Children conceived with fertility drugs ‘are shorter’
The research, the first of its kind, was carried out by Cork-born Tim Savage, a paediatrician and Clinical Research Fellow at the Liggins Institute at the University of Auckland.
The findings will be published next month in the journal Human Reproduction and form part of a research project into the impact of fertility treatment and maternal age on the growth and metabolism of children.
Previous studies have indicated that children conceived with the help of IVF (in vitro fertilisation) were marginally taller than average, but no similar studies had been conducted on the possible effects of fertility drugs such as clomiphene, which have been in use since the 1960s.
Dr Savage, from Ballygarvan in Cork, said the research could not be described as conclusive.
The research, conducted in New Zealand where Dr Savage has lived for the past three years, compared the height of 84 children aged between three and 10 years of age and conceived with fertility drugs alone, with 258 children who were conceived naturally and who were in the same age group, with effort also made to match ethnicity and socio-economic backgrounds.
It found that overall the children who had been conceived using fertility drugs were on average between 2cm and 2.5cm shorter than their counterparts, considering their age, sex, and parents’ height.
Dr Savage, 38, said while the research showed children conceived with fertility drugs were shorter, they were still within the normal height range.
“Their BMI (body mass index) was slightly lower, in a healthy way,” he said. “They had a comparable cholesterol level. That is what we would have expected.
“We did assess these children with an X-ray of their hands and looking at bone maturity and they were the same as much as we can tell.”
Between 3% and 7% of children born in the US are conceived with the help of fertility medication, although the figure is likely to be smaller in Ireland.
“These children are still in the normal height range and their general health is good,” Dr Savage added. “I would hope to do further research on this in future.”
