A recent study from Australia, published in the New England Journal of Medicine (Davies MJ et al., NEJM 2012; 366:1803-1816), suggested a 57% increase in birth defects in children born after in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI) compared with naturally conceived children. While it is well known that IVF/ICSI is associated with an increase in birth defects, the findings in the study above are alarming. Or are they?
The problem with the study above is that its authors compared birth defects rates between two groups that perrhaps should NOT be compared. It is well known that patients with infertility have a higher rate of birth defects than fertile women. A more valid comparison, therefore, would feature infertile patients vs. infertile patients undergoing IVF/ICSI. In addition, in couples undergoing IVF/ICSI for male factor, the male partner’s age tends to be older as compared with spontaneously-conceiving couples. Older male age has also been associated with an increase in birth defects.
Bottom line? The currently accepted view that IVF/ICSI is associated with slight increase in birth defects should remain unchanged. Any clinical study, especially about such a sensitive area as reproduction, must be performed responsibly and be scientifically sound, and only then it should be accepted and published by prestigious, peer-reviewed journals. Once the horse is out of the barn (as they say in my neck of the woods), it may be difficult to do damage control.
In the early 1990’s, a study suggested that clomiphene citrate, a common fertility medication, is associated with an increase in ovarian cancer. Panic ensued in the reproductive field until it became apparent that the authors compared fertile patients with infertile patients on clomiphene rather than infertile patients on or off the medication (infertile patients have an increase risk of ovarian cancer regardless of medications!) Examples like these are abound in medicine and we, as physicians, must be careful and responsible when we perform clinical studies or interpret them to our patients!