Prenatal diagnosis of fetal polycystic kidney by ultrasound

Diagnosis of Fetal Abnormalities during the First Trimester

The quality of prenatal diagnosis of fetal abnormalities has advanced with improved resolution of ultrasound imaging and cytogenetic/molecular analysis. In this article, we briefly review the history of diagnosing fetal abnormalities and the current status of prenatal diagnosis during the first trimester (up to the first 14 weeks' gestation), focusing especially on fetal malformations and chromosomal abnormalities. As for detectable morphological abnormalities, roughly half of all major structural anomalies including those in the central nervous system, cardiovascular system and gastrointestinal system can be detected, if not definitely diagnosed. For screening of chromosomal abnormalities, especially for trisomy 21, ultrasound soft markers such as increased nuchal translucency, maternal serum markers and their combinations have been implemented. More recently, non-invasive prenatal testing, by analyzing cell-free DNA in maternal serum, is now available to detect chromosomal abnormalities with higher predictability. Although invasive chorionic villus sampling offers definite diagnosis for chromosomal abnormalities during the first trimester, non-invasive diagnostic techniques are patient-friendly and promising in the future perspectives on prenatal diagnosis for chromosomal abnormalities.

Renal cortical transit time in the evaluation of prenatally detected presumed pelvi ureteric junction like obstruction: A systematic review

Introduction

Differentiating nonobstructive from obstructive dilatation of the kidney is a clinical dilemma in prenatally detected hydronephrosis. Many radionuclide renogram parameters have been used to differentiate obstructed from non-obstructed units, including cortical transit time (CTT). We evaluate the role of CTT in identifying obstruction through a systematic review.

Methods

A literature search of the MEDLINE, MEDLINE In-Process, and MEDLINE Epub Ahead of Print, EMBASE, Google scholar, Pub Med, and Cochrane Library was done using key words - radionuclide renogram, CTT, parenchymal transit time, cortical transit, renography to identify articles on the subject. The identified articles were assessed for appropriateness and reviewed.

Results

The initial search yielded a total of 1583 articles, after adding the articles from references and applying the inclusion and exclusion criteria a total of 28 articles were selected. CTT showed good inter observer agreement in identifying obstruction. The use of CTT as a single parameter for determining the need for surgery and to identify those kidneys which will have functional improvement after surgery has been evaluated and has been found to be useful. CTT is best used in conjunction with ultrasonography to make clinical decisions.

Conclusion

The commonly used visual method of estimating the CTT, is a promising parameter for the evaluation of prenatally detected pelviureteric junction obstruction. Further well-designed multicenter prospective studies are needed to establish it as the most specific parameter to differentiate obstructive from nonobstructive dilatation of the pelvicalyceal system.

Diagnostic Value of Anteroposterior Diameter of Renal Pelvis for Predicting Postnatal Surgery: A Systematic Review and Meta-Analysis

PURPOSE

We assessed the diagnostic value of anteroposterior diameter of the fetal renal pelvis in predicting postnatal surgery.

MATERIALS AND METHODS

PubMed®, Embase® and Cochrane Library databases were searched for articles comparing patients who underwent surgery or conservative therapy with 15 mm anteroposterior diameter as a cutoff value. Data on sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic OR and area under the summary ROC curve were used to evaluate the diagnostic value of anteroposterior diameter of the fetal renal pelvis in predicting postnatal surgery.

RESULTS

Five studies involving a total of 1,159 patients met the inclusion criteria. The summary sensitivity and specificity were 0.81 (95% CI 0.60 to 0.92) and 0.78 (95% CI 0.68 to 0.86), respectively. Positive and negative likelihood ratios of anteroposterior diameter were 3.73 (95% CI 2.75 to 5.06) and 0.24 (95% CI 0.11 to 0.52), respectively. Diagnostic OR of anteroposterior diameter for predicting postnatal surgery was 13.33 (95% CI 6.61 to 26.89) and area under the summary ROC curve was 0.85 (95% CI 0.82 to 0.88). Subgroup analysis suggested postnatal anteroposterior diameter was associated with higher diagnostic OR compared to prenatal anteroposterior diameter for predicting postnatal surgery (ratio between prenatal and postnatal anteroposterior diameter 0.27, 95% CI 0.09 to 0.86, p = 0.026).

CONCLUSIONS

Using 15 mm anteroposterior diameter of the fetal renal pelvis as a cutoff showed moderate diagnostic value for predicting postnatal surgery.

Antenatal Diagnosis of Renal Tract Anomalies: Has it Increased the Sum of Human Happiness?

When used as a screening procedure, ultrasound examination of the fetal urinary tract seldom leads to beneficial interventions. There is also a cost in terms of parental anxiety and unnecessary investigation and treatment. A formal screening programme would therefore be unjustified. However, screening of women for obstetric purposes will continue to reveal fetal abnormalities, and a strategy for dealing with these is needed. Antenatal treatments remain experimental; for most of the common conditions postnatal treatment has no urgency; and, in cases of minor abnormality detected by ultrasound, the best course may be to do nothing.

Autonomy in Tension: Reproduction, Technology, and Justice

Respect for autonomy is a central value in reproductive ethics, but it can be a challenge to fulfill and is sometimes an outright puzzle to understand. If a woman requests the transfer of two, three, or four embryos during fertility treatment, is that request truly autonomous, and do clinicians disrespect her if they question that decision or refuse to carry it out? Add a commitment to justice to the mix, and the challenge can become more complex still. Is it unfair for insurance policies to exclude from coverage the costs of giving fertility to those who lack it or restoring fertility in those who have lost it? What does "just reproduction" look like in the face of multifarious understandings of both justice and autonomy and in light of increasingly complex and costly reproductive technologies? In today's dialogue about reproduction, medicine, and ethics in the United States, old ethical issues-such as whether women ought to be allowed to access pregnancy termination-are more contested than they have been in decades, while new technologies-like those used to edit the genes of human embryos-suggest that our species could face unprecedented questions about who should exist. As we considered the discussions accompanying these issues and contemplated a special report responding to them, we found ourselves consistently circling back to two ethical commitments: respect for autonomy and the pursuit of justice. As one of the nine essays in this collection asks, why should certain women receive help to establish a pregnancy while others are thrown in jail when they miscarry or their child is stillborn? Respect for autonomy is required where individuals have the ability to make fully informed and voluntary choices. Yet does respecting autonomy require acceding to all the choices of patients or consumers of medical care? We consider these and related questions in this special report from the Hastings Center Report.

Postnatal management of antenatally detected hydronephrosis

With the increasing use of ultrasonography, congenital anomalies are often picked in utero. Antenatally detected hydronephrosis is amongst the most commonly detected abnormality. The management of this condition has raised considerable debate amongst clinicians dealing with it. This article is written with an idea to provide comprehensive information regarding the postnatal management of antenatally detected hydronephrosis. A detailed review of the current literature on this topic is provided. Also, guidelines have been given to facilitate the management of this condition.

Prenatal ultrasound and urological anomalies

Prenatal ultrasound is an integral part of caring for pregnant women in the United States. Although surprisingly few data exist to support the clinical benefit of screening ultrasound during pregnancy, its use continues to rise. Urologic anomalies are among the most commonly identified, with overall detection sensitivity approaching 90%. Prenatal hydronephrosis is the most frequently identified finding and predicting postnatal pathology based on its presence can be difficult. As the degree of fetal hydronephrosis increases so does the risk of true urinary tract pathology. Diagnoses that require more urgent care include causes of lower urinary tract obstruction and bladder and cloacal exstrophy.

Predictive value of decreased renal pelvis anteroposterior diameter in prone position for prenatally detected hydronephrosis

PURPOSE

It is important to differentiate between those cases of prenatally detected hydronephrosis that are significant and those that are likely to resolve spontaneously. We evaluated the anteroposterior pelvic diameter of the renal pelvis postnatally in the supine and prone positions, and determined whether the difference between these 2 positions helps predict the outcome of prenatally detected hydronephrosis.

MATERIALS AND METHODS

From May 2009 to June 2011, 38 infants with prenatally detected unilateral ureteropelvic junction type hydronephrosis were evaluated. The anteroposterior pelvic diameter was noted in the supine and prone positions. Functional evaluation was done by radionuclide renogram. Those with a split function of less than 40% underwent pyeloplasty. All other patients were followed by serial ultrasound examination.

RESULTS

Six infants had an anteroposterior pelvic diameter larger than 40 mm with no change in diameter in the supine vs prone positions. Seven of 16 infants with an anteroposterior pelvic diameter between 30 and 40 mm, and 11 of 15 infants with an anteroposterior pelvic diameter between 15 and 30 mm had a smaller anteroposterior pelvic diameter in the prone position. These infants had normal renal function, improvement in hydronephrosis and did not need pyeloplasty. All the infants with no change in anteroposterior pelvic diameter in either position had poorer renal function, necessitating pyeloplasty.

CONCLUSIONS

Those cases of prenatally detected ureteropelvic junction type of hydronephrosis in which the anteroposterior pelvic diameter is smaller in the prone position than in the supine position showed improvement in hydronephrosis, while those with no change in anteroposterior pelvic diameter had worsening of hydronephrosis and needed surgical intervention.

Forty years of obstetric ultrasound 1957-1997: from A-scope to three dimensions

In this article, we record the history of obstetric ultrasound as it developed worldwide in the second half of the twentieth century. The technological advances during this period saw the evolution of equipment from the original adapted metal flaw detectors producing a simple A-scan to the modern, purpose built, real-time colour flow machines with three-dimensional capability (Fig. 1). Clinically, ultrasound began as a research tool, but the poor quality of the images led to the ridicule of many of the early investigators. However, because of their perseverance, ultrasound developed into an imaging modality providing immense diagnostic capabilities and facilitating with precision many invasive procedures, diagnostic and therapeutic, both of which have made significant contributions to patient care. In this history, we recall the people, the personalities, and the problems they encountered during the development of ultrasound and how these problems were resolved, so that ultrasound now is available for use in the care of pregnant women throughout the developed world.

Routine ultrasound screening of congenital anomalies. An overview of the European experience

Results from ultrasound in low-risk pregnant women are significant when routine screening is performed on a large population because the anomalies are rare. Professionals expect from routine ultrasound objective information that cannot usually be obtained by clinical procedures. Parents seek reassurance about the absence of fetal congenital anomalies and overall fetal health. Therefore, Europeans view routine ultrasound as a part of obstetrical care, capable of filling important gaps by delivering much key information for improving obstetrical practice. Fetal anomalies screening (FAS) requires higher education and qualifications than obstetrical ultrasound. The health insurance systems support ultrasound screening and allow its spread in most European countries; approximately 98% of pregnant women are examined by ultrasound and, frequently, two to three times (usually once per trimester). Detection rate of congenital anomalies is about 28% in geographical areas (private practice and hospitals), 60 to 80% in Ob/Gyn's ultrasound labs. Routine ultrasound screening policy has not proved to result in an immoderate use of ultrasound; on the contrary, chaotic use of routine ultrasound can lead to an unproductive and excessive number of scans. New trends in FAS, such as the early detection of fetal defects and chromosomal anomalies, bring more arguments for routine screening. Effectiveness should increase by enhancing education and training and the systematic referral for FAS to accredited laboratories.

Pediatric pyeloplasty: outcome analysis based on patient age and surgical technique

OBJECTIVES

To analyze our experience with open pyeloplasty, with specific emphasis on procedural outcome on the basis of patient age, surgical technique, complication rate, and complication management.

METHODS

All patients from 1974 to 1994 who underwent pyeloplasty at our institution were included in our review. Charts were analyzed for age at presentation, presenting signs and symptoms, type of surgical reconstruction, complications and treatment, and final outcome.

RESULTS

From 1974 to 1994, 234 pyeloplasties were performed in 227 patients (108 less than 1 year old, 119 more than 1 year old). The percentage of children less than 1 year old increased throughout: 24% for 1975 to 1980, 37% for 1981 to 1990, and 69% for 1991 to 1994. Presenting signs and symptoms varied according to the age of the child at pyeloplasty. For children less than 1 year old, these were prenatal ultrasound in 86 (79%), urinary tract infection (UTI) in 9 (8%), and abdominal mass in 5 (4.6%). For children more than 1 year old, these were pain in 57 (48%), UTI in 29 (24%), hematuria in 12 (10%), and prenatal ultrasound in 3 (2.5%). Reconstruction was a dismembered pyeloplasty in all cases. The majority of patients in both age groups underwent a nonintubated repair (less than 1 year old, 99 of 114; more than 1 year old, 102 of 120). Postoperative results were evaluated by ultrasound or intravenous urography, with improvement or stable results in 95% of children less than 1 year old and in 96% of children more than 1 year old. Complications included UTI in 18 patients (7.7%), recurrent obstruction in 5 (2.1%), and persistent leak in 4 (1.7%). The complication rate was not related to age.

CONCLUSIONS

The nonintubated, dismembered pyeloplasty is an excellent technique for all age groups and has a low complication rate.

Urinary tract anomalies detected by prenatal ultrasound examination at Mayo Clinic Rochester

OBJECTIVE

To determine the frequency of fetal urinary tract anomalies and to characterize the types of such abnormalities detected on ultrasonography and the outcome of affected patients during a 15-year period at our institution.

DESIGN

We retrospectively reviewed the findings on maternal prenatal ultrasound examinations and the postnatal medical records of 56 children with urinary tract abnormalities detected by prenatal ultrasound examination at Mayo Clinic Rochester from November 1979 to June 1994.

RESULTS

Of the 56 children, 18 (32%) had severe urinary tract anomalies in conjunction with oligohydramnios, pulmonary hypoplasia, and perinatal death (Potter's syndrome). The other 38 infants had various urinary tract abnormalities--most commonly, isolated hydronephrosis and multicystic dysplasia of the kidney. Six of the 38 children had more than one renal abnormality detected prenatally. Reflux was noted in association with prenatally detected urinary tract abnormalities in 4 of 32 newborns (12%) who underwent voiding cystourethrography. In fetuses with normal amniotic fluid volume, the perinatal outcome was good. Children with lower urinary tract obstruction had evidence of more severe renal dysfunction than did those with involvement at more proximal levels. The presence or absence of urinary tract obstruction postnatally could not be determined reliably on the basis of prenatal ultrasound appearance.

CONCLUSION

In this study, more than half of all prenatally detected urinary tract abnormalities were isolated hydronephrosis or multicystic dysplasia of the kidney. Postnatal renal function could not be reliably predicted on the basis of prenatal ultrasound findings.

Management of prenatally detected fetal hydronephrosis

The increased frequency of prenatal ultrasonography has resulted in an increase in the detection of fetal genitourinary abnormalities, many of which are of minimal clinical significance. Severe fetal urinary tract obstruction with associated oligohydramnios results in a recognizable constellation of physical findings, including renal dysplasia, pulmonary hypoplasia, and perinatal death. In selected cases, prenatal intervention to decompress urinary tract obstruction may reestablish amniotic fluid volume, prevent renal damage, and allow normal pulmonary development. After severe renal injury has occurred, intervention is unlikely to improve the prognosis of the affected fetus. Renal function may be analyzed prenatally by ultrasound examination and determination of chemical composition of fetal urine in order to identify fetuses in whom kidney development has not yet been irrevocably damaged and those likely to benefit from prenatal intervention. Postnatal renal evaluation with ultrasonography, voiding cystourethrography, and radionuclide imaging facilitates further characterization of the abnormality detected on prenatal ultrasound examination.

Prospective diagnosis of 1,006 consecutive cases of congenital heart disease in the fetus

OBJECTIVE

This report describes our experience with fetal congenital heart disease since 1980.

BACKGROUND

Knowledge and expertise in the diagnosis, management and natural history of fetal congenital heart disease is increasingly demanded by both obstetricians and parents. The analysis of a large series should help the pediatric cardiologist to provide this service.

METHODS

The notes of 1,006 patients, where a prospective diagnosis of fetal congenital heart disease was made, were reviewed. The reason for referral, the diagnosis made, the accuracy of diagnosis, the fetal karyotype and the outcome of the pregnancy were noted. The cases were grouped into malformation categories, and the spectrum of disease seen was compared with that found in infants.

RESULTS

Most fetal cardiac anomalies are now suspected by the ultrasonographer during obstetric scanning. A different incidence of abnormalities is seen compared with that expected in infants. Chromosomal anomalies were more frequent in the fetus than in live births. The accuracy of diagnosis was good. The survival rate after diagnosis was poor because of frequent parental choice to interrupt pregnancy and the complexity of disease.

CONCLUSIONS

A large experience with fetal congenital heart disease allows the spectrum of disease to be described with accuracy and compared with that in infancy. Knowledge of the natural history of heart malformations when they present in the fetus allows accurate counseling to be offered to the parents. If the trend in parental decisions found in this series continues, a smaller number of infants and children with complex cardiac lesions will present in postnatal life.

Urological anomalies in the Northern Region Fetal Abnormality Survey

From 1 January 1985 to 31 December 1990, the Northern Region Fetal Abnormality Survey received 736 notifications of fetuses with suspected urological abnormalities; a prevalence of three per 1000 births. There was a male:female ratio of 2:1, the ratio was higher in obstructive than in intrinsic renal parenchymal lesions. Overall diagnostic sensitivity was 68.9% and positive predictive value 50.8%. Hydronephrosis was the most frequent antenatal diagnosis (421 cases, 57.2%): 233 (55.3%) of these were found to be normal postnatally. There were 52 other false positive diagnoses. Of 113 babies with confirmed hydronephrosis antenatal diagnosis was correct in 97, sensitivity 85.8%, specificity 48.1%; 1.8% of these had chromosome defects. In 33 cases of bilateral renal agenesis antenatal diagnosis was correct or potentially correct in 24, sensitivity 72.7%, specificity 98.9%. Only six of 26 babies with posterior urethral valves were suspected, sensitivity 23%, specificity 98.7%. Mortality rate in 91 babies with unsuspected abnormalities was 39.6%: overall mortality was 24.2%. Unsuspected abnormalities occurred more frequently when mothers were not scanned after the 16th week of pregnancy.

Fetal echocardiography in the diagnosis of congenital heart disease

Fetal echocardiography provides an opportunity to diagnose congenital heart disease as early as the midtrimester of pregnancy, allowing for proper planning of perinatal care and counselling of the parents. This paper reviews the accuracy and outcomes of fetal cardiac ultrasound studies at The Prince Charles Hospital over the past 4 years. A total of 43 fetuses, of gestational ages 16-39 weeks, were studied. The indications for these were: previous sibling with cardiac anomaly (16 cases); abnormal heart on obstetric ultrasound scan (USS) (13 cases); abnormalities found on obstetric USS with normal appearing heart (one case); fetal bradycardia (seven cases); fetal tachycardia (four cases); irregular fetal heart beat (two cases). At birth all fetuses assessed because of a previously affected sibling were normal. Of the 13 referred because of structural heart lesions suspected on obstetric USS, eight were abnormal, four were normal and one was terminated without autopsy. Important rhythm disturbances occurred in nine of the 11 referred because of abnormal heart rates. One false positive diagnosis of a possible coarctation was made, and in four cases an abnormality was noted on USS but the diagnosis was not completely correct. Nine of the 19 infants with abnormalities detected have died. Fetal echocardiography is an accurate and useful method of diagnosing congenital heart disease in utero. Although the mortality of affected fetuses is high, antenatal diagnosis allows planning of medical care and offers the greatest chance of a successful outcome.

Prenatal diagnosis of urinary tract malformation

Malformation of the urinary tract (UT) is among the most common of all congenital malformations. Prior to the common usage of prenatal ultrasound, these anomalies were undetected until pediatric complications prompted investigation. When diagnosed and treated in early infancy, children with urinary tract malformations have a much better prognosis than when diagnosis is delayed beyond 1-2 years. Since the first report of the prenatal diagnosis of polycystic kidney disease by Garrett et al. in 1970, most forms of congenital urinary tract malformation have been diagnosed antenatally with the use of sonography. A review of the normal and abnormal development of the urinary system, some genetic aspects of UT malformations, and an overview of the major UT anomalies and their prenatal diagnosis is presented.

The dilemma of intrauterine diagnosis of congenital renal disease

The value of improved intrauterine diagnostic capability is unquestioned; however, as with all new technologic advancements, the problems created by this new diagnostic tool need review. This article examines some of the more critical of these difficulties.

Incidental fetal hydronephrosis: clinical implication

Maternal ultrasonography performed after twenty weeks of gestation is able accurately to identify and diagnose fetal hydronephrosis. We believe this finding should serve to alert the obstetrician as well as the pediatrician to potential complications which may arise at the time of delivery or immediately thereafter. Urologic evaluation and definitive surgical repair may then be performed when indicated.

Ultrasound in the diagnosis and management of urinary tract disorders in the fetus

Ultrasonic echography allows display of the fetal kidneys and urinary bladder from the 16th week of pregnancy, and the possibility of detection of a number of major congenital abnormalities of the urinary tract from that time. In the second half of pregnancy ultrasound has the key role in monitoring the progress of previously diagnosed abnormalities, particularly those of an obstructive nature. Sonologists thereby have an increasing responsibility in the obstetric care of the patient not only in the narrow field of diagnosis but in the wider field of management. Examples of conservative and surgical management of obstructive lesions are given.

Ultrasound diagnosis and perinatal management of fetal genito-urinary abnormalities

Approximately 50% of fetal abdominal masses originate in the urinary system and those recognizable ultrasonically include renal dysplasia, renal agenesis and obstruction of the lower excretory channels. Fetal renal anomalies may be discovered co-incidentally during the course of sonographic evaluation of uterine size-dates discrepancy, because they are commonly associated with fetal growth retardation and/or oligohydramnios, or during a planned sonographic follow-up of pregnancies in patients who are at risk of recurrence of such anomalies. The sonographic demonstration of renal anomalies under these circumstances may allow for elective termination of pregnancy, may modify the obstetric management and/or facilitate pediatric and surgical care of the newborn. In the collaboration study at three ultrasonic centers there were 81 cases of genito-urinary tract anomalies detected antenatally in a five years period. Among the detected anomalies there were 30 hydronephrotic fetuses, 12 with multicystic disease, 15 with Potter's syndrome, 10 with polycystic kidney, 9 with Prune Belly syndrome, 4 with isolated renal cysts and 1 with an ovarian cyst. Perinatal management of the fetus with urinary tract abnormalities greatly depends on the accuracy of the diagnosis. It would be justifiable to suggest that an inexperienced observer should not make the final diagnosis. He could be of great help, if one kept a high index of suspicion in patients with a significant family history of oligohydramnios and of unexplained abnormal cystic structures in the fetal abdomen and seek the help of a special referral center where experience in related cases is concentrated. Once an accurate diagnosis is made, various alternatives are open to the obstetrician. This is primarily dependent upon the type and degree of the abnormality. Unilateral multicystic kidney and hydronephrosis due to obstruction above the level of the urethra appear to be compatible with extrauterine life and should be approached accordingly. If there is massive enlargement of the fetal abdomen, elective cesarean delivery should be considered to prevent the dystocia which may occur with vaginal delivery and to prevent further damage of these vital organs. If bilateral renal agenesis, bilateral multicystic kidneys, or bilateral infantile polycystic kidneys are demonstrated early in gestation, the obstetrician and parents may choose to terminate the pregnancy because these conditions are not compatible with extrauterine life.(ABSTRACT TRUNCATED AT 400 WORDS)

Cystic kidneys. Genetics, pathologic anatomy, clinical picture, and prenatal diagnosis

According to the classification of Osathanondh and Potter of cystic kidneys we give an overview of the different types of cystic changes taking genetic aspects into account. Usually pathoanatomic types do not represent genetic entities: All type I kidneys are transmitted in an autosomal recessive way with varying clinical symptoms; in rare cases they even present in adults. The relationship to "congenital hepatic fibrosis", "cystic liver", and to the "Caroli syndrome" is discussed. Type II kidneys are usually not genetic in origin; but they may occur as part of several syndromes. Rarely genetic factors might contribute to type II kidneys that may present as familial cases of Potter syndrome ("renal non-function syndrome"). Type IV kidneys, although different in their pathoanatomic picture can be regarded according to a common pathogenetic theory as part of the spectrum of malformations as in type II. Therefore the genetic interpretation of type II kidneys also applies to type IV lesions. Type III kidneys include autosomal dominant polycystic kidney disease. This type may already present in childhood; the first prenatal diagnosis by ultrasonography is described in detail. Furthermore type III changes are part of syndromes or non-hereditary malformation complexes, and often present only as mild manifestations. Diseases with isolated involvement of the medulla (juvenile nephronophthisis/medullary cystic disease) or cortex are described as part of the differential diagnosis, they are heterogeneous and genetically only partly understood. Syndromes with cystic kidneys are reviewed as well as the possibilities of prenatal diagnosis of cystic diseases. Reliable prenatal diagnosis is only possible in type II, and possible in some of the other types. The nosology is improved if genetic information is taken into account.

Prenatal diagnosis of Potter's syndrome by ultrasound

A variety of fetal anomalies can be diagnosed by ultrasonographic examinations during the antepartum period. This report describes the first Scandinavian case of Potter's syndrome detected prenatally. The syndrome must be suspected whenever the combination of intrauterine growth retardation and severe oligohydramnios is seen. It is then essential to scan for the presence of fetal kidneys to establish that bilateral agenesis is not occurring.

Fetal hydronephrosis: problems in diagnosis and management

Experience with the prenatal diagnosis and management of four cases of congenital renal abnormalities is presented. Neither prenatal intervention nor early delivery was indicated in any of these patients. The current enthusiasm for aggressive management of fetal renal abnormalities may underestimate difficulties in prenatal diagnosis and overestimate the potential benefits of early intervention.

Genetics, pathoanatomy and prenatal diagnosis of Potter I syndrome and other urogenital tract diseases

We report on 12 early prenatal diagnoses of "Potter syndrome" and other severe fetal kidney diseases by ultrasonic observations of persistent oligohydramnios and absence of kidney function; seven pregnancies were terminated. These cases are discussed together with others observed in a total of 23 families. Special attention is given to the difficulty of classifying the various kidney diseases pathoanatomically, and also of determining the recurrence risk in the affected families. For genetic counselling, the possibility of early prenatal diagnosis is a practical solution to this problem. Routine ultrasound supervision of pregnancies can already detect a first, sporadic case of the various kidney diseases.

Early diagnosis of severe congenital malformations by ultrasonography

The significance of ultrasound examinations in early stages of pregnancy is illustrated by the detection of four severe congenital malformations within the first trimester and one malformation syndrome within the first part of the second trimester of pregnancy. We report on the diagnosis of a fetal POTTER syndrome (13 weeks), an anencephalic fetus (13 weeks), MECKEL-GRUBER syndrome (16 weeks), fetal exomphalos (12 weeks) and finally "Siamese twins" (11 weeks). Characteristic ultrasonographic findings are presented and described in detail. The incidence of these severe fetal abnormalities vary between 1:1000 (anencephaly), 1:6000 (exomphalos), 3:10,000 (POTTER-Syndrome), 1:50,000 (MECKEL-GRUBER Syndrome) and 1:250,000 (conjoined twins) live births. The sonographical diagnosis of all these malformation syndromes could be established by thorough and repeated inspection of the fetal head and fetal body with longitudinal and transversal scans. It is concluded, that the high and still increasing reliability congenital structural anomalies renders routine systemic ultrasound screening an attractive possibility already at this "early" stage of pregnancy.

Prenatal diagnosis of fetal urinary tract abnormalities by ultrasound

The prenatal detection of renal enlargement and sonolucent "cystic" lesions in 4 fetal abdomens by ultrasound is described. These were later proved to be congenital urinary tract anomalies. Only one of the other 4,628 mothers who had ultrasound gave birth to a child with a congenital urinary tract anomaly that was missed, and 1 fetus was falsely diagnosed as having a congenital urinary tract anomaly based on the ultrasound. Obstruction in the developing urinary tract is associated with renal dysplasia and insufficiency. More experience and improved ultrasonography may enable an accurate diagnosis of urinary tract obstruction; and early relief of the obstruction may be a possible method of management to minimize the renal damage.

Qualitative real-time cross-sectional echocardiographic imaging of the human fetus during the second half of pregnancy

In this study, we used high-resolution echocardiographic systems to investigate how early in pregnancy normal fetal cardiac anatomy could be noninvasively evaluated. Over a 2-year period, 84 of 88 fetuses were successfully imaged (27 were studied serially). Postnatal images of 73 were obtained during the newborn period. Estimated fetal age varied at initial examination from 19-41 weeks (mean +/- 0.5 weeks [+/- SEM]) of pregnancy. Estimated fetal weight using an ultrasound algorithm varied from 500-3100 g (mean 1580 +/- 80 g [+/- SEM]). To evaluate fetal cardiac anatomy, we reproduced commonly used cross-sectional views of the heart. The four-chamber and the short-axis great artery views have been most successful for cardiac evaluation in the fetus. These views could be obtained in 96% and 95% of the patients, respectively. With these views, cardiac chamber and valve structures, as well as two great arteries, could be imaged in detail. The ascending and descending aorta, as well as the aortic arch and vessels to the arms and head, were visualized in 87% of examinations, and the inferior and superior venae cavae were visualized in 76%. In two of three RH fetuses, changes in cardiac chambers compatible with hydrops fetalis were demonstrated. We examined all fetuses after birth and verified clinically (or noninvasively) that no cardiac malformations were present. It appears, however, that the diagnosis of major congenital heart defects should be possible before birth.

Realtime sonographic diagnosis of fetal dysplastic kidney

A case of unilateral renal dysplasia was diagnosed in utero using realtime scanning. The diagnosis was confirmed neonatally and the affected kidney was surgically removed. Pathologic findings were consistent with the features of this malformation. The echographic characteristics of renal dysplasia and the differential diagnosis are described. The potential uses of ultrasonography in the diagnosis and follow-up of pregnancies associated with or at risk of renal malformations are discussed.

Diagnosis and assessment of fetal malformation and abnormalities by ultrasound

With remarkable improvements in antenatal, intrapartum and the newborn care, the proportion of perinatal problems attributable to congenital abnormalities has significantly increased. The number of deaths due to fetal malformations in some countries now approaches the number due to prematurity and it is justifiable to believe that abnormalities will soon be heading the league of causes of perinatal death. Even with the most advanced treatment teams and resources, many seriously malformed children cannot be habilitated to any reasonable degree. It is therefore obvious that the future of these types of disorders lies ultimately in their prevention. This has long been the hope of obstetricians and in certain abnormalities this can become a reality. With the advent of ultrasound, many structural anomalies cannot be evaluated by direct visualization of the placenta and fetal anatomy. The number of pregnancies monitored available and as public education about genetics increases. Diagnostic ultrasound has proved to be a powerful means of preventing the birth of babies with significant defects. If this has not been achieved in early pregnancy, the knowledge that the fetus is or may be abnormal at the end of pregnancy can still be valuable, since the management of patients before and during labour could be radically altered. Therefore, ultrasound examination should be preferred as the initial test because it is without risk and produces no side effects.

Ultrasonographic diagnosis of fetal hydronephrosis in utero

Ultrasonography offers a noninvasive method to visualize antenatal or neonatal anatomy which will lead to early detection and treatment of abnormalities. In these 2 cases, ultrasound allowed prompt diagnosis of hydronephrosis despite normal physical examination and laboratory values at birth.

Prenatal diagnosis of renal anomalies

Within the past 24 months, we have performed prenatal diagnostic studies in 4 pregnancies known to be at risk for well-described genetic syndrome involving renal abnormalities, ie, Meckel syndrome, Roberts syndrome, and bilateral renal agenesis. The diagnostic techniques utilized were ultrasonographic scanning (B-mode and grey scale), biochemical assays, and radiographic evaluation. The ultrasound finding common to the 3 affected cases was extreme oligohydramnios, which we considered indirect evidence that renal anomalies were present. The ultrasound scans of the fetuses affected with Meckel and Roberts syndrome demonstrated anechoic cystic spaces in the abdomen, representing the enlarged dysplastic cystic kidneys. An encephalocele was well demonstrated by B-mode scan in the fetus with Meckel syndrome. The absence of normal limbs in the Roberts syndrome was evident on serial grey scale scans of the fetus. Biochemical and radiographic studies provided results consistent with the suspected diagnoses. The importance of providing genetic counseling and prenatal diagnosis to families at risk is emphasized.

Prenatal detection of anencephaly

Fetal anomalies were suspected clinically in 3 patients, during the second trimester of pregnancy, due to advanced maternal age, hydramnios and abnormal vaginal bleeding respectively. Sonography revealed anencephaly in all of them, confirmed by roentgenograms and also by high amniotic fluid leveal alpha-fetoprotein in 1 of them. The antenatal diagnosis was confirmed in the 3 abortuses. Early screening of all pregnancies at risk for neural tube malformations is strongly recommended.

The diagnosis of fetal hydronephrosis, megaureter and urethral obstruction by ultrasonic echography

Two cases of fetal urethral obstruction, one with megaureter and obvious hydronephrosis, were diagnosed by two-dimensional ultrasonic echography. With good quality echograms it should be possible to make the diagnosis early in pregnancy.