The amniotic fluid index in normal human pregnancy

doi:10.1016/0002-9378(90)90009-V

American Journal of Obstetrics and Gynecology

Volume 162, Issue 5, May 1990, Pages 1168-1173

https://doi.org/10.1016/0002-9378(90)90009-V Get rights and content

Summary

The four-quadrant sum of amniotic fluid pockets (amniotic fluid index) was studied prospectively in 791normal pregnancies. Interobserver and intracbserver variation was 3.1% and 6.7%, respectively. Logarithmic transformations were used to establish the mean and 90% confidence intervals for the amniotic fluid index at each week of gestation. In term pregnancies, the boundaries of the amniotic fluid index were 115 mm (mean), 68 to 196 mm (5th to 95th percentiles). In postdates pregnancies >42 weeks, the values were 108 mm (mean), 67 to 174 mm (5th to 95th percentiles), p < 0.0001. However, the values for each week were statistically distinct, indicating the need to reference amniotic fluid index measurements to week-specific normative tables for accurate interpretation. This study provides normative data for the amniotic fluid index thoughout pregnancy

References (19)

ChamberlainPF et al.
Ultrasound evaluation of amniotic fluid volume. I. The relationship of marginal and decreased amniotic fluid volumes to perinatal outcome
Am J Obstet Gynecol
(1984)
ChamberlainPF et al.
Ultrasound evaluation of amniotic fluid volume. II. The relationship of increased amniotic fluid volume to perinatal outcome
Am J Obstet Gynecol
(1984)
QueenanJT et al.
Amniotic fluid volume in normal pregnancies
Am J Obstet Gynecol
(1972)
CharlesD et al.
Amniotic fluid volumes in the second half of pregnancy
Am J Obstet Gynecol
(1965)
BraceRA et al.
Characterization of normal gestational changes in amniotic fluid volume
Am J Obstet Gynecol
(1989)
BottomsSF et al.
Limitations of using maximum vertical pocket and other sonographic evaluation of amniotic fluid volume to predict fetal growth: technical or physiologic?
Am J Obstet Gynecol
(1986)
ManningFA et al.
Antepartum fetal evaluation: development of a fetal biophysical profile
Am J Obstet Gynecol
(1980)
HoddickWK et al.
Ultrasonographic determination of qualitative amniotic fluid volume in intrauterine growth retardation: reassessment of the 1-cm rule
Am J Obstet Gynecol
(1984)
BeischerNA et al.
Studies in prolonged pregnancy. III. Amniocentesis in prolonged pregnancy
Am J Obstet Gynecol
(1969)

There are more references available in the full text version of this article.

Cited by (504)

Amnioreduction vs expectant management in pregnancies with moderate to severe polyhydramnios
2023, American Journal of Obstetrics and Gynecology MFM
The rate of polyhydramnios is higher in pregnancies complicated by congenital anomalies. These pregnancies have higher rates of peripartum complications. Amnioreduction is offered to relieve maternal symptoms such as dyspnea, abdominal and respiratory discomfort, and other issues like satiety.
This study aimed to report the rates of amnioreduction and its associated complications in pregnancies with moderate to severe polyhydramnios secondary to fetal anomalies. We also sought to determine if amnioreduction provided additional benefits, including prolongation of pregnancy and a decrease in the rates of peripartum morbidities associated with moderate to severe polyhydramnios.
This was a retrospective review of anomalous singleton pregnancies with moderate to severe polyhydramnios that were evaluated and delivered at a single center between 2013 and 2021. Peripartum outcomes were compared between pregnancies that underwent amnioreduction and those that were expectantly managed. Mann-Whitney U tests were used to compare continuous variables and Fisher's exact tests were used for categorical variables. A multiple regression model was created to understand the effects of amnioreduction on gestational age at delivery.
A total of 218 singleton pregnancies met the inclusion criteria of moderate to severe polyhydramnios in the study period. Of those, 110 patients (50.5%) underwent amnioreduction and 108 patients (49.5%) opted for expectant management. A total of 147 procedures were performed at a median gestational age of 32.5 weeks and a median of 1900 mL of amniotic fluid was removed per procedure. Complications occurred in 10.9% (n=16) of procedures, including preterm delivery within 48 hours in 5.4% cases (n=8). The median amniotic fluid index was higher in the amnioreduction group than in the expectant group (38.9 cm vs 35.5 cm; P<.0001). Patients who underwent amnioreduction had an earlier median gestational age at delivery (36.3 weeks vs 37.0 weeks; P=.048), however, the rates of spontaneous preterm delivery were similar. A higher percentage of women in the amnioreduction group had vaginal delivery (49.4% vs 30.5%; P=.01) and lower rates of uterine atony (2.4% vs 13.7%; P=.006). In the multiple linear regression analysis, the gestational age at delivery positively correlated with gestational age at amnioreduction after controlling for amniotic fluid volume (P<.0001; 95% confidence interval, 0.34–0.71). In addition, the patients in the amnioreduction group were twice as likely to have a vaginal delivery (P=.02).
Amnioreduction in the setting of moderate-severe polyhydramnios has a reasonably low rate of complications but does not provide any benefits in terms of prolonging the pregnancy. The procedure may increase the likelihood of vaginal delivery and lower the rates of uterine atony.
Tubular and glomerular biomarkers of renal tissue function in the urine of fetuses with posterior urethral valves
2022, Journal of Pediatric Urology
Posterior urethral valve (PUV) is a congenital malformation characterized by a membranous structure located in the prostatic portion of the male posterior urethra that obstructs the urinary flow. Efforts have been made to determine the degree of impairment of fetal kidney function in this condition.
This study aimed to measure the levels of urinary biomarkers of glomerular and tubular functions in fetuses with PUV and to compare with the levels of the same molecules in healthy male premature newborns.
Urine samples from 43 fetuses with PUVs were collected and compared with urine samples from 40 healthy male newborns of the same gestational age (controls). Tubular and glomerular biomarkers levels were measured in urine samples by MILLIPLEX® assay kits. Levels of the molecules were related to creatinine (Cr) measurements at same urine samples and expressed as pg/mg Cr. Results were analysed with Graphpad Prism version 7.0 and SPSS version 20.0.
Fetuses with PUV showed a significant reduction in urine levels of Epidermal Growth Factor (EGF), Calbindin, Osteoactivin, Molecule Renal Injury 1 (KIM-1 and Factor of trefoil 3 (TFF-3) when compared to controls. On the other hand, urine levels of cystatin C and renin were higher in PUV fetuses. The levels of molecules also differed according to urine osmolality and grade of hydronephrosis.
Some urinary excreted molecules may indicate kidney damage in several segments along the nephron, while others may exert important functions. Mechanical and immunological mechanisms related to PUV might significantly modulate the synthesis of cytokines related to glomerular and tubular physiology, leading to alterations in urinary concentrations of those molecules. These biomarkers can be used as future diagnostic and prognostic markers in clinical practice.
Early kidney structural and functional impairment influenced the synthesis of glomerular and tubular molecules related to kidney physiological processes in fetuses with PUV.
Predicting Factors of Protracted Intestinal Failure in Children with Gastroschisis
2022, Journal of Pediatrics
To identify prenatal and neonatal predictors of short bowel syndrome-related intestinal failure (SBS-IF) in gastroschisis.
This retrospective study included all patients with gastroschisis born between 2000 and 2017 who were enrolled in our home parenteral nutrition program, and all patients with gastroschisis born in our institution who survived 2 weeks, during the same time period. Prenatal ultrasound features, neonatal status, anatomic features, oral feeding, and parenteral nutrition dependency were analyzed.
Among 180 patients, 35 required long-term parenteral nutrition (SBS-IF group) and 145 acquired full oral feeding within 6 months (oral feeding group). The mean follow-up was 7.9 years (IQR, 1.6-17.5 years) and 5.0 years (IQR, 0.1-18.2 years), respectively. Both bowel matting (OR, 14.23; 1.07-16.7; P = .039) and secondarily diagnosed atresia or stenosis (OR, 17.78; 3.13-100.98; P = .001) were independent postnatal predictors of SBS-IF. Eighteen children (51% of the SBS-IF group) were still dependent on artificial nutrition at the last follow-up. patients with SBS-IF who achieved full oral feeding had a median residual small-bowel length of 74 cm (IQR, 51-160 cm) vs 44 cm (IQR, 10-105 cm) for those still dependent on artificial nutrition (P = .02). An initial residual small bowel length of more than 50 cm was the best predictive cut-off for nutritional autonomy, with a sensitivity of 67% and a specificity of 100%.
Bowel matting, complex gastroschisis, and secondary intestinal obstruction were associated with SBS-IF in gastroschisis. For patients with SBS-IF, a small bowel length of more than 50 cm was predictive of secondary nutritional autonomy.
Prenatal diagnosis and outcome of fetal hyperechogenic kidneys in the era of antenatal next-generation sequencing
2022, Clinica Chimica Acta
Fetal hyperechogenic kidneys (HEK) are associated with a wide range of etiologies and prognoses. Prenatal counselling and management can be extremely challenging, especially for isolated HEK.
A total of 28 pregnancies were screened by ultrasonography with HEK from March 1, 2016 to December 31, 2020. Genetic testings for aneuploidy and copy number variations (CNVs) are routine during the investigation for etiologies of fetal HEK in our unit. Trio-whole exome sequencing (WES) was offered to the family when karyotyping and microarray were not diagnostic. A systematic review (SR) was conducted to use the authoritative literature retrieval databases describing genetic testings’ results in prenatal HEK cases.
In the 28 HEK fetuses, 2 (7.14%) cases were identified with chromosome abnormalities and 6 (21.43%) cases were detected with pathogenic CNVs. Through trio-WES analysis, pathogenic or likely pathogenic variations were detected in the following genes: PKD1, BBS2, BBS9, HNF1B, PKHD1 and ETFA in another 10 (35.71%) fetuses. And the remaining 10 (35.71%) cases were undiagnosed. The pooled data from all reviewed studies indicate that HNF1B gene heterozygous deletion or mutation are the most common genetic causes associated with HEK.
This is the first study to accurately describe the genotype ratio at different levels of genetic testing associated with fetal HEK. Our study has suggested that trio-WES could improve the detection rate and efficiency of identification genetic pathologies in fetuses with isolated HEK. The WES results provide new evidences to guide prenatal counseling and management.
Fetal bladder morphology as a predictor of outcome in fetal lower urinary tract obstruction
2024, Prenatal Diagnosis
ISUOG Practice Guidelines: performance of third-trimester obstetric ultrasound scan
2024, Ultrasound in Obstetrics and Gynecology

View all citing articles on Scopus

View full text

The amniotic fluid index in normal human pregnancy

Summary

Am J Obstet Gynecol

Am J Obstet Gynecol

Am J Obstet Gynecol

Am J Obstet Gynecol

Am J Obstet Gynecol

Am J Obstet Gynecol

Am J Obstet Gynecol

Am J Obstet Gynecol

Am J Obstet Gynecol