In vitro fertilization ups the risk of birth defects: study

By Dr. Ananya Mandal, MDJun 14 2010

Dr Ananya Mandal, MD

Researchers have found from a large scale study that in vitro fertilization of IVF is associated with an increased risk of birth defects in the baby. They urge doctors treating patients with infertility to routinely warn them about these risks. The study involved 33 centers for IVF in France and covered over 15,000 births from 2003 to 2007. This study is the largest till date.

Lead researcher Geraldine Viot, from the Maternite Port Royal Hospital in Paris, said: “We found a major congenital malformation in 4.24% of the children, compared with the 2-3% that we had expected from previous published studies...This higher rate was due in part to an excess of heart diseases and malformations of the uro-genital system. This was much more common in boys. Among the minor malformations, we found a five times higher rate of angioma, benign tumors made up of small blood vessels on or near the surface of the skin. These occurred more than twice as frequently in girls than in boys.” She revealed these alarming statistics at a presentation at the annual meeting of the European Society of Human Genetics in Gothenburg, Sweden.

She said that all couples who volunteer for the procedure need to be warned. At present only those who come up with questions are given the details on risks. She said this was a “public health issue” and doctors and politicians should sit up and take notice. She also said that earlier studies have claimed 11% chance of birth defects in babies so born but the actual picture may be different. “Given that our study is the largest to date, we think that our data are more likely to be statistically representative of the true picture,” said Dr Viot.

She is planning to continue looking into the matter by investigating a further 4,000 children born in 2008, and to look at the development of IVF children who are now seven years of age. “By following all these children, we hope to understand more about not only what can go wrong after ART (assisted reproductive technology), but why it goes wrong,” she said. She emphasized that more and more couples are opting for IVF and the actual cause of these defects needs to be pinpointed sooner than later “not only so that we can try to counteract the problem, but also in order for health services to be able to plan for their future needs.”

Some defects are believed to be linked with certain procedures called “imprinting wherein certain genes are switched off or kept active according to which parent they are inherited from. One of these disorders Beckwith Widemann syndrome, was six times more common in the IVF children studied than in the general population. The cause behind this effect is unexplained and many researchers have different views regarding these statistics. Dr. Viot said, “We need more research in order to understand the relationship between embryo culture media, timing of embryo transfer, the effects of ovarian stimulation, the use of ICSI, where sperm is injected directly into the egg, freezing of gametes and embryos and these disorders.”