IVF children and congenital defects

More than 30 years ago, the first in vitro fertilized (IVF) baby was born in the UK. Since then, thousands, maybe even millions of babies have followed Louise Brown’s footsteps. In vitro fertilization (IVF) has become the most popular assisted reproduction technology (ART) for couples with fertility problems. Scientists often wondered about the health outcomes of IVF babies. Recent studies have shown that babies born through ART have higher chances of having congenital defects compared to those conceived naturally. A recent study by French researchers looked at 15,162 children born using ART from 2003 to 2007. The survey showed an abnormally high rate of congenital malformations in this population.

According to Dr. Géraldine Viot, a clinical geneticist at the Maternité Port Royal hospital, Paris, France:

“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 tumours made up of small blood vessels on or near the surface of the skin. These occurred more than twice as frequently in girls than boys.”

In addition, other relatively rare conditions such as the imprinting disorder Beckwith Wiedemann syndrome and retinoblastoma were 6 and 4.5 times higher, respectively in this group of children than in the general population.

The next step is to find out the mechanisms that bring about these abnormalities. The researchers have identified some possible culprits:

• infertility
• ovarian stimulation for multiple oocyte production
• the in vitro maturation of oocytes
• the use of ICSI (direct injection of sperm)
• the culture media used for the embryo
• cryopreservation of gametes and embryos

Dr. Viot continues:

“By following all these children we hope to understand more about not only what can go wrong after ART, but why it goes wrong. At a time when infertility is increasing and more and more couples need to use ART to conceive, it is vitally important that we find out as much as we can about what is causing malformations in these children, 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.”

They authors also emphasized that fertility specialists shoudl inform their patients of the increased risks for their children. Their results were presented at the 2010 Annual Meeting of the European Society of Human Genetics last week.