Side effects of Clomid and other fertility treatments have been associated with an increased risk of birth defects, according to the findings of a recent study.
Australian researchers focusing primarily on in vitro fertilization (IFV) and intracytoplasmic sperm injection (ICSI) types of assisted contraception and the rate of birth defects linked to those techniques, found that birth defects linked to the use of Clomid surpassed any linked to any other drug. The findings of their study were published last week in the New England Medical Journal.
Researchers looked at births and fertility treatment use in South Australia from January 1986 through December 2002. While there was an increased risk of birth defects among all forms of fertility treatment, IVF resulted in a 25% increase, while ICSI was linked to a 72% overall increase in the rate of birth defects. However, for prospective mothers given the drug Clomid, the risk jumped to about 300%.
The number of actual cases where Clomid resulted in birth defects was very small, cautioned the researchers, but their findings provide support for previous studies.
Determining the true cause of birth defects in children conceived through assisted means is often difficult. For years, researchers have been trying to determine whether side effects of Clomid may increase the risk of birth defects, particularly neural tube defects (NTDs).
The FDA has received hundreds of post-marketing reports of Clomid birth defects since it was first approved in 1972. Some studies suggest the use of the drug as much as tripled the risk of birth defects when compared to women who conceived normally. However a number of other studies have found weaker or no associations.
Neural tube birth defects occur when the neural tube does not close completely, leaving an opening in the spinal cord or brain. This could result in spina bifida, anencephaly, as well as others birth defects.