Amniotic Fluid Index (AFI) for Normal Pregnant Women in Northeastern Thailand

Objective:To construct normal reference chart of amniotic fluid volume by using the amniotic fluid index (AFI) method from 20 to 40 weeks of gestation in northeastern Thailand.Study design: A cross-sectional prospective descriptive study.Setting: Antenatal care clinic, Srinagarind Hospital, Khon Kaen University, Khon Kaen.Material and methods: All recruited 381 pregnant women with an uncomplicated singleton pregnancy from 20 to 40 weeks of gestation in northeastern Thailand from March 1, 2013 to June 30, 2014 enrolled in this study. All of them had an abdominal ultrasonography for amniotic fluid measurement using AFI method. Stat software was used to analyse the data and mean of the AFI was used in each gestational age.Main outcome measures: Normal reference chart of AFI for normal pregnancy women from 20 to 40 weeks of gestation in northeastern Thailand.Result: Mean AFI in study is 13.85 (± 3.61) cm. AFI trends to increase from GA 20 weeks to GA 29 weeks. The highest mean AFI is 15.38 cm at GA 29 weeks. Then the AFI trends to decline until GA 40 weeks. The normal reference chart of AFI was then established in this study.Conclusion: The author established normal reference chart of AFI for northeastern Thai pregnant women that can be implemented in the population of this region. The result from this study can be used to develop reference standard criteria for oligohydramnios and polyhydramnios in Thailand