OBJECTIVES: To establish a curve of amniotic fluid index [AFI] measurements from the 20th to the 42nd week of pregnancy. METHODS: A prospective and descriptive study was performed, in which an independent sample of 2,868 low-risk pregnant women were studied using routine ultrasound, including fetal biometry and measurement of AFI. Data were analysed using multiple linear regression, and constructing a curve using 2.5th, 10th, 50th, 90th and 97.5th percentiles of the AFI measurements, according to gestational age, and after submitting values to smoothing process using quadratic polynomial adjustment. RESULTS: There was a significant variation in AFI measurements at the different gestational ages. The 50th percentile remained practically constant at approximately 150 mm between the 20th and 33rd week, after which there was a decline in volume, which became evident after the 38th week. At the 40th week, the 10th percentile was around 62 mm and the 2.5th percentile around 33 mm. CONCLUSIONS: The curve of percentiles of AFI measurements in low-risk pregnant women showed significant decrease with gestational age, especially after the 33rd week. These data should be validated for a diagnosis of increased or decreased volumes of amniotic fluid at specific gestational ages.
OBJECTIVES: To establish a curve of amniotic fluid index [AFI] measurements from the 20th to the 42nd week of pregnancy. METHODS: A prospective and descriptive study was performed, in which an independent sample of 2,868 low-risk pregnant women were studied using routine ultrasound, including fetal biometry and measurement of AFI. Data were analysed using multiple linear regression, and constructing a curve using 2.5th, 10th, 50th, 90th and 97.5th percentiles of the AFI measurements, according to gestational age, and after submitting values to smoothing process using quadratic polynomial adjustment. RESULTS: There was a significant variation in AFI measurements at the different gestational ages. The 50th percentile remained practically constant at approximately 150 mm between the 20th and 33rd week, after which there was a decline in volume, which became evident after the 38th week. At the 40th week, the 10th percentile was around 62 mm and the 2.5th percentile around 33 mm. CONCLUSIONS: The curve of percentiles of AFI measurements in low-risk pregnant women showed significant decrease with gestational age, especially after the 33rd week. These data should be validated for a diagnosis of increased or decreased volumes of amniotic fluid at specific gestational ages.
Authors: John Owen; Paul S Albert; Germaine M Buck Louis; Karin M Fuchs; William A Grobman; Sungduk Kim; Mary E D'Alton; Ronald Wapner; Deborah A Wing; Katherine L Grantz Journal: Am J Obstet Gynecol Date: 2019-02-18 Impact factor: 8.661
Authors: Doris González-Fernández; Revathi Sahajpal; José E Chagüendo; Roberth A Ortiz Martínez; Julián A Herrera; Marilyn E Scott; Kristine G Koski Journal: Front Public Health Date: 2020-08-13