Studies that have included a focus on weight monitoring and more intensive counseling sessions have found significant effects on gestational gain. Olsen et al conducted a study that evaluated the effects of periodic weight monitoring, graphing, and education to prevent excessive weight gain during pregnancy in a sample of women from upstate New York. Results indicated that, in the lower-income women, 33% exceeded weight gain recommendations in the intervention groups, compared with 52% in the historic control group. However, no effect was found among the higher income women. Claesson et alconducted a nonrandomized evaluation of an intervention program in Sweden for obese women that included weekly 30-minute counseling sessions (focused on weight control and motivation and conducted by midwives) and weekly (1-2 times/wk) aqua aerobic classes. Results indicated that the intervention succeeded in reducing the magnitude of weight gain during pregnancy (7.5 vs 9.8 kg, respectively) and 12-week postpartum weight retention (–3.3 vs –0.52 kg, respectively), independent of socioeconomic status.