Go ahead and ask your OB. Or the Mayo Clinic: http://www.mayoclinic.com/health/pregnancy-nutrition/PR00109/NSECTIONGROUP=2 Or the National Institute of Health: http://www.ncbi.nlm.nih.gov/pubmed/20306287. Or the American Journal of Obstetrics and Gynecology: http://www.ncbi.nlm.nih.gov/pubmed/18221932.