Amniotic Fluid Index Measurements Research Articles

Abnormal liquor volume and mode of delivery

Introductions: Sonographic assessment of four quadrant measurement of amniotic fluid index (AFI) is an integral part of antenatal evaluation of pregnancies, especially in the third trimester. Decreased (oligohydramnios, AFI 0-9.9 cm) or increased (polyhydramnios >25 cm) increases the risk of intrauterine growth retardation, birth asphyxia and induction or operative interference. The aim of this study was to analyse abnormal liquor volume and mode of delivery.
 Methods: This retrospective cross-sectional study analysed the cases of abnormal liquor volume in term pregnancies during 2013-2016 at Patan Hospital. Patient's files were traced from medical record section. We analysed the abnormal liquor volume based on amniotic fluid index (AFI) and the mode of deliveries.
 Results: Among 15,272 term pregnancies scanned, 130 had abnormal AFI, 128 oligohydramnios and 2 polyhydramnios. Out of 128 oligohydramnios, 40 (30.8%) were severe, 54 (41.5%) moderate and 34 (26.2%) mild. Two cases had polyhydramnios. The emergency lower uterine segment caesarean sections (emLSCS) were performed in 99 (76.1%) oligohydramnios.
 Conclusions: This study suggests that oligohydramnios measured by AFI at term pregnancy required more emLSCS.

Amniotic Fluid Index Curves in the Obese Gravida: One Size Fits All? [36P

INTRODUCTION: The purpose of this study was to evaluate whether amniotic fluid index (AFI) curves differed based on maternal body mass index (BMI) category. METHODS: This was a retrospective cohort study of 500 pregnant women receiving ultrasounds with AFI measurements. The study cohort was subdivided by maternal intake BMI into three groups: normal weight (18.5-24.9), overweight (25.0-29.9) and obese (>30). Demographic and outcome data were evaluated with chi square for dichotomous variables and ANOVA or Kruskal-Wallis on continuous variables as appropriate. Linear regression was used to evaluate AFI over gestation in each group and analysis of covariance was used to evaluate AFI over gestation between groups. RESULTS: There was no correlation between AFI and gestational age in each group (normal weight (R=.055), overweight (R=.161), obese (R=.018) or as an aggregate (R=.06)). However, there was a difference in AFI over gestation between groups (F (2,1740) = 9.96, P<.001). Both, pre-existing diabetes (P=.002) and chronic hypertension (P<.001), were more prevalent in obese gravida. Obese gravida were more likely to develop gestational diabetes (P<.001). Development of pregnancy hypertensive disorders did not vary between BMI groups (P=.145). Mean gestational age of delivery was similar between groups (P=.266); however, infant birth-weight increased with increasing maternal intake BMI (P=.040). CONCLUSION: In this cohort, there is a difference in AFI based on maternal BMI when accounting for gestational age. While the absolute difference in our cohort was small, this finding suggests we should evaluate this question on a larger scale and potentially re-visit a “one size fits all” approach to AFI.

EFFECTIVENESS OF UMBILICAL ARTERY DOPPLER EXAMINATION, CARDIOTOCOGRAPHY AND AMNIOTIC FLUID INDEX APPLIED IN EARLY INTRAPARTUM PERIOD IN DIAGNOSIS OF FETAL DISTRESS

The present study aims to find an alternative solution to continuous monitoring with Cardiotocography (CTG) during intrapartum management process of pregnant women with no previous antenatal follow-up, and to diagnose low-risk pregnancies and avoid the financial burden and discomfort to the pregnant woman resulting from continuous monitoring. Randomly selected 114 term pregnant women with expected vaginal delivery, singleton pregnancies and no major fetal abnormalities were included in the study. Routine obstetric ultrasonography (USG) and uterine artery (UA) doppler measurements were administered. The pregnant women included in the study had an average gestation period of 38.3 ± 1.3, average age of 26.1 ± 5.3, average parity of 2.1 ± 1.5 and average infant birth weight of 3280 ± 442 g. 13 pregnant women were considered to have fetal distress following continuous monitoring with cardiotocography. Furthermore, decreased amniotic fluid index was detected in 9 of them. 10 cases were assessed to be pathological as a result of Uterine Artery Doppler examination. In two cases deemed pathological, fetal distress developed and found to be statistically insignificant. No statistically significant difference was found between decreased amniotic fluid index cases and non-decreased amniotic fluid index cases in terms of C-section application due to fetal distress. In our study, Cardiotocography + Amniotic Fluid Index measurement was determined to be the most valuable combination as the delivery room admission test.

Does Obesity Affect the Assessment of Third Trimester Amniotic Fluid? [1P

INTRODUCTION: To determine the inter-observer and intra-observer variability of amniotic fluid index (AFI) and maximum vertical pocket (MVP) measurements in obese pregnant women compared to non-obese pregnant. METHODS: This is a prospective study of women presenting for scheduled 3rd trimester clinically indicated ultrasound. AFI and MVP were measured by two sonographers. The first sonographer collected each measurement twice to assess intra-observer variability. The second sonographer was blinded to the measurement of the first sonographer to provide the measurement of inter-observer variability. Both measures of variability were estimated using the intra-class correlation (ICC) with 95% confidence intervals, ICC of 0.4 was considered the minimally accepted level of variability. All analyses were done using SAS 9.4®. RESULTS: Of the 126 patients enrolled, there was a mean maternal age of 33.8±5.5 years, mean BMI of 29.1±7.1 kg/m2 and mean gestational age 32.9±0.9 weeks. At that time, 57.8% of the patients were obese, 20.6% of the patients were affected by gestational diabetes, and 19% of the patients had prior cesarean section. The mean BMI for obese patients was 36.9±5.6 kg/m2 and for non-obese 26.5±2.8 kg/m2. ICC and 95% CI are presented for the overall cohort, as well as obese and non-obese women. CONCLUSION: Intra-observer variability for both MVP and AFI were acceptable in obese and non-obese women. Inter-observer correlation was poor, particularly when MVP was assessed in both obese and non-obese women. Obesity does not appear to have a significant impact on the variability of amniotic fluid assessment in the third trimester.

Accuracy of Amniotic Fluid Index and Single Deepest Pocket Measurement in Predicting of Postdate Pregnancy Outcomes

Accuracy of Amniotic Fluid Index and Single Deepest Pocket Measurement in Predicting of Postdate Pregnancy Outcomes

Multiple ultrasonographic parameters and fetal fibronectin measurement for prediction of preterm labor at risk

Objective The present study was conducted to evaluate cervical length measurement, placental score, and amniotic fluid volume by ultrasound, and the level of fetal fibronectin (FFN) between 24 and 34 weeks of gestation as predictors of preterm labor. Background Spontaneous preterm birth continues to be the major contributor to perinatal morbidity and mortality. Early detection of preterm labor is difficult because initial symptoms and signs are often mild and may occur in normal pregnancy. The traditional criteria for preterm labor (persistent contractions accompanied by progressive cervical dilatation and effacement) are most accurate. Other means have been thought to detect preterm labor early. These include ultrasound examination of the cervix to measure the cervical length, measurement of amniotic fluid index, and detection of FFN in the cervicovaginal sample. Patients and methods This study was carried out on 80 pregnant women attending the antenatal care clinic of Kafr El-Dwar General Hospital from July 2014 to April 2015. The patients were divided into two groups: group one (50 cases), which included patients who have no history of unexplained preterm labor, and group two (30 cases), which included patients who have a history of unexplained preterm labor. Patients were followed up for the occurrence of preterm labor pain. Full complete history was taken from all cases, and then general examination was done for them. FFN testing and transabdominal and transvaginal ultrasound examination between 24 and 34 weeks of gestation with assessment of cervical length, fetal viability, number, fetal biometry (biparietal diameter, femur length, abdominal circumference), placenta (score, site, and maturity), and amniotic fluid (amount and turbidity) were performed. Results The results of this study revealed that the risk of preterm delivery (PTD) is inversely correlated with cervical length. Routine transvaginal scan of the cervix performed between 24 and 34 weeks helped to identify patients at risk of PTD; women with oligohydramnios are found to be liable to develop preterm labor. Assay of FFN in cervicovaginal secretions has proven to be a valuable test in the prediction of spontaneous PTD. Conclusion The first step in the prevention of preterm labor is early identification of women at risk for preterm birth by the use of ultrasonography to detect cervical length and amniotic fluid volume and by the detection of FFN in cervicovaginal secretion.

238: Updating amniotic fluid index nomogram according to perinatal outcome

The two most commonly used nomograms defining Amniotic Fluid Index (AFI) are by: 1) Moore and Cayle and 2) Megann. These nomograms differ in defining normal (5th to 95th percentiles) and abnormal AFI. We aimed to evaluate whether these differences carries clinical significance and define new thresholds for AFI measurements. A retrospective cohort study of all women with singleton pregnancies evaluated for AFI during pregnancy, and delivered in a university-affiliated hospital (2007-2016). The cohort was divided to 5 groups according to AFI: group A - below 5th percentile in both nomograms defined as definite oligohydramnious; group B - below 5th percentile only in the first nomogram (Moore's) defined as intermediate oligoydramnious; group C - normal AFI defined by both nomograms; group D - above 95th percentile only in the second nomogram (Megann's) defined as intermediate polyhydramnious; group E - above 95th percentile in both nomograms defined as definite polyhydramnious. 1) 6987 pregnancies were identified: group A 996(14%), group B 1344(19%), group C 2561(37%), group D 1051(15%) and group E 1034(15%). 2) Comparing group B to A and C revealed the following (Table 1): Patients in group A delivered earlier than group B (37.19 vs. 38.65 p<0.001). Regarding perinatal outcome, group B differed from group A by lower rates of: small for gestational age (12.3 vs. 15.2%, p=0.05), neonatal intensive care unit admission (11.1 vs. 21.5%, p<0.001), respiratory composite outcome (4.8 vs. 9.8% p< 0.001), neonatal sepsis (6.4 vs. 10.8%, p<0.001) and more. No such differences were found between groups B and C. 3) Comparing group D to C and E revealed the following (Table 2): Groups were clinically comparable in baseline characteristics. Patients in group D presented the highest rates of gestational diabetes (18.9 vs. 10.3% in group C, p<0.001 and 15.7% in group E, p=0.063). Regarding perinatal outcome, group D differed from group E by lower rates of: 5 minutes Apgar score<7 (1.3 vs. 3.2% p=0.003), NICU admission (10.9 vs. 14.4%, p=0.02) and major fetal anomalies (1.7 vs. 5.6%, p=0.02). The same parameters did not differ between groups D and C. Commonly used AFI nomograms should be updated. Intermediate oligo and polyhydramnious are not related to adverse neonatal outcomes and are similar in neonatal outcome to patients with euhydramnious.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Single deepest vertical pocket or amniotic fluid index as evaluation test for predicting adverse pregnancy outcome (SAFE trial): a multicenter, open-label, randomized controlled trial.

To determine whether the amniotic fluid index (AFI) or the single deepest vertical pocket (SDP) technique for estimating amniotic fluid volume is superior for predicting adverse pregnancy outcome. This was a multicenter randomized controlled trial including 1052 pregnant women with a term singleton pregnancy across four hospitals in Germany. Women were assigned randomly, according to a computer-generated allocation sequence, to AFI or SDP measurement for estimation of amniotic fluid volume. Oligohydramnios was defined as AFI ≤ 5 cm or the absence of a pocket measuring at least 2 × 1 cm. The diagnosis of oligohydramnios was followed by labor induction. The primary outcome measure was postpartum admission to a neonatal intensive care unit. Further outcome parameters were the rates of diagnosis of oligohydramnios and induction of labor (for oligohydramnios or without specific indication), and mode of delivery. Postpartum admission to a neonatal intensive care unit was similar between groups (4.2% (n = 21) vs 5.0% (n = 25); relative risk (RR), 0.85 (95% CI, 0.48-1.50); P = 0.57). In the AFI group, there were more cases of oligohydramnios (9.8% (n = 49) vs 2.2% (n = 11); RR, 4.51 (95% CI, 2.2-8.57); P < 0.01) and more cases of labor induction for oligohydramnios (12.7% (n = 33) vs 3.6% (n = 10); RR, 3.50 (95% CI, 1.76-6.96); P < 0.01) than in the SDP group. Moreover, an abnormal cardiotocography was seen more often in the AFI group than in the SDP group (32.3% (n = 161) vs 26.2% (n = 132); RR, 1.23 (95% CI, 1.02-1.50); P = 0.03). The other outcome measures were not significantly different between the two groups. Use of the AFI method increased the rate of diagnosis of oligohydramnios and labor induction for oligohydramnios without improving perinatal outcome. The SDP method is therefore the favorable method to estimate amniotic fluid volume, especially in a population with many low-risk pregnancies. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

The Influence of Fasting in Summer on Amniotic Fluid During Pregnancy.

Objectives:Ramadan is a holy month in which eating and drinking are forbidden from dawn to sunset. In this study, we investigated using ultrasonography (USG) whether fasting in summer (as occurred in Ramadan 2014) had an influence on the volume of amniotic fluid during pregnancy.Materials and Methods:The study included 119 pregnant women in total who were admitted to our department with a request of obstetric USG between June 28, 2014, and July 27, 2014. The fasting group included 61 pregnant women and the control group of 58 pregnant women. In our study, all the fasting pregnant women had Sahur (predawn meal eaten before starting fasting) and Iftar (the evening meal for fast-breaking) every day, regularly. The women in the control group did not fast. In addition to amniotic fluid index and fetal biometric measurements during Ramadan, amniotic fluid volume was measured ultrasonographically throughout pregnancy. All ultrasound examinations were performed at least 8 h after Sahur during Ramadan. Chi-square test was utilized to compare the measurements of amniotic fluid volume, and Mann–Whitney U-test was utilized to analyze the differences in fetal growth data. Moreover, difference was considered statistically significant when the P value was <0.05.Results:The mean age was 25.7 years in the fasting group and 25.8 years in the control group. Other characteristics and mean gestational weeks of the two groups were similar. Ultrasonographically, there was no significant difference between two groups in respect to amniotic fluid amount during pregnancy (P = 0.7). There was no significant difference with regard to fetal growth parameters either (P > 0.05).Conclusion:In pregnant women who had regular predawn and fast-breaking meals, fasting in summer did not elicit alteration in the amount of amniotic fluid throughout pregnancy.

Idiopathic Polyhydramnios: Severity and Perinatal Morbidity.

Objective To estimate the association between the severity of idiopathic polyhydramnios and adverse outcomes. Study Design Retrospective cohort study of deliveries at one hospital from 2000 to 2012 with an amniotic fluid index (AFI) measurement ≥24 + 0 weeks' gestation. Pregnancies complicated by diabetes, multiples, or fetal anomalies were excluded. Exposure was the degree of polyhydramnios: normal (AFI 5-24 cm), mild (≥ 24-30 cm), and moderate-severe (> 30 cm). Primary outcomes were perinatal mortality, neonatal intensive care unit (NICU) admission, and postpartum hemorrhage. Results There were 10,536 pregnancies: 10,188 with a normal AFI, 274 mild (78.74%), and 74 moderate-severe polyhydramnios (21.26%). Adverse outcomes were increased with idiopathic polyhydramnios: NICU admission (adjusted odds ratio [AOR] 3.71, 95% confidence interval [CI] 2.77-4.99), postpartum hemorrhage (AOR 15.81, 95% CI 7.82-31.96), macrosomia (AOR 3.41, 95% CI 2.61-4.47), low 5-minute Apgar score (AOR 2.60, 95% CI 1.57-4.30), and cesarean (AOR 2.16, 95% CI 1.74-2.69). There were increasing odds of macrosomia (mild: AOR 3.19, 95% CI 2.36-4.32; moderate-severe: AOR 4.44, 95% CI 2.53-7.79) and low 5-minute Apgar score (mild: AOR 2.24, 95% CI 1.23-4.08; moderate-severe: AOR 3.93, 95% CI 1.62-9.55) with increasing severity of polyhydramnios. Conclusion Idiopathic polyhydramnios is independently associated with increased risks of morbidity. There appears to be a dose-response relationship for neonatal macrosomia and low 5-minute Apgar score risks.

Unconditional reference values for the amniotic fluid index measurement between 26w0d and 41w6d of gestation in low-risk pregnancies

Objective: To establish reference values for the amniotic fluid index (AFI) measurement between 26w0d and 41w6d of gestation in a Brazilian population.Methods: We performed a cross-sectional study with 1984 low-risk singleton pregnant women between 26w0d and 41w6d of gestation. AFI was measured according to the technique proposed by Phelan et al. Maternal abdomen was divided into four quadrants using the umbilicus and linea nigra as landmarks. Single vertical pocket in each quadrant was measured and the AFI was generated by the sum of these four values without umbilical cord or fetal parts. All ultrasound exams were performed by only two experienced examiners. AFI was expressed as median, interquartile range, mean and ranges in each gestational age (GA) interval. Polynomial regressions were performed to obtain the best fit with adjustment by the determination coefficient (R2).Results: Mean of AFI ranged from 14.0 ± 4.1 cm (range, 9.7–14.0) at 26w0d to 8.3 ± 4.7 cm (range, 1.9–16.5) at 41w6d, respectively. The best polynomial regression fit curve was a first-degree: AFI = 16.29–0.125*GA (R2 = 0.01). According the scatterplot, AFI values practically did not vary with advancing GA.Conclusion: Reference values for the AFI measurement between 26w0d and 41w6d of gestation in a low-risk Brazilian population were established.

Ultrasound biometry of normal human amniotic fluid index in a Nigerian population

BackgroundThe amniotic fluid index (AFI) closely represents the actual amniotic fluid volume (AFV) with measurements below and above the 5th and 95th percentiles describing oligohydramnios and polyhydramnios respectively. ObjectiveTo create a sonographic reference range nomogram of the AFI for a Nigerian population using polynomial regression, and to test for reproducibility of AFI measurements. MethodsFive hundred and sixty patients between 16 and 40 weeks fetal gestational age (FGA) were sampled for the study. The FGA was estimated sonographically by combining the fetal biparietal diameter, abdominal circumference, and femoral length measurements. The AFI was obtained by measuring and summing up the deepest pool of amniotic fluid devoid of fetal parts and umbilical cord in each quadrant of the maternal abdomen. To test for reproducibility of AFI measurements, two sonographers with more than 8 years of obstetric clinical experience independently measured the AFI of 40 patients. Polynomial regression, Pearson's correlation, and intra class correlations were used for data analysis. ResultsThe mean ± SD of the AFI obtained in the second and third trimester respectively is 15.2 ± 4.0 cm, and 16.0 ± 5.8 cm. There was a steady but insignificant decrease in the AFI at all the FGA studied. A log transformed linear model adequately fitted the relationship between the AFI and FGA, given as: AFIcm=1.1461+0.00091×FGA(R2=0.002). Our normal AFI range is from 8.6 cm to 27.0 cm. ConclusionOligohydramnios and polyhydramnios can be satisfactorily diagnosed in the study population when AFI measurement is below or above 8.6 cm and 27.0 cm respectively.

Reproducibility of measuring amniotic fluid index and single deepest vertical pool throughout gestation.

The aim of this study is to assess the intraobserver and interobserver reproducibility of measurement of amniotic fluid index (AFI) and single deepest vertical pool (SDVP), also known as the maximal vertical pocket. A total of 175 fetuses were evaluated. For each fetus, two observers acquired duplicate sets of AFI and SDVP. Measurement differences were expressed as actual and percentage values. For all comparisons, Bland-Altman plots were used to compare differences, and limits of agreement were calculated. Intraobserver and interobserver agreement remained fairly constant with gestation, both for AFI and SDVP. The intraobserver limits of agreement for AFI were -5.2 to 5 cm or -39% to 37%; whereas for SDVP, these were -2.6 to 2.4 cm or -52% to 48%. The interobserver limits of agreement for AFI measurement were -7.3 to 7.1 cm or -54% to 53% and for SDVP measurement were -2.5 to 2.5 cm or -51% to 52%. Intraobserver coefficient of variation for SDVP was 14% and for AFI was 19%; the interobserver coefficient was 19% for both AFI and SDVP. Limits of agreement for both methods are wide. The choice of method should be dictated by clinical considerations other than method reproducibility.

Reference ranges of amniotic fluid index in late third trimester of pregnancy: what should the optimal interval between two ultrasound examinations be?

Background. Amniotic fluid index (AFI) is one of the major and deciding components of fetal biophysical profile and by itself it can predict pregnancy outcome. Very low values are associated with intrauterine growth restriction and renal anomalies of fetus, whereas high values may indicate fetal GI anomalies, maternal diabetes mellitus, and so forth. However, before deciding the cut-off standards for abnormal values for a local population, what constitutes a normal range for specific gestational age and the ideal interval of testing should be defined. Objectives. To establish reference standards for AFI for local population after 34 weeks of pregnancy and to decide an optimal scan interval for AFI estimation in third trimester in low risk antenatal women. Materials and Methods. A prospective estimation of AFI was done in 50 healthy pregnant women from 34 to 40 weeks at weekly intervals. The trend of amniotic fluid volume was studied with advancing gestational age. Only low risk singleton pregnancies with accurately established gestational age who were available for all weekly scan from 34 to 40 weeks were included in the study. Women with gestational or overt diabetes mellitus, hypertensive disorders of the pregnancy, prelabour rupture of membranes, and congenital anomalies in the foetus and those who delivered before 40 completed weeks were excluded from the study. For the purpose of AFI measurement, the uterine cavity was arbitrarily divided into four quadrants by a vertical and horizontal line running through umbilicus. Linear array transabdominal probe was used to measure the largest vertical pocket (in cm) in perpendicular plane to the abdominal skin in each quadrant. Amniotic fluid index was obtained by adding these four measurements. Statistical analysis was done using SPSS software (Version 16, Chicago, IL). Percentile curves (5th, 50th, and 95th centiles) were constructed for comparison with other studies. Cohen's d coefficient was used to examine the magnitude of change at different time intervals. Results. Starting from 34 weeks till 40 weeks, 50 ultrasound measurements were available at each gestational age. The mean (standard deviation) of AFI values (in cms) were 34 W: 14.59 (1.79), 35 W: 14.25 (1.57), 36 W: 13.17 (1.56), 37 W: 12.48 (1.52), 38 W: 12.2 (1.7), and 39 W: 11.37 (1.71). The 5th percentile cut-off was 8.7 cm at 40 weeks. There was a gradual decline of AFI values as the gestational age approached term. Significant drop in AFI was noted at two-week intervals. AFI curve generated from the study varied significantly when compared with already published data, both from India and abroad. Conclusion. Normative range for AFI values for late third trimester was established. Appreciable changes occurred in AFI values as gestation advanced by two weeks. Hence, it is recommended to follow up low risk antenatal women every two weeks after 34 weeks of pregnancy. The percentile curves of AFI obtained from the present study may be used to detect abnormalities of amniotic fluid for our population.

How safely can post-term pregnancies with uncertain gestational age be followed up using amniotic fluid index measurements?

Objective. To review whether 2 weeks’ follow-up is safe for women at 42 weeks with an uncertain gestational age (GA) and amniotic fluid index (AFI) of ≥10 cm, as well as reassuring cardiotocography (CTG). Methods. A retrospective descriptive study of women with an uncertain GA of 42 weeks was done at Tygerberg Hospital. The women had weekly CTG and AFI determinations. Induction of labour followed non-reassuring CTG or an AFI of <5. Results. A total of 135 women were studied. The time interval between first evaluation at uncertain 42 weeks and delivery ranged between 0 and 46 days (median 10 days). Of the women, 104 had normal vaginal deliveries and 31 (23.0%) caesarean sections. Eleven women (8.1%) with an AFI ≥10 had CS for fetal distress within 2 weeks of the visit at 42 weeks. No neonatal morbidity or mortality was noted. Conclusion. Weekly monitoring with CTG and AFI at 42 weeks with unsure GA is safe. A follow-up visit after 2 weeks cannot be recommended, as 8% of women required CS within less than 2 weeks because of fetal distress.

Obesity and pregnancy: a transversal study from a low-risk maternity.

BackgroundObesity is a public health problem and is increasing in all populations, including pregnant women. It influences maternal and neonatal outcomes; however, data are scarce in developing countries. We aimed to compare perinatal results between obese and non-obese pregnant women in a low-risk maternity.MethodsTransversal study of 1,779 40-week-pregnancies from 2005 to 2009 that completed a standard questionnaire with sociodemographic, obstetrical and neonatal variables and performed an ultrasound with amniotic fluid index (AFI) measurement and foetal vitality (FBP, non-stress test). They were analysed about their association with obesity on pregnancy.ResultsWhen compared with non-obese women, the group of obese patients had higher systolic (118.1 vs 109.2 mmHg; p < 0.01) and diastolic (76.6 vs 70.4 mmHg; p < 0.01) pressure levels, AFI (12.52 vs. 9.61 cm; p = 0.02), presence of meconium on labour (20.52 vs. 14.67%; p = 0.02), birthweight (3602 vs. 3437 g; p < 0.01) and caesarean section (39.74 vs. 29.98%, p < 0.01).ConclusionsLabour induction before 40 weeks in the antenatal period associated with foetal weight estimation should be considered as a recommendation for decreasing high percentages of caesarean delivery found in obese women.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2393-14-249) contains supplementary material, which is available to authorized users.

Does the level of amniotic fluid have an effect on the accuracy of sonographic estimated fetal weight at term?

Objective: Controversy exists concerning the impact of amniotic fluid index (AFI) on the accuracy of sonographic estimation of fetal weight (EFW). Thus, we aimed to evaluate whether differences in AFI has an influence on the accuracy of sonographic EFW.Methods: All term, singleton pregnancies which underwent a sonographic EFW and measurement of AFI within a week from delivery were included. Cases were stratified into three categories according to AFI: (1) Normal AFI (51–249 mm), (2) Oligohydramnios (AFI ≤ 50 mm) and (3) Polyhydramnios (AFI ≥ 250 mm). Inaccurate EFW was defined if there was more than 15% difference between sonographic EFW and actual birthweight.Results: Overall, 1746 pregnancies were identified (1096 with normal AFI, 455 with oligohydramnios and 195 with polyhydramnios). Mean AFI was 115.8 ± 60 mm, 28.1 ± 13 mm and 293 ± 35 mm, p < 0.001, and mean sonographic EFW was 3182.5 ± 573 g, 3118.8 ± 517 g and 3713.2 ± 461 g, p < 0.001, respectively. Demographic data and gestational age at delivery were similar. Mean birthweight was 3221.7 ± 535 g, 3132.5 ± 505 g and 3654.1 ± 480 g, p < 0.001, respectively. The rate of inaccurate EFW was similar between the groups (8.4%, 8.7% and 9.7%, p = 0.19, respectively). On multivariate analysis, AFI was not associated with EFW inaccuracy (OR 1.01, 95% C.I 0.67–1.54, p = 0.93).Conclusion: AFI has limited impact on the percentage of errors in sonographic fetal weight estimation a week prior delivery.

Reference range for amniotic fluid index measurements in a Brazilian population

The aim of this study was to determine the reference range for amniotic fluid index (AFI) measurements in a large sample of the Brazilian population. This was a retrospective cross-sectional study on 3837 normal singleton pregnancies between 18+0 and 38+6 weeks of pregnancy. The AFI was measured from the largest vertical pockets of amniotic fluid in the four quadrants of the uterine cavity. To assess the correlation between AFI and gestational age (GA), polynomial equations were calculated, with adjustments using the determination coefficient (R2). The mean maternal age and gestational age were 27.01±6.57 years and 30.43±5.29 weeks, respectively. The mean AFI ranged from 12.2±2.6 cm at 18 weeks to 11.6±6.0 cm at 38 weeks of pregnancy. The correlation between AFI and GA was best represented by a linear equation: AFI=17.78-0.153*GA (R2=0.027). We established the reference range for the AFI in a large sample of the Brazilian population. This reference range can be used to monitor deviations in the volume of amniotic fluid in fetuses at high risk for intrauterine growth disturbances.

Role of indomethacin in polyhydramnios

Objective: To observe the role of indomethacin in polyhydramnios. Method: This was a prospective, longitudinal and analytical study conducted in Kathmandu University Hospital, Dhulikhel from 1st July 2011 to 1st of December 2012. There were 32 patients included in the study. Indomethacin was administered orally at the dose of 25 mg three times a day for 1 week. The patients were admitted for observation of clinical symptoms, fundal height, fetal status and amniotic fluid index measurement. After the delivery, baby was investigated for any abnormality of fetal circulation. Results: There were total of 2700 deliveries in 1 year. Among them 46 cases were of polyhydramnios. The frequency was 1.7%. Among the 46 cases, 32 (69.6%) were idiopathic who were included whereas 8 (17.4%) were of diabetes mellitus, 4 (8.7%) were Rh isoimmunisation, and 2 (4.3%) were fetal anomalies. The mean age group was 24.5+/-4.2 years. There were total 10 (31.3%) patients presented at 29 weeks of gestation whereas only 5 (15.7%) patients at 32 weeks of gestation. Regarding the gravid index, 17 (53.1%) patients were primigravida. There was statistically significant reduction in amniotic fluid volume following 1 week administration of indomethacin. Conclusion: Though there are many modes of treatment for polyhydramnios, the 1 week therapy with indomethacin is equally beneficial. DOI: http://dx.doi.org/10.4038/sljog.v35i2.6167 Sri Lanka Journal of Obstetrics and Gynaecology 2013; 35: 50-52

Longitudinal assessment of amniotic fluid volume in monoamniotic twin gestations

The aim of this study is to describe normal amniotic fluid volume through gestation in a cohort of normal monoamniotic (MA) twins. Our ultrasound database was queried for MA twin gestations from 2004 to 2011. Monochorionic twin pregnancies mimicking MA gestations, such as twin-twin transfusion syndrome, were excluded. Complicated MA gestations and higher-order multifetal gestations involving an MA pair were excluded. Thirty subjects were followed with serial amniotic fluid index (AFI) measurements from 15 to 32 weeks gestation. Using each AFI measurement as a unique data point, a quadratic regression model and a multi-level growth model were developed against gestational age (GA), providing a predicted AFI at each completed week, with a 95% confidence interval. The quadratic regression least squares and multi-level growth models yielded the same curve comparing the AFI to the GA. Figure 1 depicts the model with the 95% confidence interval for normal amniotic fluid volume by GA for normal MA twins. Table 2 shows the 5th, 50th, and 95th percentiles for AFI by week from 15 to 32 weeks. We have generated normative data for amniotic fluid volume across gestation in uncomplicated MA twins. This can be used as a reference when managing MA pregnancies.