IVF may boost childhood growth and metabolism

Journal of Clinical Endocrinology and Metabolism 2007;

IVF improves childhood growth and metabolism compared with natural conception, claim researchers from New Zealand.

Harriet Miles (University of Auckland) and colleagues examined the long-term repercussions of the fertilization technique by comparing 69 IVF children aged 5.9 years with 71 naturally conceived children aged 6.9 years.

IVF children were approximately 3 cm taller than expected after correcting for parental height, with the extra height most evident in girls, the team reports.

In addition, serum insulin-like growth factor (IGF)-II levels were higher in the IVF than in the natural-conception group, at 850 versus 773 microg/l, respectively. The ratio of IGF I to IGF binding protein 3 was also higher in IVF children, and there was a trend toward higher IGF-I levels.

All children had lipid parameters within the normal range, but IVF children displayed a slightly more favourable lipid profile, with higher levels of high-density lipoprotein and lower triglyceride levels than those who were naturally conceived.

“We propose that the differences in stature, growth factors, and lipid metabolism observed in our study may be due to subtle epigenetic alteration of imprinted genes or other genes that undergo epigenetic modification that are involved in growth and development,” the researchers conclude.