NEW YORK (Reuters Health) - Children born as a result of in vitro fertilization (IVF) appear to be slightly taller than naturally conceived children, investigators in New Zealand report.
IVF has been used for nearly 3 decades, but most of the focus of research has been on pregnancy and neonatal outcomes rather than on school-age IVF children. That's probably because as babies they have few apparent problems, Dr. Wayne S. Cutfield told Reuters Health. "They are thriving, healthy children as newborns," he said.
To check up on older IVF kids, Cutfield, at the University of Auckland, and colleagues recruited healthy children aged 4 to 10 years who were born at full term. Their study included 69 children conceived by IVF using fresh embryos and 71 matched "controls" who were conceived in the normal way.
After factoring in parents' heights, the IVF children were significantly taller than their peers, by about 3 centimeters or just over an inch, the investigators report in the Journal of Clinical Endocrinology and Metabolism.
The research also suggests that hormonal profiles and lipid metabolism are slightly altered in IVF children. "Whilst we have identified differences, these are rather subtle and not obvious," Cutfield said.
Based on current evidence, he assumes that the differences they identified so far are not likely to impair the children as they grow older.
In their current work, the research team is also investigating the effect of "other artificial manipulations beyond the fresh embryos we have studied," Cutfield said, "such as use of frozen embryos."
SOURCE: Journal of Clinical Endocrinology and Metabolism, online July 12, 2007.