['To examine the association between obesity and serum and ultrasound measures of ovarian reserve in late reproductive age women.', 'Cross-sectional study of 36 healthy women, ages 40 to 52 years. Women were recruited in a 1:1 ratio of normal weight (body mass index <25) to obese women (body mass index >or=30). Early follicular phase blood draw, anthropometric measurements, and a transvaginal ultrasonography were performed. Outcome measures were serum antimullerian hormone, inhibin B, estradiol, follicle-stimulating hormone, ultrasound ovarian volume, and antral follicle count.', 'Mean antral follicle count was 7.6 for normal weight and 6.3 for obese women (P = 0.35). Proportions of normal weight (17%) versus obese women (22%) with antral follicle count less than 4 were similar. Ovarian volumes did not differ by body size. In adjusted models, antimullerian hormone levels in obese women were 77% lower on average than those in normal weight women (P = 0.02). Inhibin B levels were 24% lower in obese women compared with normal weight women (P = 0.08). Follicle-stimulating hormone and estradiol were not associated with body mass index.'] Does body size affect measures of ovarian reserve in late reproductive age women?