Kids Conceived With the Aid of Fertility Drugs Are 'Shorter'
However, the study also assures that the overall physical health of such kids is not compromised.
"Reassuringly, these children remained well within the normal height range for both their sex and age," researcher Tim Savage, MD, a pediatrician and research fellow at The Liggins Institute, University of Auckland, in New Zealand, said
Because some studies have revealed that IVF-conceived children are taller than naturally conceived children, the authors focused to determine, whether there was a difference in height for children whose mothers used only fertility drugs, such as 'clomiphene' (Clomid), without in vitro fertilization (IVF).
Ovarian-stimulating fertility drugs are part of IVF, as IVF too includes fertilization and culture of embryos in a laboratory dish.
The team studied 84 children conceived with the help of fertility drugs alone and 258 children who were conceived naturally.
According to Savage, all children were from a single-fetus, full-term pregnancy and ranged in age from 3 to 10 years.
He claimed that to optimize accuracy of the study, the researchers included only children who were born at full term and did not have a low birth weight, because children born small or prematurely have an increased risk of health problems.
As a group, the fertility drug-conceived children were an average of 2 centimeters, or nearly an inch, shorter than the other children, considering their age and sex.
Savage also explained that in the statistical analysis, the researchers individually corrected the height of each child for their parents' height, because parents' height is the most important determining factor of a child's height.
However, when the groups were studied by sex, the height difference was more distinct in boys than girls.