'In Vitro Fertilization' Kids May Be Taller
Small Study Shows Height and Cholesterol Differences in Kids Conceived Through IVF
June 7, 2005 -- In a new study, children conceived through in vitro fertilization (IVF) tended to be taller and have better cholesterol than their peers who were conceived naturally.
The study, conducted in New Zealand, wasn't large, so it's not the final word on those traits. The study compared 50 children conceived through IVF with 60 naturally conceived children. All of the kids were healthy and were born without a twin or other multiples.
The results were presented in San Diego at The Endocrine Society's annual meeting. Researchers included Harriet Miles, MD, of the University of Auckland.
IVF Is 27 Years Old
It's been nearly 27 years since the first IVF baby, England's Louise Brown, was born. Since then, millions of babies have been conceived through reproductive technologies such as IVF.
However, there hasn't yet been much long-term research on children conceived through IVF, say Miles and colleagues. Almost two years ago, European experts reported that in the longest-running study to date, babies conceived through IVF and intracytoplasmic sperm injection (ICSI) didn't face more health problems than naturally conceived babies. That study included 440 babies born through IVF.
Miles and colleagues studied children who were 6 or 7 years old. A host of measurements were done, including height, bone scans, and blood tests. The researchers took into account parental height and weight.
The children conceived through IVF tended to have been born about a week earlier and at a slightly lower birth weight than their peers. They were also taller than the naturally conceived children, with the IVF girls taller than the IVF boys. However, none had hit puberty yet.
The IVF group also had a better blood fat profile. They had higher levels of HDL "good" cholesterol, lower triglyceride levels, and a trend toward lower LDL "bad" cholesterol levels, say the researchers.
No significant differences were reported in fasting insulin levels or body composition.
It could be that IVF technologies altered genes related to growth and fat regulation, says the study.