IVF may alter gene to make children taller

In Vitro Fertilization

Children born through in vitro fertilisation grow to be four centimetres taller as adults than their naturally conceived counterparts, according to research announced yesterday. The findings, presented to the Fertility Society of Australia's annual meeting, suggest that something during the IVF process changes the way genes are expressed, making a child grow more. The results are based on a small New Zealand study that involved single IVF births, at term, that used fresh, not frozen, embryos.

The Auckland children, aged four to 10 69 IVF and 71 non-IVF produced another surprising result: the IVF children had lower levels of "bad" cholesterol and higher levels of "good" cholesterol, which meant a lower risk of heart disease in adulthood, researcher Harriet Miles said.
Tests showed the IVF children had higher levels of growth factor in their blood and were taller for their age than the controls, more so when adjusted for parental height.
Dr Miles said the reason for the height difference was unknown. "People have different theories ... our favourite is that maybe something in the IVF process does change the expression of the genes. We wouldn't want to speculate too much because we are looking into it."
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She said researchers from the University of Auckland's Liggins Institute planned further investigations such as examining results from other IVF centres and frozen embryos "to see if they have a difference".
Dr Miles said the study was sparked by IVF sheep and cattle births, which sometimes produced large animals, and the growing link between human IVF cases and Beckwith-Wiedemann syndrome, a genetic disease that causes overgrowth.
Monash IVF medical director Gab Kovacs said the study was well designed, with a useful number of IVF subjects that needed to be followed up.

SOURCE: The Age