Study: IVF children are taller, have better lipid profiles.(Gynecology)

SAN DIEGO -- New Zealand school-aged children who were conceived using in vitro fertilization were taller and had more favorable lipid profiles than those conceived naturally, a case-control study concluded.

Harriet Miles, M.D., and associates at the Liggins Institute of the University of Auckland studied 50 healthy children conceived via in vitro fertilization (IVF) with fresh embryos and 60 matched controls, when the children were 7-9 years old.

Participants were singletons, born at term, she said in an oral presentation at the annual meeting of the Endocrine Society.

After controlling for midparental height, members of the IVF group were considerably taller than the naturally conceived children. "This is surprising, as 15% of the IVF group were born small for gestational age, defined as weight below the 10th percentile," said Dr. Miles, a pediatric endocrinologist.

According to standard growth prediction models, the IVF group would be up to half a standard deviation shorter than their naturally conceived peers, yet they were more than half a standard deviation taller.

"Another interesting finding is sexual dimorphism, with difference in height being more marked in females," she said.

There were no differences in body composition between the two groups of children, yet IVF-conceived children had significantly higher insulin-like growth factor I (IGF-1), IGF-II, and insulin-like growth factor-binding protein 3 (IGFBP-3).