Accuracy in estimating fetal urinary bladder volume using a modified ultrasound technique

Abstract

Objective: To evaluate the accuracy and assess the indications of fetal echocardiography to diagnose structural heart disease in our high risk population, by an obstetric team. Methodology: Over a 4-year period, a transabdominal echocardiography was performed in 912 high risk pregnancies for congenital heart disease at 18-38 weeks of gestation. In the last 140 cases, an early examination combining either the transvaginal or the transabdominal route at 13-16 weeks was also carried out. Follow up was obtained from neonatal examinations and autopsies. The main indications for referral were: pregestational diabetes mellitus, family risk, increased nuchal translucency, suspected cardiac anomaly at screening ultrasound, women at high risk of chromosomal abnormality reluctant to invasive test, suspected arrhythmia, single umbilical artery, exposure to teratogens, and pregnancies affected by a chromosomal abnormality. Results: There were 79 (8.6%) major congenital heart defects, and most of them were yielded in the group of screening by ultrasound. Seventy of them (88.6%) were diagnosed correctly as abnormal prenatally. Atrioventricular septal defects (21 cases) and hypoplastic left ventricle syndrome (12 cases) were the most prevalent heart anomalies in the fetus. Isolated septal defects and coarctation of the aorta were the most difficult lesions to detect, being the ones with false positive and negative diagnosis. Another four cases of non-significant (<3 mm, no surgery nor medical treatment required) ventricular septal defects were overlooked during gestation, but closed by the sixth month of life. Fifteen apparently normal cases were lost to follow up. Conclusion: Our obstetric team results, in accordance with others previously published, show a good effectiveness to diagnose congenital heart anomalies. Most major detectable cardiac anomalies occur in the group without previously-known risk. Fetal echocardiography is optimized by a team strategy of imaging by obstetricians/high risk obstetric scanners (O) and fetal pediatric cardiologists (FPC). We retrospectively examined 1037 studies (1995)(1996)(1997)(1998)(1999), and identified 249 cases of major congenital heart disease. The O diagnosis was compared to the FPC diagnosis and postnatal diagnosis. The rate of complete accurate diagnosis for O and FPC diagnosis were 59% (17% false positive, 41% negative), respectively. Major differences in diagnosis or detail were found in 79 patients after FPC was completed and in 35/79 (44%) this was judged to have potential significant impact on management and prognosis counseling. The complementary roles of O and FPC remain important. FPC can contribute with additional detail in some cases which may significantly impact on counselling and planning. F03Factors influencing the prenatal detection of structural congenital heart diseases S.-F. Wong, F.-Y. Chan, R. Cincotta, A. Lee-Tannock & C. Ward Background: Congenital heart disease is the commonest congenital anomaly, but the reported antenatal detection rate varies widely from ...

Measurement of fetal urine production by three‐dimensional ultrasonography in normal pregnancy

“…They calculated bladder volume by rotating the longitudinal fetal bladder shape around its long axis. Using this method they reported that the standard deviation was reduced to 3.5–8.8%, compared with 5.5–12.5% using the ellipsoid formula16. Although this method provided a more accurate estimation than the ellipsoid formula, as it is independent of longitudinal bladder shape, it is nevertheless based on the assumption that the bladder is a rotational body around its long axis.…”

Estimation of fetal urinary bladder volume using the sum‐of‐cylinders method vs. the ellipsoid formula

“…The study material comprised longitudinal fetal bladder images, which were used in a previous 2D ultrasound study7 in 1998–1999 conducted at the Department of Obstetrics and Gynaecology, North Elfsborg County Hospital, Trollhättan, Sweden. The gestational ages were between 24 and 40 weeks and 34 fetuses (all singletons) were included.…”

“…In the present study, the identical images from the aforementioned7 study were re‐evaluated at the same institution in 2000–2001. Using identical bladder images, SD ‘total error straight sequence ’ and SD ‘frozen error one image ’ were estimated.…”

“…The aim of this study was to evaluate the sum‐of‐cylinders method when calculating the fetal urinary bladder volume. Moreover, the volumes estimated by this method were compared with those found when the ellipsoid formula was used on identical bladder images in a previous study7.…”

Measurement of fetal urine production to differentiate causes of increased amniotic fluid volume

“…AF volume is determined by several factors4, and any disturbance in the regulatory mechanism can induce polyhydramnios. Fetal urine production can be measured by serial assessment of bladder volume with two‐dimensional5–18 and, as described more recently, three‐dimensional19–22 ultrasound. We undertook this study to evaluate whether measurement of the urine production rate (UPR) in fetuses with increased AF volume can be used to differentiate the causes of polyhydramnios.…”