Age-specific nomogram for the decline in antral follicle count throughout the reproductive period

Objective: To investigate the relationship between antral follicle count (AFC) and chronological age and to establish normal values for AFC in women with regular menstrual cycles. Design: Cross-sectional study. Setting: University hospital. Patient(s): Four hundred fifteen premenopausal women were recruited for the study. Data from 362 patients were available for the statistical analysis. Intervention(s): AFC was measured by transvaginal ultrasound examination. Main Outcome Measure(s): Estimating the relationship between AFC and age and developing the AFC nomogram. Result(s): The analysis showed a linear decline in AFC with age; for every year increase in age, the median AFC decreases by 0.4. The AFC corresponding to the 5th, 25th, 50th, 75th, and 95th centiles for each age have been calculated. Conclusion(s): A linear relationship of AFC to age was found. For the first time, a nomogram reporting normal and interquartile values for AFC, age by age, throughout the reproductive period has been provided. Until now, the interpretation of the measurement was mainly based on the individual experience of the operator, because no normative data were present. Therefore, the establishment of a nomogram of AFC values is the first step to counsel patients on a scientific basis. (Fertil Steril(R) 2011;95:684-8. (C) 2011 by American Society for Reproductive Medicine.)