There is so much one can't do when going through an IVF cycle; now you can add another, breathing. Dirty air, that is.

A study reported in Science Daily and published in Human Reproduction showed exposure to an increased level of air pollutants, especially nitrogen dioxide, has been associated with lower likelihoods of successful pregnancy among women undergoing in vitro fertilization. They examined the outcomes of the first pregnancy attempt of 7,403 women undergoing IVF in Hershey, PA, Rockville, MD and New York, NY over a seven-year period from 2000 to 2007.

The main culprit appears to be nitrogen dioxide as higher nitrogen dioxide exposures consistently was associated with the lower success rate, regardless of which indictor was used — positive pregnancy test, clinically confirmed intrauterine pregnancy or live birth.

The answer to this is to have your IVF done in Redondo Beach or La Jolla, CA where the ocean breezes keep the air cleaner.