Amniotic fluid index Archives - Revista Brasileira de Ginecologia e Obstetrícia
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2003;25(9):639-646
DOI 10.1590/S0100-72032003000900004
PURPOSE: to evaluate the association between the variability of amniotic fluid index (AFI) values with gestational age and some sociodemographic and obstetric variables among low-risk pregnant women. METHOD: a comparative study was carried out including 2868 low-risk pregnant women who had routine obstetric ultrasound examination, including fetal biometry and the measurement of AFI, from 20 to 42 weeks of gestation. The data were analyzed using Student's t test, analysis of variance of mean AFI values along gestational ages, according to other control variables, and also by multiple linear regression analysis. RESULTS: there was no significant variation of mean AFI values during the time of pregnancy neither when separately evaluating its association with maternal age, color, education, smoking habit, parity, and the presence of previous cesarean section scars, nor when the evaluation was performed through multivariate analysis. In this situation only the increase in gestational age showed to be associated with the decrease of AFI. Generally speaking, the mean AFI values fluctuated between 140 and 180 mm between the 20th and the 36th week, then showing values below 140 mm in a progressive decrease after this limit of gestational age. CONCLUSIONS: AFI values do not show a significant variation during pregnancy regarding the studied sociodemographic and obstetric variables.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2003;25(9):639-646
DOI 10.1590/S0100-72032003000900004
PURPOSE: to evaluate the association between the variability of amniotic fluid index (AFI) values with gestational age and some sociodemographic and obstetric variables among low-risk pregnant women. METHOD: a comparative study was carried out including 2868 low-risk pregnant women who had routine obstetric ultrasound examination, including fetal biometry and the measurement of AFI, from 20 to 42 weeks of gestation. The data were analyzed using Student's t test, analysis of variance of mean AFI values along gestational ages, according to other control variables, and also by multiple linear regression analysis. RESULTS: there was no significant variation of mean AFI values during the time of pregnancy neither when separately evaluating its association with maternal age, color, education, smoking habit, parity, and the presence of previous cesarean section scars, nor when the evaluation was performed through multivariate analysis. In this situation only the increase in gestational age showed to be associated with the decrease of AFI. Generally speaking, the mean AFI values fluctuated between 140 and 180 mm between the 20th and the 36th week, then showing values below 140 mm in a progressive decrease after this limit of gestational age. CONCLUSIONS: AFI values do not show a significant variation during pregnancy regarding the studied sociodemographic and obstetric variables.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2000;22(9):557-566
DOI 10.1590/S0100-72032000000900004
Purpose: to study the fetal well-being assessment in pregnancies complicated by diabetes, and to analyze the neonatal results. Methods: we studied 387 pregnant women with diabetes at the Fetal Surveillance Unit. The last examination (cardiotocography, fetal biophysical profile, amniotic fluid index and dopplervelocimetry) was correlated with the neonatal outcome. Results: the studied population included 46 (12%) type I diabetes, 45 (12%) type II and 296 (76%) gestational diabetes. Type I diabetes with abnormal or suspected cardiotocography was related to abnormal 1st minute Apgar (50 and 75%, p<0.05) and to the need for neonatal intensive care unit (50 and 75%, p<0.05). The abnormal biophysical profile in type II diabetic pregnancy was related to the need for neonatal intensive care (67%, p<0.05), and abnormal umbilical artery Doppler study was related to abnormal 1st minute Apgar (67%, p<0.05). Gestational diabetes with abnormal cardiotocography presented 36% abnormal 1st minute Apgar (p<0.05), 18% abnormal 5th minute Apgar (p<0.01) and 18% neonatal death (p<0.01). Abnormal amniotic fluid index was related to abnormal 5th minute Apgar (p<0.05) and need for neonatal intensive care unit (p<0.05). Gestational diabetes with abnormal umbilical artery Doppler was related (p<0.05) to: abnormal 1st and 5th minute Apgar, respectively, 25 and 8%, Need for neonatal intensive care in 17% and neonatal death in 8%. Conclusions: the fetal well-being examinations correlated with adverse perinatal outcome, showing the need for fetal surveillance in diabetic pregnant women.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2000;22(9):557-566
DOI 10.1590/S0100-72032000000900004
Purpose: to study the fetal well-being assessment in pregnancies complicated by diabetes, and to analyze the neonatal results. Methods: we studied 387 pregnant women with diabetes at the Fetal Surveillance Unit. The last examination (cardiotocography, fetal biophysical profile, amniotic fluid index and dopplervelocimetry) was correlated with the neonatal outcome. Results: the studied population included 46 (12%) type I diabetes, 45 (12%) type II and 296 (76%) gestational diabetes. Type I diabetes with abnormal or suspected cardiotocography was related to abnormal 1st minute Apgar (50 and 75%, p<0.05) and to the need for neonatal intensive care unit (50 and 75%, p<0.05). The abnormal biophysical profile in type II diabetic pregnancy was related to the need for neonatal intensive care (67%, p<0.05), and abnormal umbilical artery Doppler study was related to abnormal 1st minute Apgar (67%, p<0.05). Gestational diabetes with abnormal cardiotocography presented 36% abnormal 1st minute Apgar (p<0.05), 18% abnormal 5th minute Apgar (p<0.01) and 18% neonatal death (p<0.01). Abnormal amniotic fluid index was related to abnormal 5th minute Apgar (p<0.05) and need for neonatal intensive care unit (p<0.05). Gestational diabetes with abnormal umbilical artery Doppler was related (p<0.05) to: abnormal 1st and 5th minute Apgar, respectively, 25 and 8%, Need for neonatal intensive care in 17% and neonatal death in 8%. Conclusions: the fetal well-being examinations correlated with adverse perinatal outcome, showing the need for fetal surveillance in diabetic pregnant women.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2001;23(4):225-232
DOI 10.1590/S0100-72032001000400005
Purpose: to determine the amniotic fluid index (AFI) through ultrasound assessment in normal pregnancies and produce a curve of normalcy for the AFI from the 12th up to the 42nd week of pregnancy. Methods: the study involved 471 measurements on 256 pregnant women, all undergoing normal pregnancies. In pregnancies of more than 20 weeks an estimation was made of the sum of the largest vertical diameters of the amniotic fluid pockets in the four quadrants into which the uterus was divided. In the pregnancies of 20 weeks or less, the sum was obtained from the largest vertical diameters measured in the two halves into which the uterus was divided. Results were expressed in centimeters. Results: AFI was measured (471 measurements) and the results were stratified and grouped by weeks of pregnancy (every two weeks), except the 12th week which was analyzed alone. From an average of 4.7 cm (limits 3.8-5.9 for the 5th and the 95th percentiles) at the 12th week of pregnancy, the AFI grew progressively up to the maximum mean of 14.6 cm at the 32nd week (limits: 7.0-2.5 cm). AFI presented stable measurements from the 21st up to the 40th week. After that, AFI measurements suffered a sharp decrease. The AFI cutoff point occurred at the 21st week of pregnancy. The percent increase of AFI obtained at the 32nd week, when compared to the 12th was 197.7%, and 2.9% at the end of pregnancy when compared to the measurement of the week taken as reference. Conclusion: AFI varied during pregnancy. It increased progressively up to the 21st week and then stabilized up to the 40th week. After that, it experienced a sharp decline. The maximum measurement of the AFI occurred at the 32nd week. By establishing a normalcy curve for AFI it becomes easier to detect changes and allows for a better follow-up of the pregnancy period.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2001;23(4):225-232
DOI 10.1590/S0100-72032001000400005
Purpose: to determine the amniotic fluid index (AFI) through ultrasound assessment in normal pregnancies and produce a curve of normalcy for the AFI from the 12th up to the 42nd week of pregnancy. Methods: the study involved 471 measurements on 256 pregnant women, all undergoing normal pregnancies. In pregnancies of more than 20 weeks an estimation was made of the sum of the largest vertical diameters of the amniotic fluid pockets in the four quadrants into which the uterus was divided. In the pregnancies of 20 weeks or less, the sum was obtained from the largest vertical diameters measured in the two halves into which the uterus was divided. Results were expressed in centimeters. Results: AFI was measured (471 measurements) and the results were stratified and grouped by weeks of pregnancy (every two weeks), except the 12th week which was analyzed alone. From an average of 4.7 cm (limits 3.8-5.9 for the 5th and the 95th percentiles) at the 12th week of pregnancy, the AFI grew progressively up to the maximum mean of 14.6 cm at the 32nd week (limits: 7.0-2.5 cm). AFI presented stable measurements from the 21st up to the 40th week. After that, AFI measurements suffered a sharp decrease. The AFI cutoff point occurred at the 21st week of pregnancy. The percent increase of AFI obtained at the 32nd week, when compared to the 12th was 197.7%, and 2.9% at the end of pregnancy when compared to the measurement of the week taken as reference. Conclusion: AFI varied during pregnancy. It increased progressively up to the 21st week and then stabilized up to the 40th week. After that, it experienced a sharp decline. The maximum measurement of the AFI occurred at the 32nd week. By establishing a normalcy curve for AFI it becomes easier to detect changes and allows for a better follow-up of the pregnancy period.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2001;23(2):101-105
DOI 10.1590/S0100-72032001000200007
Purpose: to study the changes in amniotic fluid index (AFI) measured by ultrasonography, mean arterial pressure (MAP) and pulse rate in normal pregnant women submitted to subtotal body immersion in water for different periods of time, and to standardize the technique. Methods: AFI values were studied as recommended by Phelan et al.¹ in a group of 52 pregnant women with gestational age of 28 weeks or more considered to be clinically normal, before and after exposure to subtotal immersion in water heated to 32 to 34ºC for 30, 45 and 60 min. The patients were seen at the Ultrasonography and Medical Updating School of Ribeirão Preto and in the Department of Gynecology and Obstetrics of the Faculty of Medicine of Ribeirão Preto, University of São Paulo. Results: before and after immersion, the average of MAP was 87.8 and 87.1 in the group of 30 min, 76.7 and 66.6 in the group of 45 min and 77.4 and 60.7 in the group of 60 min, with statistical significance. Before and after immersion, the means of pulse rates were 74.9 and 78.7 in the group of 30 min, 83.6 and 85.2 in the group of 45 min and 84.9 and 90.6 in the group of 60 min, with statistical significance. The mean of AFI also showed statistical significance. When submitted to 30-min immersion the means of AFI were 11.7 cm before and 16.8 cm after. In the group of 45 min, the averages were 9.7 cm before and 13.8 cm after immersion. In the group of 60 min, the averages were 9.5 cm before and 13.6 cm after immersion. The time of immersion of 30-min was as effective and ample as 45 or 60 min. Conclusions: subtotal immersion in water is a safe and practical procedure that can mobilize fluids during pregnancy, increasing amniotic fluid volume.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2001;23(2):101-105
DOI 10.1590/S0100-72032001000200007
Purpose: to study the changes in amniotic fluid index (AFI) measured by ultrasonography, mean arterial pressure (MAP) and pulse rate in normal pregnant women submitted to subtotal body immersion in water for different periods of time, and to standardize the technique. Methods: AFI values were studied as recommended by Phelan et al.¹ in a group of 52 pregnant women with gestational age of 28 weeks or more considered to be clinically normal, before and after exposure to subtotal immersion in water heated to 32 to 34ºC for 30, 45 and 60 min. The patients were seen at the Ultrasonography and Medical Updating School of Ribeirão Preto and in the Department of Gynecology and Obstetrics of the Faculty of Medicine of Ribeirão Preto, University of São Paulo. Results: before and after immersion, the average of MAP was 87.8 and 87.1 in the group of 30 min, 76.7 and 66.6 in the group of 45 min and 77.4 and 60.7 in the group of 60 min, with statistical significance. Before and after immersion, the means of pulse rates were 74.9 and 78.7 in the group of 30 min, 83.6 and 85.2 in the group of 45 min and 84.9 and 90.6 in the group of 60 min, with statistical significance. The mean of AFI also showed statistical significance. When submitted to 30-min immersion the means of AFI were 11.7 cm before and 16.8 cm after. In the group of 45 min, the averages were 9.7 cm before and 13.8 cm after immersion. In the group of 60 min, the averages were 9.5 cm before and 13.6 cm after immersion. The time of immersion of 30-min was as effective and ample as 45 or 60 min. Conclusions: subtotal immersion in water is a safe and practical procedure that can mobilize fluids during pregnancy, increasing amniotic fluid volume.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2002;24(2):113-120
DOI 10.1590/S0100-72032002000200007
Purpose: to study fetal surveillance examinations in pregnancies complicated by pregestational diabetes mellitus, and to correlate them with large for gestational age (LGA) newborns. Methods: Between March 1999 and June 2001, 46 singleton pregnancies with pregestational diabetes mellitus without fetal anomalies were followed prospectively. From the 28th gestational week on, the following examinations were performed weekly: fetal biophysical profile, amniotic fluid index (AFI), and dopplervelocimetry of umbilical and middle cerebral arteries. The newborns with birthweight above the 90th percentile according to local standard values were characterized as LGA infants. Fisher's exact test and Student's t test were used for statistical analysis. Results: The mean gestational age at delivery was 37.6 weeks and 15 (32.6%) newborns were LGA. LGA fetuses showed significant increase in the AFI mean performed in the 32nd (16.5 cm, p=0.02), 33rd (16.7 cm, p=0.03), 34th (17.0 cm, p=0.02), 35th (17.9 cm, p=0.000), 36th (15.8 cm, p=0.03) and 37th (17.5 cm, p=0.003) weeks. Non-LGA fetuses presented the following mean AFI values: 13.5cm (32nd week), 13.1cm (33th week), 13.4 (34th week), 12.8 (35th week), 12.5 (36th week) and 12.8cm (37th week). AFI values equal to or above 18.0 cm were associated with the occurrence of LGA infants, when detected at the following gestational ages: 34th (60%, p=0.03), 35th (71.4%, p=0.01), 36th (80%, p=0.02) and 37th (66.7%, p=0.04) week. Non-LGA infants presented the following proportion of AFI values equal to or above 18.0 cm: 40.0% (34th week), 28.6% (35th week), 20.0% (36th week), and 33.3% (37th week). Conclusions: abnormal increase in AFI, mainly with values equal to or above 18.0 cm, is related to LGA infants at delivery. The maternal treatment should be adjusted to achieve the best result for maternal-fetal control, according to the AFI values during pregnancy.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2002;24(2):113-120
DOI 10.1590/S0100-72032002000200007
Purpose: to study fetal surveillance examinations in pregnancies complicated by pregestational diabetes mellitus, and to correlate them with large for gestational age (LGA) newborns. Methods: Between March 1999 and June 2001, 46 singleton pregnancies with pregestational diabetes mellitus without fetal anomalies were followed prospectively. From the 28th gestational week on, the following examinations were performed weekly: fetal biophysical profile, amniotic fluid index (AFI), and dopplervelocimetry of umbilical and middle cerebral arteries. The newborns with birthweight above the 90th percentile according to local standard values were characterized as LGA infants. Fisher's exact test and Student's t test were used for statistical analysis. Results: The mean gestational age at delivery was 37.6 weeks and 15 (32.6%) newborns were LGA. LGA fetuses showed significant increase in the AFI mean performed in the 32nd (16.5 cm, p=0.02), 33rd (16.7 cm, p=0.03), 34th (17.0 cm, p=0.02), 35th (17.9 cm, p=0.000), 36th (15.8 cm, p=0.03) and 37th (17.5 cm, p=0.003) weeks. Non-LGA fetuses presented the following mean AFI values: 13.5cm (32nd week), 13.1cm (33th week), 13.4 (34th week), 12.8 (35th week), 12.5 (36th week) and 12.8cm (37th week). AFI values equal to or above 18.0 cm were associated with the occurrence of LGA infants, when detected at the following gestational ages: 34th (60%, p=0.03), 35th (71.4%, p=0.01), 36th (80%, p=0.02) and 37th (66.7%, p=0.04) week. Non-LGA infants presented the following proportion of AFI values equal to or above 18.0 cm: 40.0% (34th week), 28.6% (35th week), 20.0% (36th week), and 33.3% (37th week). Conclusions: abnormal increase in AFI, mainly with values equal to or above 18.0 cm, is related to LGA infants at delivery. The maternal treatment should be adjusted to achieve the best result for maternal-fetal control, according to the AFI values during pregnancy.
