In a study scheduled for presentation Saturday at the Endocrine Society annual meeting in Houston, researchers found full-term children conceived with fertility drugs were about one inch shorter than their peers.
The researchers wanted to find out whether there was a difference in height among children whose mothers used only ovarian stimulation by fertility drugs such as Clomid (clomiphene) without in-vitro fertilization (IVF).
Children conceived with the help of ovarian stimulation alone account for about 5 percent of all births in the developed world, according to the researchers.
Previous studies have suggested that children conceived by IVF may be taller than naturally conceived kids. The researchers wanted to know if something in the process of IVF, which includes fertilization and culture of embryos in a laboratory dish, could affect stature. So they studied children conceived without IVF, but with the assistance of fertility drugs that cause ovulation.