The studies by Olson et al7 and the Polley et al8 are similar to our study design in that the respective interventions are designed to encourage pregnant women to gain an amount of weight during pregnancy that is within the range recommended by the IOM. However, the intervention in the Olson et al7 study used a by-mail patient nutrition education program only and clinical guidance was given by obstetric health care providers. The Polley et al8 study intervention is similar to ours in consisting of regularly scheduled counseling by a nutritional health professional; however, the nutritional health professional was a master-level or doctoral-level student in nutrition or clinical psychology. We believe that few obstetrical offices can provide this level of nutritional instruction in clinical practice. Therefore, our study, using a single visit with a registered dietician, was designed to provide patient education and counseling in a manner that could be introduced easily and inexpensively into any obstetrical practice.