An Assessment of Amniotic Fluid Index Among Japanese (A Longitudinal Study)

>Objective: To obtain a longitudinal gestational reference range for the amniotic fluid index (AFI) among Japanese women and to compare the study with those of previous reports.Methods: A total of 739 measurements of the AFI of 96 Japanese women with normal pregnancies were analyzed. The criteria were singleton pregnancies between 20 and 40 weeks, without fetal anomalies, diabetes mellitus, hypertension, and other maternal complications. Logarithmic transformation was used to obtain the predicted mean AFI values with 95% confidence intervals at each gestational week.Results: The AFI rose from 20 weeks reaching its peak at 30 weeks. After the peak, it declined toward 40 weeks. Comparison of this study with previously published reports revealed differences in the mean AFI values.Conclusions: We obtained the gestational age-specific value of AFI in normal pregnancy for Japanese women.