Effects of Physical Activity and Life-Style Factors on Uterine Contraction Frequency
Jeane Ann Grisso, Denise M. Main, Grace Chiu, Ellen Sim Synder, John H. Holmes
Clinical Epidemiology Unit, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, and Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, and Children's Hospital, San Francisco, California