Further predictors of renal dysplasia in fetal obstructive uropathy: bladder pressure and biochemistry of 'fresh' urine

Urine was aspirated on two consecutive days from the dilated bladder of nine fetuses with lower urinary tract obstruction. Gestational age ranged from 17 to 35 weeks. Renal dysplasia was diagnosed histologically in four fetuses, whereas the other five had normal renal histology or only partial dysplasia. Urinary sodium (Na+) and osmolality (Osm) decreased significantly in the second urine sample 1 day after bladder emptying (median decrease: Na+ = -11.3 per cent; Osm = -13.3 per cent). Although there were no significant differences between fetuses with or without renal dysplasia, normalization of an initially raised urine Na+ concentration occurred at the second sample in a fetus with partially normal renal histology, thus correcting a false-positive diagnosis of dysplasia. Bladder pressure was measured at the time of the first urine sampling in seven fetuses and in a further eight with bladder outlet obstruction undergoing a single urine aspiration at 18-28 weeks. Bladder pressure was increased above the reference range in 8 of 15 fetuses with urinary obstruction, but there was no correlation between pressure and the degree of impairment of renal function. Although no conclusive clinical guidelines can be drawn from this study for the evaluation of fetal renal function, these findings suggest that, in lower urinary tract obstruction, tubular reabsorption is impeded by the standing pressure in the urinary tract and that improvement of renal function may occur following relief of obstruction.     

In utero surgical treatment of fetal obstructive uropathy: A new comprehensive approach to identify appropriate candidates for vesicoamniotic shunt therapy

OBJECTIVES: We present a new approach to prenatal evaluation and prediction of renal function and long-term outcomes for fetuses considered candidates for in utero surgery. STUDY DESIGN: A review of 34 cases of obstructuve uropathies was made, with analysis of our approach to prenatal evaluation, the predictive value of urinary electrolytes and protein analysis in identifying renal dysplasia, and the outcomes of cases with and without in utero surgical intervention. RESULTS: Ten of 11 pregnancies that were terminated had dysplasia; one female had cloacal dysgenesis. In three of eight unshunted cases megacystis resolved after vesicocentesis. Eight of 15 shunted fetuses survived. Of those predicted to have good postnatal outcome, six of six demonstrated good postnatal renal function. Of those predicted to have poor outcomes, two of two had poor postnatal renal function and dysplasia. Seven of 15 shunted fetuses died, four of four predicted to have dysplasia were confirmed, and three died of nonrenal causes. CONCLUSIONS: Our prenatal approach successfully differentiated fetuses with underlying renal dysplasia from those without irreversible damage who subsequently benefited from in utero vesicoamniotic shunt placement. (AM J Obstet Gynecol 1994;170:1770-9.)     

Prenatal diagnosis and postnatal outcome of congenital megalourethra. Report of two cases

We present 2 cases of congenital megalourethra diagnosed by prenatal ultrasound scan during the second trimester of pregnancy. The first one was associated with features suggesting prune belly syndrome (PBS) in contrast to the other one. Fetal urine biochemistry and fetal serum beta2-microglobulin was used to rule out severe renal impairment that would have led to postnatal renal failure soon after birth. In both cases, after extensive counselling, the parents opted against termination of pregnancy and in both cases vaginal delivery of a live neonate occurred. Postnatal follow-up demonstrated that the two infants were found to have mildly altered renal function without any physical or mental development delay. Association with features of PBS didn't seem to influence the severity of renal function impairment however, but PBS may influence parents' decision regarding termination because of additional corrective surgery and further infertility.     

Fetal intervention in obstructive uropathy: prognostic indicators and efficacy of intervention

Management of the fetus with bilateral hydronephrosis is controversial; ability to predict outcome and efficacy of prenatal intervention are unknown. We studied 40 fetuses referred for ultrasonography, examination of fetal urine, and possible therapy. We retrospectively assigned fetuses to a good prognosis group if fetal urine was hypotonic (sodium less than 100 mEq/L, chloride less than 90 mEq/L, osmolarity less than 210 mOsm/L) and there was no ultrasonographic evidence of dysplasia; we assigned fetuses to a poor prognosis group if even one criterion was abnormal. Survival was greater in the good prognosis group than in the poor prognosis group (81% vs 12.5%; 87% vs 30%, excluding abortions) (p less than 0.005). We then attempted to assess the efficacy of prenatal urinary decompression by comparing outcome within the good and poor prognosis groups. Survival with intervention was greater in both the good prognosis group and the poor prognosis group (89% vs 70% and 30% vs 0%). In 6 of the 8 survivors in the good prognosis group, severe oligohydramnios was reversed by decompression. We conclude the fetal urine electrolyte levels and ultrasonographic appear helpful in predicting residual fetal renal function and neonatal outcome and that prenatal decompression may prevent the development of fatal pulmonary hypoplasia.     

Pulmonary arterial Doppler velocimetry in fetuses with lung hypoplasia.

OBJECTIVE: The aim of the study was to examine Doppler flow velocity waveforms in the main stems of the pulmonary arteries in fetuses with autopsy-proven lung hypoplasia and to find out whether in these conditions typical patterns can be found. STUDY DESIGN: Doppler spectra were derived from the main stem of the right or left pulmonary artery in fetuses at high-risk for lung-hypoplasia. The following Doppler parameters were analyzed and compared to reference ranges: peak systolic velocity, acceleration time, time velocity integral, end-systolic reverse flow, pulsatility index (PI). Pulmonary hypoplasia was found in nine cases at autopsy after termination of pregnancy (19-23 weeks). According to etiology, three groups were considered: (A) bilateral renal malformations (n=4), (B) congenital diaphragmatic hernia (n=2), and (C) miscellaneous malformations including heart defects (n=3). RESULTS: The following Doppler parameters were found: normal values in end-systolic reversal flow in all cases, decreased peak systolic velocity and acceleration time in 3/9, decreased time velocity integral in 4/9 and increased pulsatility index in 6/9. Considering the etiology of pulmonary hypoplasia the pulsatility index was found to be the most sensitive, since all fetuses in groups A and B had an abnormal PI. CONCLUSIONS: Human fetuses with renal malformations and diaphragmatic hernia associated with lung hypoplasia show as early as 19-23 weeks of gestation an abnormal Doppler spectrum in the main stems of the pulmonary arteries. Increased PI is the best parameter to detect flow abnormality in this condition. Since the Doppler spectrum depends on cardiac anatomy and function, PI in lung hypoplasia seems to be reliable only when cardiac defects are absent.     

Differential diagnostic procedure in sonographically detected fetal cystic hygroma

A series of 5 consecutive cases of fetal cystic hygroma diagnosed prenatally in the second trimester by sonography within a year in an ultrasound screening program is presented. 3 fetuses had a 45,X karyotype, one fetus had a 47,XY,+21 chromosome constitution and in one case no cytogenetic abnormality could be found. Because there was a cleft palate present in this latter female fetus, it is possible that this was a case of the recently described malformation syndrome. 3 of the pregnancies with fetal cystic hygroma ended in spontaneous abortion, in the other 2 cases the parents decided after careful genetic counseling to have an elective termination of pregnancy. Although Turner syndrome is the most frequent finding in cases of nuchal hygroma detected in utero by ultrasound, careful sonographic and cytogenetic studies as well as a detailed family history have to be obtained to delineate the cause of the malformation. On autopsy in all 3 cases with 45,X karyotype there were streak gonads, in 2 cases an additional hypoplasia of the aortic arch was found. Amniotic fluid alpha-fetoprotein and acetylcholinesterase determinations did not prove to add any significant information to the ultrasound evaluation of fetal cystic hygroma.     

Comparison of ultrasound and autopsy findings in pregnancies terminated due to fetal anomalies

OBJECTIVE: To compare antenatal diagnoses with autopsy findings in pregnancies terminated after ultrasound detection of fetal anomalies. A second aim was to study the quality of antenatal fetal diagnosis over time. DESIGN: Retrospective, multicenter study over two consecutive six-year periods in Uppsala and Stockholm. SETTING: Cases were identified through fetal autopsy reports. SUBJECTS: Three hundred and twenty-eight fetuses from pregnancies terminated between 1992 and 2003 because of ultrasonographically diagnosed anomalies. MAIN OUTCOME MEASURES: The findings at the last ultrasound examination were compared with the autopsy reports. RESULTS: In 299 cases (91.2%) ultrasound findings either exactly matched or were essentially similar to the autopsy findings. In 23 cases (7%) ultrasound findings were not confirmed at autopsy, but the postnatal findings were at least as severe as the antenatal ones. In six cases (1.8%) termination was performed for an anomaly which proved to be less severe than was predicted by ultrasound. The number of such cases was the same in both six-year periods, while the total number of cases increased from 113 in the first to 215 in the second period. Fetal examination provided further diagnostic information in 47% of the cases. In 10% a syndrome was disclosed. CONCLUSION: Termination of pregnancy was not always based on a correct antenatal diagnosis. All fetuses but one from terminated pregnancies had evident anomalies. In six cases (1.8%) the decision to terminate was based on suboptimal prognostic and diagnostic information. Fetal autopsy by an experienced perinatal pathologist is essential to provide a definitive diagnosis.     

Prenatal sonographic chest and lung measurements for predicting severe pulmonary hypoplasia.

Pulmonary hypoplasia was diagnosed sonographically in 32 fetuses from 20 to 33 weeks of gestation. In addition to standard biometry, transverse thoracic diameter (TTD), sagittal thoracic diameter (TSD), thoracic circumference (TC) and lung diameter (LD) were measured in all cases and compared with known nomograms. The fetuses were divided into five groups according to the main sonographic findings: group 1-skeletal dysplasia; group 2-renal agenesis; group 3-diaphragmatic hernia; group 4-hydrothorax; and group 5-others. Severe pulmonary hypoplasia (PH) was diagnosed prenatally in all cases on the basis of LD measurements. In 17 (53.1 per cent) out of 32 cases TTD was below the 5th percentile while lower TSD measurements were recorded in 15 (46.8 per cent) fetuses. A thorax circumference below the 5th percentile for the respective gestational age was found in 15 cases (46.8 per cent) and a decreased LD/TC ratio in 25 cases (78.1 per cent). In 13 out of 32 fetuses pulmonary hypoplasia was diagnosed before, and in 19 cases after 24 weeks of gestation. Pulmonary hypoplasia was confirmed by autopsy in all cases. Conclusion: pulmonary hypoplasia can be sonographically detected before 24 weeks of gestation. In cases of skeletal dysplasia and renal agenesis pulmonary hypoplasia can be diagnosed by chest and lung measurements, whereas in diaphragmatic hernia and hydrothorax diagnosis of pulmonary hypoplasia is possible only by lung measurement.     

胎儿心律失常的超声心动图检测及其临床意义

目的 探讨超声心动图检测对胎儿心律失常的诊断价值及临床意义。方法 采用超声心动图对725例胎龄16-41周临床疑诊为心律失常或存在其他异常的胎儿进行检测。结果 共检出胎儿心律失常90例。其中,期前收缩72例(房性期前收缩65例,室性期前收缩7例),心动过缓9例,心动过速6例,2:1房室传导阻滞2例,心房扑动1例。4例心动过缓胎儿并发先天性心血管畸形患者,2例在随访过程中死于宫内(尸体解剖证实为单心室伴肺动脉瓣狭窄1例,心脏横纹肌瘤1例),2例终止妊娠(尸体解剖证实为二尖瓣闭锁1例,共同房室通道1例)。1例胎龄38周心房扑动胎儿经吸氧及严密监护24h后,心律失常无缓解,立即行剖宫产术,出生后应用西地兰后心律转为窦性。其余85例胎儿心律失常均为阵发性,不伴有胎儿心脏形态、结构畸形及胎儿水肿,均足月出生,出生后听诊均未闻及心脏杂音及心律失常。结论 胎儿超声心动图是产前检查胎儿心律失常的可靠的无创性影像技术,其应用有助于早期检出并指导心律失常胎儿的处理。     

Significant fetal-maternal hemorrhage after termination of pregnancy: implications for development of fetal cell microchimerism

OBJECTIVE: Recent reports that an association exists between fetal cell microchimerism and autoimmune disease has increased interest in the postpartum persistence of fetal cells. The purpose of this study was to determine, by means of quantitative polymerase chain reaction amplification, whether a significant fetalmaternal hemorrhage occurs after elective termination of pregnancy. STUDY DESIGN: Blood samples were obtained from 23 women who underwent termination of pregnancy immediately before venipuncture; these samples were subjected to analysis by quantitative polymerase chain reaction amplification with the use of Y-chromosome primers. There were 21 male and 2 female fetuses. Results were equilibrated to 16 mL and analyzed by a weighted linear regression analysis to evaluate the correlation between detected fetal nucleated cell equivalents and gestational weeks. RESULTS: Among the 21 known male fetuses, the median number of detected fetal nucleated cell equivalents was 1552 (range, 50-37,618). The female fetuses had no fetal nucleated cell equivalents detected. A positive dependence of male fetal nucleated cell equivalents on gestational age was shown (P <.001). CONCLUSION: Analysis by quantitative polymerase chain reaction amplification demonstrated a large fetal-maternal transfusion after elective abortion. Consideration of the biologic consequences of pregnancy and the potential for future development of fetal cell microchimerism must now extend to a larger population of women.     

MR autopsy in fetuses.

OBJECTIVE: The purpose of this study was to determine whether postmortem magnetic resonance imaging (MR autopsy) could serve as an alternative to necropsy of fetuses. The value of MR autopsy in the validation of the obstetric management and in risk counseling concerning future pregnancies is discussed. METHODS: 10 consecutive, malformed fetuses were examined by postmortem MRI within 24 h of delivery. Prenatal ultrasound (US) was performed in all fetuses. Complete necropsy served as gold standard. RESULTS: MR autopsy confirmed every US diagnosis responsible for termination. All MRI findings were confirmed by necropsy. In two fetuses, necropsy gave additional information relevant for risk counseling. Histologic examination corrected the diagnosis in one case. CONCLUSIONS: MR autopsy provides valuable information previously only available from necropsy. In parents who refuse perinatal necropsy, the information obtained by MR autopsy can be used to validate obstetric management and to evaluate the risk for future pregnancies. Necropsy however remains the gold standard.     

Size of the fetal adrenal in bilateral renal agenesis

Bilateral renal agenesis is a fetal malformation incompatible with extrauterine life. Accurate prenatal diagnosis is essential for patient counseling. False-negative diagnoses have been reported and were attributed to the sonographic misidentification of apparently hypertrophied fetal adrenal glands as fetal kidneys. To study the relationship between renal agenesis and adrenal size, we reviewed autopsy records from 11 affected fetuses that had undergone careful autopsy and organ weight determination in our laboratory. Anomalies of distant structures were present in five affected fetuses. A sonographic diagnosis of adrenal hypertrophy had been made in two cases. In four of 11 fetuses, the glands had taken on a flattened discoid appearance. The autopsy records of 240 normal fetuses were similarly reviewed, and regression lines were generated for adrenal weight based on foot length and crown-rump length. The adrenal weights from affected fetuses were well within normal limits when compared with these normal regression lines and with organ weight standards from the literature. We conclude that adrenal hypertrophy is not a common finding in this syndrome and that the reported false-negative diagnoses are more likely attributable to a change in adrenal shape rather than a true increase in adrenal mass.     

Diagnosis and outcome of fetal lower urinary tract obstruction in the northern region of England

OBJECTIVE: We reviewed the prenatal and postnatal management of fetal lower urinary tract obstruction (LUTO) in a large geographically defined population. METHODS: The records of 113 cases of LUTO seen over a 14-year period were examined. The predictive accuracy of prenatal findings for chronic renal failure (CRF) and a comparison of prenatal-suspected and non-suspected cases were made. RESULTS: The incidence of LUTO was 2.2 in 10 000 births. During the study period, prenatal detection improved from 33 to 62%. Sensitivity of prenatal ultrasound detection of renal dysplasia and fetal urinary sodium, calcium, and beta2-microglobulin for CRF or renal dysplasia on autopsy were 59, 33, 66, and 63% respectively. Compared to undetected cases, those detected prenatally had higher mortality and a higher rate of CRF at 24 months (17% vs 57%, p < 0.01). CONCLUSION: Our observations confirm the poor prognosis associated with fetal LUTO. The value of serial fetal urine biochemistry, other prenatal predictors of postnatal renal function, and the benefits of vesicoamniotic shunting require larger series and longer follow-up.     

Prenatal diagnosis of Meckel syndrome: a case report.

OBJECTIVE: To demonstrate the major sonographic findings associated with Meckel syndrome and to emphasize the importance of prenatal sonography in helping to establish the correct diagnosis. SUBJECTS: Two fetuses with prenatal diagnosis of Meckel syndrome were sonographically evaluated. RESULTS: Both fetuses were demonstrated to have evidence of renal cystic dysplasia, occipital cephalocele and postaxial polydactyly. One case was diagnosed at 16 weeks of gestation whereas the other was detected at 36 weeks. Of interest, the first case had only unilateral renal cystic dysplasia and contralateral renal agenesis and mild degree of oligohydramnios. The other related anomalies which were not detected prenatally included cerebellar hypoplasia in case 1 and micrognathia in case 2. CONCLUSION: The main sonographic findings included renal cystic dysplasia, occipital cephalocele and postaxial polydactyly.     

Effect of amniotomy on uteroplacental and fetoplacental flow velocity waveforms

Artificial rupture of fetal amnionic membranes is frequently performed in normally progressing spontaneous labor, although the maternal and fetal effects of the procedure have not been clearly defined. The effect of elective amniotomy on placental impedance to blood flow in the umbilical artery and arcuate branches of the uterine artery was determined by analysis of blood flow velocity waveforms (FVWs) recorded with continuous wave Doppler ultrasound in 15 pregnant women at term. All patients were in spontaneous, normally progressing labor after an uneventful pregnancy. Electronic fetal heart rate monitoring and real-time ultrasound examination of the fetuses were unremarkable. FVWs were obtained immediately before and after amniotomy. Fourteen patients progressed to spontaneous vaginal delivery, and one patient underwent repeat cesarean section for arrest of dilation in the active phase of labor. No maternal, fetal, or neonatal complications were recorded. Calculated mean systolic/diastolic ratios of FVWs obtained before and after amniotomy were compared by means of Wilcoxon's signed rank test, and no significant differences were found. We conclude that early elective amniotomy exerts no demonstrable deleterious effect on impedance to uteroplacental or fetoplacental blood flow in healthy women at term.     

Correlation between prenatal diagnosis by ultrasound and fetal autopsy findings in second-trimester abortions

We evaluated the correlation between prenatal diagnosis by ultrasound and autopsy findings, based on 52 second-trimester pregnancies terminated due to fetal malformations or chromosome aberrations diagnosed at a gestational age of 12-25 weeks. In 24 pregnancies, there was full agreement between ultrasound and autopsy. In 23 fetuses, the main diagnosis was confirmed and additional or more specific findings were observed on autopsy. In five fetuses, there were considerable differences. Discrepancies between ultrasound and autopsy findings were mainly anomalies undetectable by ultrasound and thus expected; however, about one-third of the discrepancies were not expected, representing findings that were 'missed' at ultrasound. The main ultrasound diagnoses were confirmed in the majority of the pregnancies, but the additional information obtained at autopsy in more than half of the fetuses clearly shows the value and benefit of postmortem fetal examination following termination of a pregnancy.     

产前超声诊断双胎反向动脉灌注综合征

目的 探讨多普勒超声在产前诊断双胎反向动脉灌注综合征(TRAP)中的临床价值,提高对此类罕见畸形的认识. 方法 我院1995年1月至2008年9月产前超声诊断及疑似诊断19例TRAP,比较超声与生后随访或引产后病理结果. 结果 19例TRAP中,无心畸胎(受血儿)均有严重结构畸形,产前超声对胎儿皮肤水肿、脊柱、腹腔结构及下肢显示准确性高;但对头颅发育不良及特别短小的上肢显示困难,颜面部畸形基本上显示不清.泵血儿(供血胎)中死胎及死产16例,存活3例;心功能不全9例.胎儿附属结构特征:(1)存活的无心畸胎均为脐动脉供血,血流方向朝向胎儿体内,与正常胎儿脐动脉血流方向相反;(2)两胎儿脐带胎盘附着处可见大的血管相交通;(3)无心畸胎多为单脐动脉;(4)羊水过多为预后不良征象;(5)单羊膜囊双胎常发生脐带缠绕及打结. 结论 多普勒超声可为评价TRAP血流动力学特征、评估泵血儿心功能、附属物异常及预后提供重要信息,为产前诊断TRAP的首选和重要的诊断方法.     

产前超声诊断双胎反向动脉灌注综合征

目的 探讨多普勒超声在产前诊断双胎反向动脉灌注综合征(TRAP)中的临床价值,提高对此类罕见畸形的认识. 方法 我院1995年1月至2008年9月产前超声诊断及疑似诊断19例TRAP,比较超声与生后随访或引产后病理结果. 结果 19例TRAP中,无心畸胎(受血儿)均有严重结构畸形,产前超声对胎儿皮肤水肿、脊柱、腹腔结构及下肢显示准确性高;但对头颅发育不良及特别短小的上肢显示困难,颜面部畸形基本上显示不清.泵血儿(供血胎)中死胎及死产16例,存活3例;心功能不全9例.胎儿附属结构特征:(1)存活的无心畸胎均为脐动脉供血,血流方向朝向胎儿体内,与正常胎儿脐动脉血流方向相反;(2)两胎儿脐带胎盘附着处可见大的血管相交通;(3)无心畸胎多为单脐动脉;(4)羊水过多为预后不良征象;(5)单羊膜囊双胎常发生脐带缠绕及打结. 结论 多普勒超声可为评价TRAP血流动力学特征、评估泵血儿心功能、附属物异常及预后提供重要信息,为产前诊断TRAP的首选和重要的诊断方法.     

The sonographic diagnosis of Dandy-Walker and Dandy-Walker variant: associated findings and outcomes

Outcomes of pregnancies with sonographically diagnosed Dandy-Walker (DW) or Dandy-Walker variant (DWV) syndromes vary widely. We examined our own experience with these diagnoses in an effort to identify those sonographic features that best predicted neonatal outcome. We identified 50 fetuses with DW and 49 with DWV diagnosed sonographically. Eighty-six per cent of fetuses with DW and 85% of fetuses with DWV had other sonographically identifiable anomalies, the most common being ventriculomegaly (DW: 32%; DWV: 27%) and cardiac defects (DW:38%; DWV: 41%). Forty-six per cent and 36% of available karyotypes in cases of DW and DWV, respectively, were abnormal. 50 out of 99 women in our series elected pregnancy termination. Only three pregnancies with DW resulted in a living infant, and only one of these had a normal paediatric examination at six-week follow-up. Thirteen out of 49 infants with DWV survived the neonatal period and 7 of 13 were reported initially as normal infants, including six with an isolated finding of DWV. We conclude that overall, the prognosis for these posterior fossa defects is grim but not uniformly fatal. The presence of other anomalies is associated with the worst prognosis. Isolated Dandy-Walker variant has the highest chance of leading to a normal neonate.