The prenatal diagnosis of congenital heart disease--a practical approach for the fetal sonographer

With the widespread use of diagnostic ultrasound to evaluate the human fetus, it is now possible to diagnose a number of anomalies of varying organ systems. Although most anomalies of the central nervous, gastrointestinal, genitourinary, and skeletal systems are recognizable at birth, serious ones involving the cardiovascular system are often silent until the neonate demonstrates signs of cardiovascular compromise. Because an ever increasing number of fetuses are routinely scanned during pregnancy, it becomes imperative to incorporate a simple, logical approach to screen for cardiovascular disease during each fetal examination. The approach outlined in this paper would suggest that one method is the routine examination of the four-chamber view. Although there are a number of fetal and maternal risk factors which predispose to congenital heart disease, we have diagnosed a number of anomalies simply on the basis of the "screening" four-chamber examination in the "low-risk" fetus. For this reason, an attempt to examine the four-chamber view of the fetal heart should be done during each routine fetal examination. If an abnormality is noted, then a Level II, or consultative echocardiographic examination should be carried out. If a fetus at risk for congenital heart disease is being examined, a complete examination of the cardiovascular system (Levels I and II) should be performed. If the above approaches are integrated into obstetrical scanning, in the not too distant future it will be commonplace to diagnose cardiovascular anomalies prior to birth and thus provide the best care during the transition from the intrauterine to the extrauterine environment for the potentially cardiovascularly compromised neonate. The experience gained in our laboratory during the past 5 years strongly suggests that what is "today's research will become tomorrow's clinical tool."     

Adult valvular heart disease: a practical approach

The diagnosis and management of valvular heart disease is an important element of primary care practice. This article reviews the essential elements of four common valvular disorders, including signs and symptoms. The disorders reviewed are aortic stenosis, aortic regurgitation, mitral stenosis, and mitral regurgitation. The article places an emphasis on practical aspects of care.     

The fetal presacral pseudo-mass: a normal sonographic variant

We examined 416 consecutive third trimester intrauterine gestations over a 4-month period and discovered 26 hypoechoic masses in the fetal presacral space (6.3% incidence). These masses varied in diameter from 15 to 30 mm (mean, 21.5 mm). All neonates were normal on follow-up examination, without evidence of any masses or neurologic deficits. The fetal rectosigmoid colon frequently is identified in the third trimester and may reach 2 to 3 cm at term. Because the prevalence of meconium-filled rectum (6.3%) exceeds that of a presacral teratoma (0.0025%), this normal anatomic variant should be considered the most common cause of a third trimester presacral "mass."     

A sonographic study of fetal cystic hygromas

Fetal cystic hygromas are fluid filled sacs of lymphatic origin occurring in the posterolateral neck. Based on an experience with 15 of these hygromas diagnosed antenatally, the various sonographic appearances are illustrated and differential diagnostic features are discussed. A midline septum or hydrops may serve as diagnostic clues. The sonographic and anatomic features of a hygroma are correlated using a gelatin embedding technique.     

The sonographic approach to the detection of fetal cardiac anomalies in early pregnancy.

BACKGROUND: Transvaginal sonography enables imaging of the fetal heart in various planes and directions in early pregnancy. This study summarizes our experience in early detection of fetal cardiac anomalies. METHODS: Transvaginal sonographic examination was performed in 36 323 consecutive fetuses in both high- and low-risk pregnancies. More than 99% of cases were evaluated at 14-16 weeks' gestation. Examination of the cardiovascular system did not rely on still images of the classic views but instead was performed in a dynamic mode visualizing the heart and great vessels from different directions and in various scanning planes. RESULTS: Cardiac anomalies were detected in 173 fetuses, giving an overall incidence of 1 in 210 pregnancies. In 44% of these, the cardiac anomaly was isolated. An abnormal karyotype was detected in 27 of the 72 cases that underwent chromosomal analysis. An abnormal nuchal translucency finding was observed in 59 fetuses. The sonographic diagnosis was confirmed after delivery or at postmortem in 90 cases. Ten fetuses had a cardiac anomaly which differed from the anomaly suggested by sonography. In the remaining cases, a postmortem examination was not possible because termination of pregnancy was performed by dilatation and curettage. In four cases we did not detect the cardiac anomaly in early pregnancy. Two of them were detected at rescanning in mid-pregnancy. CONCLUSION: Early detection of fetal cardiac anomalies is now possible. Most anomalies occur in low-risk pregnancies. We suggest performing a detailed early multidirectional dynamic continuous sweep ultrasound examination of the fetal cardiovascular system in all pregnancies.     

The fetal thyroid: normal and abnormal sonographic measurements.

The thyroid of 31 fetuses at low risk for perinatal thyroid disease were evaluated sonographically. The transverse width and circumference of the fetal thyroid was measured prospectively to provide normative values for each gestational age. In addition, the thyroid of 23 fetuses at risk for thyroid disease were examined sonographically and compared to the control group. At birth, 18 of the neonates had no evidence of thyroid dysfunction, whereas 5 newborns had goiters and abnormal thyroid function. The fetal thyroid measurements for these 5 neonates were above the upper limit of the 95% confidence interval compared to the control group. The other 18 fetuses in the group at risk for thyroid disease but without evidence of thyroid dysfunction at birth had fetal thyroid measurement within the normal range.     

Anomalies of the fetal aortic arch: a novel sonographic approach to in-utero diagnosis.

OBJECTIVE: To describe a novel, sonographic approach for in-utero evaluation of normal and abnormal aortic arch. METHODS: Aortic arch was evaluated by imaging of the axial view of the upper fetal mediastinum. The normal left aortic arch was defined by the V-shaped appearance of the junction between the ductus arteriosus and aortic arch, with the trachea situated posteriorly. Right and double aortic arches were diagnosed when the great vessels appeared U-shaped, with intermediate location of the trachea. RESULTS: Between 1997 and 1999, 18 347 women were scanned in three prenatal centers, and pathological findings were prospectively recorded. In a retrospective analysis of the records, we identified 19 fetuses (0.1%) with atypical, U-shaped appearance, and no other structural abnormalities present. With the exception of one fetus with a ventricular septal defect, no congenital cardiac defects were present. Right aortic arch was found in 18 cases, while color Doppler made it possible to diagnose one case with double aortic arch, and one fetus was demonstrated as having Kommerell's diverticulum. In all 18 cases, a left descending aorta and left ductus arteriosus were present, the latter coursing to the left of the trachea, forming a loose partial vascular ring. All were asymptomatic at birth and early infancy. The fetus with double aortic arch that had a true vascular ring underwent early infantile correction. CONCLUSIONS: It is possible to diagnose right and double fetal aortic arch using prenatal ultrasound. The use of color Doppler facilitated in-utero evaluation of possible complications, such as true vascular ring.     

胎儿肾钙质沉淀症1例的声像表现

病例 孕妇，32岁，孕33周 6天，孕3产1，身体健康，无家族病史及不良嗜好，孕期服用过补钙剂，本次妊娠行孕期常规超声检查，超声显示：宫内为单胎妊娠，活胎，胎头位于下腹部，头颅光环完整，     

The changing sonographic appearance of fetal kidneys during pregnancy

One hundred consecutive women between 11 and 40 weeks of gestation were studied to evaluate the changing appearances of the fetal kidneys. In the first trimester, the kidney was never positively identified. Between 15 and 26 weeks it was seen but was difficult to distinguish from surrounding tissue. In the early third trimester, either an echogenic border or increased echogenicity of the renal sinus was observed; in the late third trimester this increased echogenicity was observed in both areas. It is thought that the echogenicity is the result of fat deposition in the pararenal space and in the renal sinus.     

The development of the fetal vermis: an in-utero sonographic evaluation.

OBJECTIVE: To establish a nomogram for fetal vermis measurements during gestation. METHODS: A prospective cross-sectional study of normal singleton pregnancies. Measurements of the fetal vermis width (in the axial plane) and height (in the sagittal plane) were performed by high-resolution transabdominal ultrasonography between 18 and 38 weeks of gestation in 256 fetuses. RESULTS: Adequate vermis measurements were obtained in 256 fetuses. Vermian width and height as a function of gestational age and biparietal diameter were expressed by regression equations and the correlation coefficients were found to be highly statistically significant (P < 0.0001). The normal mean (+/- SD) for each gestational week was defined. CONCLUSIONS: The present data offer the normal range of the vermian measurements throughout gestation. These values may allow intrauterine assessment of the development of the cerebellar vermis, as well as the posterior fossa.     

The development of the fetal sternum: a cross-sectional sonographic study.

OBJECTIVE: To assess the relationship between gestational age and sonographic appearance of the various sternal components and establish growth during human gestation. DESIGN: A prospective cross-sectional study. METHODS: The study was performed on 252 consecutive normal singleton pregnancies from 19 weeks of gestation until term, using transabdominal high-resolution ultrasound techniques. The sternal length, as well as the number of ossification centers at each gestational age, were recorded. RESULTS: The first occasion at which a fetal human sternum could be visualized with two to three ossification centers was at 19 weeks' gestational age. The fifth ossification center was first visualized at 29 weeks' gestation. The mean +/- SE of sternal length varied from 15 +/- 0.98 mm (95% confidence interval (CI) 12.79-17.21) at 19-20 weeks, to 36.50 +/- 0.29 mm (95% CI 35.58-37.42) at 37-38 weeks' gestation. Sternal length as a function of gestational age was expressed by the regression equation: sternal length (mm) = -11.06 + 1.39 x gestational age (weeks). The correlation coefficient, r = 0.924 for sternal length, was found to be highly statistically significant (p < 0.0001). CONCLUSIONS: The presented data offer normative measurements of the fetal sternum which may be helpful in the prenatal diagnosis of congenital syndromes that include, among other manifestations, abnormalities of sternal development.     

The fetal mandible: a 2D and 3D sonographic approach to the diagnosis of retrognathia and micrognathia.

OBJECTIVE: To define parameters that enable the objective diagnosis of anomalies of the position and/or size of the fetal mandible in utero. DESIGN: Fetuses at 18-28 gestational weeks were examined by two- and three-dimensional ultrasound. The study included normal fetuses and fetuses with syndromes associated with known mandible pathology: Pierre Robin sequence or complex (n = 8); hemifacial microsomia (Treacher-Collins syndrome, n = 3); postaxial acrofacial dysostosis (n = 1). Fetuses with Down syndrome (n = 8) and cleft lip and palate without Pierre Robin sequence or complex (n = 18) were also studied. Retrognathia was assessed through the measurement of the inferior facial angle, defined on a mid-sagittal view, by the crossing of: 1) the line orthogonal to the vertical part of the forehead at the level of the synostosis of the nasal bones (reference line); 2) the line joining the tip of the mentum and the anterior border of the more protruding lip (profile line). Micrognathia was assessed through the calculation of the mandible width/maxilla width ratio on axial views obtained at the alveolar level. Mandible and maxilla widths were measured 10 mm posteriorly to the anterior osteous border. RESULTS: In normal fetuses, the inferior facial angle was constant over the time span studied. The mean (standard deviation) value of the inferior facial angle was 65.5 (8.13) degree. Consequently, an inferior facial angle value below 49.2 degree (mean - 2 standard deviations) defined retrognathism. All the fetuses with syndromes associated with mandible pathology had inferior facial angle values below the cut-off value. Using 49.2 degree or the rounded-up value of 50 degree as a cut-off point, the inferior facial angle had a sensitivity of 1.0, a specificity of 0.989, a positive predictive value of 0.750 and a negative predictive value of 1.0 to predict retrognathia. In normal fetuses, the mandible width/maxilla width ratio was constant over the time interval studied. The mean (standard deviation) value was 1.017 (0.116). Consequently, a mandible width/maxilla width ratio < 0.785 defined micrognathism. Mandible width/maxilla width ratio values were below this cut-off point in eight and in the normal range in four fetuses with syndromes associated with mandible pathology. CONCLUSIONS: Retrognathia and micrognathia are conditions that can be separately assessed. The use of inferior facial angle and mandible width/maxilla width ratio should help sonographic recognition and characterization of fetal retrognathic and micrognathic mandibles in utero.     

A practical approach to hypercalcemia

Hypercalcemia is a disorder commonly encountered by primary care physicians. The diagnosis often is made incidentally in asymptomatic patients. Clinical manifestations affect the neuromuscular, gastrointestinal, renal, skeletal, and cardiovascular systems. The most common causes of hypercalcemia are primary hyperparathyroidism and malignancy. Some other important causes of hypercalcemia are medications and familial hypocalciuric hypercalcemia. An initial diagnostic work-up should include measurement of intact parathyroid hormone, and any medications that are likely to be causative should be discontinued. Parathyroid hormone is suppressed in malignancy-associated hypercalcemia and elevated in primary hyperparathyroidism. It is essential to exclude other causes before considering parathyroid surgery, and patients should be referred for parathyroidectomy only if they meet certain criteria. Many patients with primary hyperparathyroidism have a benign course and do not need surgery. Hypercalcemic crisis is a life-threatening emergency. Aggressive intravenous rehydration is the mainstay of management in severe hypercalcemia, and antiresorptive agents, such as calcitonin and bisphosphonates, frequently can alleviate the clinical manifestations of hypercalcemic disorders.     

A practical approach to intersex

The realm of intersex presents a challenge to the family as well the health care provider. As the physical aspects of diagnosis and management have become better understood, it has become apparent that there are psychological and social aspects that we have only begun to understand. A general overview of intersex issues that may confront the urologic practitioner, and the current concepts of diagnosis and management, are provided.     

A new two‐dimensional sonographic approach to the assessment of the fetal hard and soft palates

Facial clefts are among the most common congenital defects. Ultrasound (US) imaging of secondary fetal palate, especially the detection of isolated defects, remains challenging. Currently described two‐dimensional (2D) and three‐dimensional methods are technically demanding and impractical for application during routine fetal anatomy evaluation. As an adjunct method, magnetic resonance imaging can provide additional information but has its limitations. We present a novel 2D US approach using axial and sagittal planes to evaluate the fetal palate and demonstrate the main differences between an intact palate, isolated cleft palate, and a cleft lip with cleft palate.