Prenatal diagnosis of sirenomelia

Sirenomelia sequence associates a fusion of inferior legs with renal anomalies until bilateral agenesis. It is a rare and lethal polymalformation. The purpose of the ultrasonographic study is to identify the sirenomelia as early as possible during pregnancy and to differentiate it from caudal regression syndrome. A case of sirenomelia diagnosed early is reported together with a review of the literature. The ultrasonographic diagnosis, associated defects, the interest of color Doppler study of abdominal vasculature are discussed. Antenatal ultrasonographic diagnosis should be obtained as early as possible, before 20th gestational week at the latest. Color Doppler is helpful to confirm the diagnosis in case of bilateral renal agenesis. The main differences between sirenomelia and caudal regression syndrome (which requires a very different genetic counselling) are summarized in a table.     

Accuracy of prenatal diagnosis of renal agenesis with color flow imaging in severe second-trimester oligohydramnios

OBJECTIVE: Our purpose was to examine the potential of color flow imaging to assess the presence of renal arteries in second-trimester pregnancies complicated by severe oligohydramnios.STUDY DESIGN: Thirty-three consecutive second-trimester pregnancies referred with severe oligohydramnios were prospectively studied with high-resolution color Doppler ultrasonography to establish the presence or absence of renal arteries. Prenatal findings were correlated with the presence or absence of fetal kidneys at postmortem or postnatal examination.RESULTS: Neither renal artery was visualized in eight fetuses; postmortem examination confirmed bilateral renal agenesis in seven and unilateral renal agenesis with a contralateral atrophic multicystic kidney in the other. Only one renal artery was seen in three; postmortem examination demonstrated unilateral renal agenesis in two fetuses and bilateral multicystic dysplastic kidneys in the other. Postmortem or postnatal evaluation confirmed the presence of both kidneys in all 22 fetuses in which both renal arteries were identified prenatally.CONCLUSIONS: Color Doppler ultrasonography is useful in the prenatal evaluation of fetuses with severe second-trimester oligohydramnios to demonstrate the presence or absence of renal arteries. This technique should be added to the armamentarium of prenatal tests to evaluate second-trimester fetuses with severe oligohydramnios.     

The BOR syndrome and renal agenesis--prenatal diagnosis and further clinical delineation

This is the first report of prenatal diagnosis of a fetus with brachio-oto-renal dysplasia (BOR) syndrome with right-sided renal agenesis and severe left hypoplasia. The father of this fetus had malformed external ears, a left-sided preauricular pit and branchial cyst, and bilateral mild to moderate deafness without a demonstrable renal anomaly. This family highlights the variable expressivity seen in the autosomal dominant BOR syndrome, the importance of genetic counselling for families with BOR syndrome, and the aetiologic heterogeneity of renal agenesis.     

Short rib polydactyly syndrome — a rare skeletal dysplasia

We present a case of prenatal ultrasonographic diagnosis of short rib polydactyly syndrome (SRPS). The fetus had severe oligohydramnios due to bilateral renal agenesis. Amnioinfusion with normal saline improved ultrasound visualization and helped in confirming the diagnosis. Subtypes and differential diagnosis of SRPS are discussed.     

Bilateral renal agenesis (Potter's syndrome) in two consecutive infants.

Bilateral renal agenesis is a relatively rare congenital anomaly; its frequency is 1 : 3000-4000 deliveries, with a remarkable predominance of male infants. This anomaly is most often found in combination with characteristic facial features ('Potter's face') and pulmonary hypoplasia, the combination being known as Potter's syndrome. In the course of pregnancy an increasing oligohydramnios becomes manifest; during labor, virtual absence of amniotic fluid is found in most cases. This oligohydramnios should alert the obstetrician to suspect Potter's syndrome; serial ultrasonography may confirm the diagnosis. Most affected children are born alive but die within a few hours due to respiratory difficulties caused by the pulmonary hypoplasia. Despite the remarkable facial characteristics of these infants, it was only in a small minority that the diagnosis was considered before autopsy. This stresses the need for a full post-mortem examination in all cases of perinatal death. The etiology is still uncertain, though multifactorial inheritance is the most likely. As a consequence, the recurrence risk is not negligible; the small number of 'familial occurrence' observations, however, does not allow estimation of a risk figure. Genetic counseling is indicated in any family giving birth to a child with bilateral renal agenesis. A family is described in which two consecutive male infants with bilateral renal agenesis were born alive and survived 19 and 38 h.     

Recurrent bilateral renal agenesis

Bilateral renal agenesis is usually a sporadic occurrence; recurrence in the same family is rare. A case of recurrent bilateral renal agenesis is presented.     

First-trimester diagnosis of sirenomelia. A case report

We report a case of sirenomelia diagnosed at 13 gestational weeks. This rare malformation sequence is characterized by fusion and rotation of the lower limbs to various degrees and anorectal atresia, usually associated with absence of bladder and agenesis or dysgenesis of the kidneys. Diagnosis is commonly made later in the second trimester of pregnancy with oligohydramnios as the alerting sign. Survival is extremely rare, and only possible in the absence of bilateral renal agenesis. In view of the dismal prognosis, early diagnosis allows for earlier and less traumatic therapeutic abortion.     

Oligohydramnios and fetal cerebral blood flow

Summary. Blood flow velocity waveforms in the fetal internal carotid artery were recorded in five pregnancies complicated by prolonged severe oligohydramnios due to bilateral renal agenesis. End-diastolic flow velocity was reduced, absent or even reversed, resulting in a raised pulsatility index in all five cases. These data suggest that prolonged severe oligohydramnios may hamper cerebral blood flow through fetal head compression.     

First trimester diagnosis of sirenomelia: a case report and review of the literature

Sirenomelia sequence is a rare lethal pattern of congenital anomalies characterized by a number of hallmark skeletal anomalies, including fusion of the lower extremities or a single lower limb, bilateral renal agenesis or dysgenesis with absent or hypoplastic renal arteries, oligohydramnios, and the presence of aberrant vasculature. The etiology is still controversial. Prognosis is very poor, with the babies being stillborn or succumbing soon after birth. In the second trimester, oligohydramnios due to renal agenesis makes the diagnosis of sirenomelia difficult. Conversely, in the first trimester, the amniotic fluid volume is usually normal, unrelated to the fetal urine production. Therefore, a first-trimester or early second trimester anatomic survey of the fetus is proposed as preferable and more accurate for the diagnosis of this rare anomaly. In this article, we report a case of sirenomelia detected by two- and three-dimensional ultrasound in the 11th week of gestation and the associated literature is discussed.     

Role of transvaginal sonography in the diagnosis of bilateral renal agenesis.

Bilateral renal agenesis with lethal pulmonary hypoplasia, characteristic facial abnormalities, and limb deformities is a relatively common congenital defect. However, it is rarely diagnosed antenatally because of the virtual absence of amniotic fluid. We report the use of transvaginal sonography in diagnosing two cases of bilateral renal agenesis antenatally.     

Mosaic trisomy 11 in a fetus with bilateral renal agenesis: co-incidence or new association?

We report a fetus with mosaic trisomy 11 who also had bilateral renal agenesis. We describe the post-mortem examination findings in the fetus and cytogenetic analysis. There are no earlier reports of full trisomy 11, presumably because it is lethal and results in early spontaneous miscarriages. There is only one report published earlier in a fetus with mosaic trisomy 11. There have been a few case reports of trisomy 11 identified in pre-natal samples, where it was associated with normal outcome. Bilateral renal agenesis has not been reported earlier in association with mosaic nor non-mosaic trisomy 11. We describe this rare cytogenetic finding in a fetus with bilateral renal agenesis. We also discuss the issues around genetic counselling when this is encountered in clinical practice.     

Transvaginal Doppler color flow mapping

Transvaginal Doppler color flow mapping was performed on 8 Japanese women (normal, 1; menopause, 2; uterine myoma, 1; endometriosis, 2; pregnant, 2). In all 8, bilateral uterine arteries and branches could be clearly identified in shades of blue and/or red. The color flows were abundant in the pregnant women. Transvaginal Doppler color flow mapping is expected to be an important diagnostic tool for assessing uterine arterial blood flows in physiologic and pathologic conditions of the pelvis.     

Prenatal diagnosis of del(15)(q26.1) and del(18)(q21.3) due to an unbalanced de novo translocation: ultrasound, molecular cytogenetic and autopsy findings

A case of partial deletion of the distal parts of chromosomes 15 and 18 [(15)(q26.1)(18)(q21.3)] due to a de novo translocation is reported. Cordocentesis and fetal karyotyping was done because of severe oligohydramnios and bilateral absence of kidneys. Renal defects are a frequent finding in fetuses with different chromosomal anomalies; this particular chromosomal rearrangement however has not been reported yet in a fetus with bilateral renal agenesis. FISH was performed for detailed clarification of the chromosomal anomaly. Prenatal karyotyping appears to be important in fetuses with renal agenesis.     

Gestational hypertension and preeclampsia associated with unilateral renal agenesis in women with uterine malformations

OBJECTIVE: To evaluate the possible connection between gestational hypertensive disorder and unilateral renal agenesis in women with congenital uterine anomalies. STUDY DESIGN: Thirty-three (16%) out of 206 women with uterine anomalies had unilateral renal agenesis. Nineteen of them had delivered and comprised the study group. The control group consisted of 44 women among the 206 with similar uterine malformations who had normal bilateral kidneys and matched in age and parity with the study group. Retrospective analysis considered the presence of gestational hypertension, proteinuria, preeclampsia, perinatal outcomes and manifestations of hypertension and renal disease during the follow-up period in both groups. The median follow-up was 166 months (range 24-372 months). RESULTS: Women with unicornuate uterus most frequently (25%) evinced unilateral renal agenesis. Eight (42%) out of 19 women with malformed uterus and unilateral renal agenesis had in at least one pregnancy gestational hypertension, preeclampsia or gestational proteinuria compared to 8 (18%) out of 44 women with two kidneys (relative risk, RR 2.33, 95% CI 1.02, 5.29). Seventeen (35%) out of all 49 pregnancies in the study group were complicated by gestational hypertensive disorder or proteinuria as against 10 (11%) out of 90 pregnancies in the control group (RR 3.12, 95% CI 1.55, 6.28). Perinatal outcomes were similar in both groups. During follow-up none had diagnosed proteinuria or chronic renal disease, but two out of 19 women (11%) with unilateral renal agenesis had commenced medication for chronic hypertension. CONCLUSION: Unilateral renal agenesis predisposes women with uterine anomalies to preeclampsia.     

Trisomy 10: ultrasound features and natural history after first trimester diagnosis

We report on the ultrasound features and natural history of trisomy 10. At 12 weeks' gestation in a routine scan examination, the fetus presented with increased nuchal translucency thickness, mild skin oedema, bilateral pleural effusion, marked micrognathia, cardiomegaly, unilateral talipes and reversed A-wave in the ductus venosus blood flow. Karyotyping on chorionic villus sampling (CVS) led to the diagnosis of trisomy 10, which was confirmed by fetal blood sampling at 22 weeks' gestation. As the parents opted to continue with the pregnancy, the natural history and following ultrasound features are described. This is the third case of trisomy 10 in the literature reporting on the physical features. The most frequent ultrasound findings presented in trisomy 10 are increased nuchal translucency, micrognathia, renal agenesis, facial cleft, limbabnormalities, cardiac defects and early severe growth retardation.     

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)     

Sirenomelia--a rare cause of an oligoanhydramnion in the second trimester--a case report

Sirenomelia is a rare, but complex and lethal malformation. It is caused by a primary defect of the caudal axial skeleton and damage to the primary streak, which appears due to a vascular steal phenomenon. Sirenomelia appears sporadic with an incidence of 1-64,000 births. A risk for sirenomelia can be also found in patients with poorly controlled diabetes mellitus and in monocygotic twins. Leading ultrasound findings are fusioned lower extremities, bilateral renal agenesis, single umbilical artery and a distinct oligohydramnios. 3D ultrasound and color Doppler sonography can additionally be used for diagnostic, as well as amnioninfusion. There are 3 forms of sirenomelia, depending on missing or presence of the feet it is distinguished as sympus apus, monopus or dipus. We are presenting a case of sirenomelia with sympus dipus, which was transferred for further diagnostic of severe oligohydramnios in 21 weeks of gestation by the gynecologist.     

Recurring bilateral renal agenesis diagnosed by ultrasound with the aid of amnioinfusion at 18 weeks' gestation.

Recurrent bilateral renal agenesis in siblings is very rare. Presented is a case diagnosed with sonographically aided amnioinfusion at 18 weeks in a woman with an infant affected with the same condition in a previous pregnancy.     

Prenatal diagnosis of sirenomelia

OBJECTIVE: What kind of diagnostical methods are usual to detect fetal sirenomelia? MATERIAL AND METHODS: The prenatal diagnosis of fetal sirenomelia combined with bilateral renal agenesis, oligohydramnios and single umbilical artery in a 24-year-old woman, gravida 2, para 1, at a gestational age of 18 + 3 weeks is described in this case report. RESULTS: This fetal malformation was an accidental sonographic found, and caused after confirming diagnosis by amnoinfusion and amniocentesis, the termination of pregnancy. Genetic examination revealed tetrasomia 13. CONCLUSIONS: The sonographic finding of oligohydramnios should cause an exactly sonographical examination with amnioinfusion. In case of sirenomelia genetical examination is necessary.     

Magnetic resonance imaging in the evaluation of uterus didelphys with obstructed hemivagina and renal agenesis: a case report

Uterus didelphys with obstructed hemivagina and ipsilateral renal agenesis usually presents after menarche with progressive abdominal pain during menses secondary to hematocolpos. Initially, the anomaly remains unrecognized, while patients most frequently referred to surgeons for assistance. The method of choice for diagnosis is magnetic resonance imaging. A greater awareness of the syndrome of uterus didelphys, obstructed hemivagina and ipsilateral renal agenesis should lead to its prompt diagnosis, allowing for early and appropriate surgical treatment as well as decreased long-term morbidity. Transvaginal excision of the septum is the appropriate mode of treatment.