Department of Obstetrics and Gynecology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA. david_guzick@urmc.rochester.edu
Data on trends in fertility and infertility are of significant interest, because they may reflect social, behavioral, biological, or environmental changes. The conclusion that infertility has declined in the United States, based on data from the National Survey of Family Growth, must be interpreted with great caution because of definitional and methodologic concerns.