IVF can make kids taller scientists

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Scientists have discovered another puzzling side-effect of IVF - that it can produce taller children.

A New Zealand-based study has found children conceived using a certain in-vitro fertilisation technique were several centimetres taller, by age 6, when compared with naturally conceived peers.

The height advantage was seen only in children born as a result of an IVF process which used fresh, and not frozen, embryos. The research adds to a growing understanding of the way different processes used in IVF, a refuge for couples with fertility problems for 30 years now, can prompt real changes in the resulting children.

"We don't know the reasons for the height difference," said Dr Mark Green, a research fellow at the Liggins Institute.

"But can I suggest that it may have something to do with the hormones that are given to the mother to stimulate the ovary in fresh embryo transfer."

Dr Green and his team measured more than 200 children, about half of them born using either fresh or frozen embryos.

Children from fresh embryos, particularly the girls, were found to be on average 2.6cm taller than their peers.

- AAP