ICSI kids become smarter than average

2019-03-02 08:11:07

By Michael Le Page, Copenhagen The first study of ICSI children at age eight suggests that children conceived this way are slightly more intelligent than normal, allaying fears that the technique is not as safe as standard IVF. ICSI – or intracytoplasmic sperm injection – involves injecting a sperm directly into the egg and is an invasive method compared with standard IVF, where sperm are simply placed with eggs and allowed to fertilise them naturally. From 1998 onwards, a few small studies reported mild developmental delays in one-year-old ICSI children compared with those conceived naturally, raising fears about the safety of the technique. But longer-term studies at age five, for example, have not found any major differences. And now Lize Leunens’ team at the Free University of Brussels (VUB) in Belgium has compared the intelligence and motor skills of 151 ICSI children at age eight with those of 153 naturally conceived children. There was no difference in motor skills, and the ICSI children scored slightly higher on intelligence tests than those conceived naturally, Leunens told a meeting of the European Society for Human Reproduction and Embryology in Copenhagen, Denmark, on Tuesday. “We can be pretty sure that in the long term these children are not suffering any developmental delays,” she says. There was no difference in the education levels of the mothers, which is known to influence children’s intelligence, so Leunens thinks the most likely explanation for the finding is that mothers of ICSI children provide more stimulation. “These mothers might be particularly dedicated to parenting,” she says. Exactly the same explanation has been proposed for the developmental delays seen in very young ICSI children. Some studies suggest that adoring ICSI mums are more likely keep their kids at home instead of sending them to playgroups, which would slightly delay their social development. But the latest study is not the final answer. Other researchers pointed out that the refusal of many parents to allow their children to take part may have skewed the results: one-third of the ICSI parents refused to participate. Leunens says that telephone interviews with these parents suggest that this made no difference to the result, but she cannot rule out the possibility. She also stresses that her team did not look at other health issues,