risk of medical problems -- from problems with the preserving solution in the dish that houses the sperm and egg to mistakes in the procedure itself. "Our theory is that bladder exstrosphy and other defects could result from mishandling of the fertilized egg during implantation or some kind of metabolic problem induced by the procedure of implantation itself," Gearhart tells WebMD.
But Robert Brzyski, MD, PhD, president of the professional association representing in vitro specialists at 370 clinics across the U.S., has his own theory. "We cannot discount the lab environment or other factors, but something in the couple's inability to naturally have a child may predispose them to adverse outcomes in general," says Brzyski, of the Society for Assisted Reproductive Technologies and an ob-gyn at the University of Texas Health Science Center at San Antonio.
Like other assisted reproductive techniques, in vitro fertilization is usually reserved for couples who cannot conceive a child naturally for at least a year.