(CBS) A new study suggests that some fertility drugs may increase the risk of developing uterine cancer.
"One of the most important (drugs) that was addressed in the study is Clomiphene," Early Show medical contributor Dr. Holly Phillips told co-anchor Maggie Rodriguez Thursday. "It's also known as Clomid, and it is probably the most common fertility drug used today.
"The way Clomid works is it makes the body think its estrogen levels are lower than they actually are, and that helps with ovulation to release more eggs. That helps women become pregnant."
The study, which was done at Hadassah-Hebrew University in Jerusalem, "was significant," Phillips said, "in that it followed women for 30 years and it looked at their entire lifetime risk of developing cancers. And it did find a three-to-four time increase in uterine cancer in women who had taken this drug.
"This isn't the first time we've seen a link between things that modulate estrogen and uterine cancers, but this is one of the first times we've seen this type of link with the fertility drugs.
Still, Phillips cautioned, "previous studies have not found a link, and they've said that (fertility drugs are) completely safe, so I think what we really have to take from this is that more study is needed.