Prenatal diagnosis of isolated hypospadias

Predictive value of ultrasound in prenatal diagnosis of hypospadias: hints for accurate diagnosis

OBJECTIVES

This study aims to assess the diagnostic accuracy of targeted ultrasound examination in prenatal diagnosis of hypospadias and to evaluate the predictive values of defined ultrasonographic findings of hypospadias.

METHODS

The cases diagnosed with hypospadias in our fetal medicine center were identified on an electronic database. The ultrasound reports, images and hospital records were reviewed retrospectively. The predictive value of prenatal ultrasound diagnosis and the predictive values of each sonographic finding were assessed according to the postnatal clinical examinations.

RESULTS

Thirty-nine cases were diagnosed with hypospadias on ultrasound during the 6 years. Nine fetuses with missing postnatal examination records were excluded. Twentytwo of the remaining fetuses had their prenatal diagnosis of hypospadias confirmed in postnatal examinations, indicating a 73.3 % positive predictive value. Normal external genitalia was detected in postnatal examinations of three fetuses. Five fetuses were diagnosed with other external genital abnormalities, including micropenis (n=2), clitoromegaly (n=2), and buried penis with bifid scrotum (n=1) in postnatal examinations. The positive predictive value of prenatal ultrasound for any external genital abnormality was 90 %.

CONCLUSIONS

Although the positive predictive value of ultrasound for genital anomalies is satisfying, it is slightly lower for the specific diagnosis of hypospadias. This reflects overlapping ultrasound findings of different external genitalia anomalies. Standardized, systematic evaluation of the internal and external genital organs, karyotyping and genetic sex determination are essential to achieve a precise prenatal diagnosis of hypospadias.

Imaging in fetal genital anomalies

Genital anomalies are a heterogeneous group of congenital pathologies that have become increasingly relevant since the Chicago Consensus of 2005. Their postnatal diagnosis has developed significantly in the last two decades, while prenatal diagnosis seems to be underdeveloped, with few protocols available, fragmented scientific literature, and low diagnostic rates. This review aims to examine the current status of this subspecialty from the perspective of prenatal imaging. Indications for the evaluation of fetal genitalia can be divided into medical and non-medical reasons. Medical reasons include sex-linked disorders, detection of other anomalies, relevant family history, or multiple pregnancy. Non-medical reasons include parental request for sex disclosure. Disclosure of fetal sex may be associated with ethical, legal, and medical issues. The main imaging technology used is 2D ultrasound, although there are other complementary techniques such as 3D, MRI, or Color Doppler. Regarding working methodology, several authors have drawn attention to the lack of standardized protocols and guidelines. Most guidelines tend to limit their recommendations to study indications and ethical issues. Technical proposals, measurements, or working methods have not yet been standardized. Fetal sex determination is usually divided into early and late gestation. Early gestation is based on the sagittal sign. Late gestation is based on direct visualization. There are several measurements to describe male and female genitalia, such as penile length, bilabial diameter, or scrotal diameter. Prenatal diagnosis of genital pathologies presents some particularities such as the wide spectrum of phenotypes, the high frequency of associated deformities, or the time of diagnosis. Some of the most frequent pathologies are ambiguous genitalia, fetal sex discordance, hypospadias, micropenis, clitoromegaly, ovarian cysts, hydro(metro)colpos, and cloacal anomalies. Higher-quality studies and direction from scientific societies through the implementation of clinical guidelines are needed.

Prenatal and postnatal imaging techniques in the evaluation of disorders of sex development

Imaging of the reproductive tract is challenging and requires a general knowledge of congenital variations in anatomy. The anatomy of the developing fetus, whether a male phenotype or female phenotype, is also a dynamic process with many changes occurring during gestation. Families may ask details about the genitalia during prenatal imaging and when variations in what is thought to be normal are present, further investigation is sometimes needed to make sense of what is seen. This overview will describe categories of disorders of sex development (DSD), whether chromosomal or structural or both, and the current state of imaging of these anomalies.

Prenatal imaging of genital defects: clinical spectrum and predictive factors for severe forms

OBJECTIVES

To report the clinical spectrum of genital defects diagnosed before birth, identify predictive factors for severe phenotypes at birth, and determine the rate of associated malformations.

PATIENTS AND METHODS

A retrospective study (2008-2017) of 4580 fetuses, identified prenatally with abnormalities evaluated by our Reference Center for Fetal Medicine, included cases with fetal sonographic findings of abnormal genitalia or uncertainty of fetal sex determination. Familial, prenatal and postnatal data were collected via a standardised questionnaire.

RESULTS

In all, 61 fetuses were included. The positive predictive value (PPV) of the prenatal diagnosis of genital defects was 90.1%. Most cases were 46,XY-undervirilized boys, 42 cases (68.8%), which included 29 with mid-penile or posterior hypospadias, nine with anterior hypospadias, and epispadias, micropenis, scrotal transposition, and buried penis (one each). In all, 46,XX-virilized girls were identified in seven cases (11.5%), which included four with congenital adrenal hyperplasia, two with isolated clitoromegaly, and one with ovotestis. Other defects included prune belly syndrome and persistent cloaca (six cases). Early detection during the second trimester (58.1% vs 18.8%, P = 0.03), intra-uterine growth restriction (IUGR) (45.2% vs 9.1%, P = 0.06), and curvature of the penis (38.7% vs 0%, P = 0.02), were more frequently related to severe defects in male newborns. Associated malformations (14 cases, 22.9%) and genetic defects (six) were frequent in undervirilized boys.

CONCLUSION

Prenatal imaging of genital defects leads to a wide range of phenotypes at birth. Its PPV is high and extra-urinary malformations are frequent. Early diagnosis during the second trimester, associated IUGR, and curvature of the genital tubercle, should raise suspicion of a severe phenotype and may justify delivery near a multidisciplinary disorders/differences of sex development team.

Ultrasound diagnosis of fetal hypospadias: Accuracy and outcomes

OBJECTIVES

The purpose of this study was to assess the positive predictive value of a prenatal ultrasound diagnosis of hypospadias when compared with postnatal diagnosis based on physical exam.

METHODS

We retrospectively identified all pregnant women between 2004 and 2014 who were either referred to our fetal care center carrying a fetus with an ultrasound diagnosis of possible hypospadias or who had a new diagnosis of hypospadias after imaging in our center.

RESULTS

A total of 32 cases of possible hypospadias were identified, with our fetal center ultrasound suggesting hypospadias in 25 of the 32 cases (78%). Of the 25 cases, 18 infants were confirmed to have hypospadias on postnatal physical exam (Table), reflecting a positive predictive value of 72%. Twenty-one of twenty-five cases with suggested hypospadias on ultrasound were found to have either hypospadias or another penile anomaly on postnatal physical exam, reflecting a positive predictive value for any genital anomaly of 84%. Infants with confirmed hypospadias often had several associated GU anomalies on postnatal clinical exam.

CONCLUSIONS

Our single center experience with the fetal ultrasound diagnosis of hypospadias demonstrates a high positive predictive value for a penile anomaly (21/25, 84%), and a moderately high positive predictive value for the specific diagnosis of hypospadias (18/25, 72%) when compared with the postnatal diagnosis.

X-linked congenital adrenal hypoplasia associated with hypospadias in an Egyptian baby: a case report

Introduction

X-linked congenital adrenal hypoplasia is a rare developmental disorder of the human adrenal cortex and is caused by deletion or mutation of the dosage-sensitive sex reversal adrenal hypoplasia congenita critical region of the X chromosome, gene 1 (DAX-1) gene. Most affected children present with failure to thrive, salt wasting and hypoglycemic convulsions in the first months of life. Hypospadias affects approximately one in 250 live male births. Mutations in the mastermind-like domain-containing 1 (MAMLD1) gene have been implicated as one of the causes of hypospadias in children. To the best of our knowledge, an association between congenital adrenal hypoplasia due to a DAX-1 mutation and hypospadias due to mutation of the MAMLD1 gene has not previously been reported in the literature.

Case presentation

A 35-day-old male Egyptian baby was referred to our institution for the evaluation of a two-week history of recurrent vomiting associated with electrolyte imbalance. On examination, our patient was found to have hypotension and dehydration. A genital examination showed distal penile hypospadias with chordee and normal testes. He had hyponatremia, hyperkalemia, hypoglycemia and metabolic acidosis. Endocrinological investigations revealed low levels of cortisol, 17-hydroxyprogesterone and aldosterone, with a high level of adrenocorticotrophic hormone. A provisional diagnosis of congenital adrenal hypoplasia associated with hypospadias was made. A molecular genetics study confirmed the diagnosis of X-linked congenital adrenal hypoplasia due to DAX-1 mutations and hypospadias due to MAMLD1 mutation. He was started on hydrocortisone and fludrocortisone treatment. After three weeks of treatment, his symptoms improved and his blood sugar, sodium, potassium and cortisol levels normalized.

Conclusions

We report the case of an Egyptian baby with an association of congenital adrenal hypoplasia due to DAX-1 mutation and hypospadias due to MAMLD1 mutation. Early diagnosis of this association and determining its optimal treatment are vital in helping to avoid its fatal course.

Acrania-anencephaly associated with hypospadias. Prenatal ultrasound and MRI diagnosis and molecular folate metabolism pathway analysis

Acrania may occur as a single isolated malformation or associated with extracranial defects. Hypospadias is one of the most common congenital abnormalities of the genitalia frequently missed on prenatal sonograms. Second trimester two- and three-dimensional ultrasound and MRI diagnosis with necropsy and folate metabolism pathway analysis. The mechanisms leading to closure of both neural and urethral tubes, are far from being demonstrated, and molecular studies of this very rare association are lacking although it might be based on a common genetic mechanism, leading to a disturbed development pathway at the molecular level.

Prenatal two- and three-dimensional imaging in two cases of severe penoscrotal hypospadias

We present the prenatal two- and three-dimensional (3D) ultrasound (US) findings in two cases of severe penoscrotal hypospadias. 3D sonography was used for better definition of ambiguous genitalia. The images were compared with postnatal clinical features. Despite hypospadias being the most common urogenital anomaly of male neonates, the diagnosis is often missed before birth. Performing prenatal ultrasound should include the study of genitals, not only determining the sex.

Abnormalities of the penis in utero--hypospadias on fetal MRI

OBJECTIVE

To demonstrate the visualization of penile abnormalities on fetal magnetic resonance imaging (MRI).

METHODS

This retrospective study included five fetuses (25+0 to 31+6 gestational weeks) with penile abnormalities, positively depicted on fetal MRI, using prenatal ultrasonography (US) as a standard of reference. On MRI, the penis, as well as the scrotum and testicles, were evaluated. All fetal organs were reviewed to define penile abnormalities as isolated or in association with other anomalies. Furthermore, US and MRI findings were compared.

RESULTS

Posterior hypospadias were demonstrated in all five fetuses, and abnormal testicular descent in two. Associated anomalies were present in all five fetuses on MRI, including abdominal/urogenital pathologies in four; brain pathologies in three; and craniofacial, cardiac, musculoskeletal, pathologies each in one fetus, and intrauterine growth retardation in one fetus. Compared to US, additional MRI findings were shown in four of five fetuses.

CONCLUSIONS

Our MRI results demonstrate the visualization of fetal penile abnormalities and associated pathologies, which may provide information for perinatal management. MRI may show additional findings compared to prenatal US in certain cases.

3D, Vocal and Tomographic Ultrasound Image in Prenatal Diagnosis of Hypospadias

We report a case of anterior hypospadias, diagnosed at 26th week in a 37 years-old primigravida with normal 46XY kariotype through amniocentesis carried out at 16th week.

Sonographic examination with 2D showed a short and curved penis. The use of three orthogonal planes, Tomographic Ultrasound Image (TUI) and VOCAL allowed an exact prenatal diagnostic, showing the “tulip” sign and defining localization, situation and extension of the urethral orifice.

Hypospadias mimicking female genitalia on early second trimester sonographic examination

Female fetal sex was assigned based on downward direction of the genital tubercle at 14 weeks' gestation. Subsequently, amniocentesis performed due to the finding of an echogenic focus in the left ventricle revealed a male karyotype. Sonographic examination at 22 weeks' gestation revealed a markedly curved penile shaft. Power Doppler at that time demonstrated a urine jet emanating from the penile base, verifying the diagnosis of penoscrotal hypospadias. We therefore suggest that female fetal sex assignment should be based on the demonstration of the 2 or 4 parallel lines representing the labial folds and not only upon the demonstration of the downward direction of the genital tubercle.

Prenatal Sonographic Features of Hypospadia: Two- and Three-Dimensional Findings

OBJECTIVE

To present our experience of applying three-dimensional ultrasonography in prenatal diagnosis of hypospadia.

CASE REPORT

A 28-year-old woman, gravida 1, para 0, visited our hospital at 17 weeks' gestation. No gross anomaly was found on the scan at 21 weeks' gestation. Fetal growth was appropriate for gestational age on two-dimensional (2D) ultrasonography at 27 weeks' gestation, but an abnormally curved and shortened fetal penis was found incidentally. Three-dimensional (3D) imaging in surface-rendered mode was used to reconstruct the fetal penis. Multiplanar and surface-rendered images were obtained in the midsagittal, axial, and coronal planes to precisely delineate the ventral curvature of the penis. At 39 weeks' gestation, a term newborn was delivered by vacuum extraction. On examination, the fetus was confirmed to have hypospadia. Karyotyping revealed 46,XY.

CONCLUSION

2D ultrasonography could only give indirect clues of hypospadia that was later more precisely delineated by 3D ultrasonography in surface-rendered mode.

Sonography of fetal micturition

OBJECTIVE

To describe the sonographic visualization of fetal micturition and its role in the diagnosis of posterior urethral valves and hypospadias.

METHODS

This was a prospective study of 25 male fetuses (21 with bilateral pyelectasis, one whose bladder was being studied because of ureterocele and three with hypospadias), and five female fetuses (with bilateral pyelectasis). A midline sagittal scan of the fetal pelvis, perineum and external genitalia was obtained and observed continuously during fetal micturition.

RESULTS

In 19 of the 21 male fetuses and the five female fetuses with bilateral pyelectasis micturition was normal, with visualization of urinary bladder contraction, slight fluid distention of the urethra and a urinary stream from the external urethral meatus. In three male fetuses, two with bilateral pyelectasis and the one with ureterocele, the posterior urethra was normal at rest and it ballooned out during micturition, diagnostic of posterior urethral valves. In the three male fetuses with hypospadias the ventral jet of the urinary stream was visualized.

CONCLUSION

Fetal micturition can be visualized on sonography. It may be of value in the diagnosis of posterior urethral valves and hypospadias.

Prenatal diagnosis of Wolf-Hirschhorn syndrome (4p-) in association with congenital hypospadias and foot deformity

BACKGROUND: Wolf-Hirschhorn syndrome is caused by distal deletion of the short arm of chromosome 4 (4p-). We report a case in which intrauterine growth restriction, hypospadias and foot deformity were detected by prenatal ultrasound examination at 29 weeks of gestation. CASE PRESENTATION: A 31-year-old gravida 2 partus 1 woman was referred at 29 weeks' gestation with suspicion of intrauterine growth restriction. Sonographic examination revealed deformity of the right lower limb and undescended testes with an irregular distal penis. A cordocentesis was performed and chromosome analysis revealed a 46,XY,del(4)(p14) karyotype. CONCLUSION: The prenatal detection of intrauterine growth restriction, hypospadias and foot deformity should lead doctors to suspect the presence of Wolf-Hirschhorn syndrome.

The 'tulip sign': a sonographic clue for in-utero diagnosis of severe hypospadias

OBJECTIVE

To describe a unique sonographic sign for prenatal detection of severe penoscrotal hypospadias.

METHODS

Ultrasound findings of hypospadias diagnosed in the second trimester of pregnancy in seven patients were compared with postnatal clinical features. All patients were recruited from routine sonographic examinations performed for various obstetric indications.

RESULTS

In six of the seven cases with hypospadias, a severe form of peno-scrotal hypospadias was found. In all six cases, a unique ultrasound feature was observed represented by extreme ventral angulation of the penis, with or without chordee, in a form resembling a tulip flower. This 'tulip' is formed by the ventrally bent penis located between the two scrotal folds. In all six patients, the postnatal pictures of the newborns' genitalia corresponded perfectly to the prenatal sonograms. Associated anomalies occurred in two cases, with Nager syndrome in one case and mild renal hydronephrosis in the other case.

CONCLUSIONS

The 'tulip sign' is a specific ultrasonic finding of severe hypospadias. The recognition of this may help to distinguish between severe hypospadias and other genital abnormalities (e.g. ambiguous genitalia).

Prenatal diagnosis of a rare variant of hypospadias and review of the literature

We present a case of a variant of hypospadias, diagnosed prenatally at 21 weeks' gestation, in which the penis and scrotum appeared normal but there was a cyst-like lesion and a urethrocutaneous fistula on the ventral side of the penis. Detailed sonographic examination and karyotyping confirmed this was an isolated lesion and helped the parents to decide on continuation of the pregnancy.