Baby-Making Secrets You Should Know

A word of warning: Because drugs of any kind can negatively affect your chances of conception and the health of your baby, check with your doctor before taking any form of medication, whether over-the-counter or prescription.

If you see a woman in the check-out line with an ovulation predictor kit and a bottle of cough syrup, you can safely assume that she isn't fighting the flu while attempting to procreate—she's actually hoping that Robitussin will make her more fertile.

"For a long time Robitussin was used by physicians and women alike to improve cervical mucus," says Deborah Metzger, MD, PhD, coauthor of Stay Fertile Longer: Everything You Need to Know to Get Pregnant Now-Or Whenever You're Ready. The theory goes like this: Guaifenesin, the chemical in Robitussin and many other cough syrups, not only thins the mucus in your lungs but will also thin the mucus in your cervix, thus creating a slippery, healthy path for sperm to swim unhindered to the awaiting egg. In fact, doctors who prescribe Clomid to fertility patients often prescribe guaifenesin at the same time because Clomid can cause thicker "hostile mucus" in some patients. However, Dr. Metzger adds that the Robitussin trick is based on a 25-year-old medical experiment, so there's not much current scientific evidence to back it up. On the other hand, she notes that it's not really harmful to try as long as you make sure the cough medicine doesn't contain antihistamines, which can dry up cervical mucus, dextromethorphan, which has been linked to birth defects, or other drugs like alcohol.