Severe uropathy and normal amniotic fluid volume in a male fetus: sonographic surveillance leading to the diagnosis of megacystis-microcolon-intestinal hypoperistalsis syndrome

The widespread use of sonography as a screening tool for fetal anomalies has facilitated prenatal detection of several fetal conditions characterized by urinary tract dilatation. These conditions are more common in male fetuses and are generally a result of an anatomic defect causing obstruction along the urinary tract system. Although the prognosis of these conditions largely depends on the specific anomaly, several poor prognostic factors have been described. These factors include detection at an early gestational age, bilateral marked dilatation, a persistently obstructed bladder, oligohydramnios causing pulmonary hypoplasia, and the presence of associated fetal or chromosomal anomalies. We report a case in which a male fetus at 14 weeks' gestation had a diagnosis of rapidly progressing bilateral hydronephrosis, massive bladder dilatation, hydroureter, and a surprisingly normal amniotic fluid volume. Serial sonographic surveillance assisted us in obtaining the correct diagnosis, which was important for adequately consulting the patient regarding the fetal prognosis in the affected index pregnancy as well as the likelihood of recurrence in future gestations.     

Early determination of fetal sex using transvaginal sonography: technique and pitfalls

Transvaginal sonography (TVS) enables sex determination at an early stage of pregnancy. The morphologic features of fetal external genitalia at 13 weeks to 16 weeks, menstrual age, are different from those seen later in pregnancy; therefore an attempt to determine fetal gender at this early stage by the same criteria as those used later is hazardous, especially for determining the male sex. The main diagnostic criteria for male gender determination by TVS are the "dome" sign representing the sonographic visualization of the fetal scrotum, the cranially directed phallus, and the longitudinal raphe at the base of the penis. The diagnostic criteria for female gender are the 2 or 4 parallel lines representing the labial folds and the caudally directed phallus (clitoris). The length of the fetal phallus at this early stage is not diagnostic and may be the main pitfall to the unexperienced sonographer. Between weeks 13 and 14 sex diagnosis was possible in 130/171 pregnancies (76%) in our first 2 years and 188/235 (80%) in our last 2 years of experience. Between weeks 15 and 16 sex diagnosis was possible in 122/139 pregnancies (88%) during our first 2 years and 96.7% (528/546) during the last 2 years of experience. The accuracy rate for fetal male gender identification increased from 91.7% during the first 2 years of TVS experience to 99.7% during the last 2 years of TVS experience, and the accuracy rate for female gender identification, increased from 93.3% to 100%, respectively, applying the above criteria and based on acquired experience of early fetal sex identification by TVS early in gestation. Early and precise determination of fetal sex is possible and might avoid invasive procedures such as amniocentesis.     

Complementary Roles of Sonography and Magnetic Resonance Imaging in the Assessment of Fetal Urinary Tract Anomalies

Objective. The purpose of our study was to determine whether fetal magnetic resonance imaging (MRI) provides additional information that might affect the obstetric management of pregnancies complicated by sonographically diagnosed fetal urinary tract anomalies. Methods. Fetal MRI and sonography were used to study 39 women with suspected fetal urinary tract anomalies in the second and third trimesters of pregnancy. Results. In 24 of 39 cases (61%), fetal MRI confirmed the sonographic diagnosis. In 14 cases (36%), fetal MRI modified the initial sonographic diagnosis and counseling but did not change obstetric management. In 1 case (3%), the addition of fetal MRI resulted in a substantial change in the management of the pregnancy. Conclusions. During the second and third trimesters of pregnancy, fetal MRI showed fetal urinary tract anomalies in excellent anatomic detail. Fetal MRI is a useful complementary tool in the assessment of sonographically diagnosed fetal urinary tract anomalies. In a small percentage of cases, it can have a substantial impact on obstetric management.     

Antenatal three-dimensional sonographic features of early amnion rupture sequence

Background: Early amnion rupture sequence is rare, and its antenatal three-dimensional sonographic features have not been reported.Case: A 24-year-old japanese woman, gravida 1, para 0, was referred to our sonography clinic during her 16th week of gestation because of multiple fetal anomalies. Three-dimensional sonography clearly showed scalp adhesion, skull defect, abdominal wall disruption, amputation of the right hand, kyphoscoliosis, and clubfeet. Delivery was induced at 17 weeks of gestation. Autopsy showed a 166 gram male fetus and confirmed the prenatal diagnosis of early amnion rupture sequence.Conclusion: Three-dimensional sonography provides further information for sonographers. This includes unique identification of the displayed anatomic plane, realistic and reliable depiction of multiple fetal anomalies, and visualization of complex fetal anomalies.     

Value of a complete sonographic survey in detecting fetal abnormalities: correlation with perinatal autopsy.

OBJECTIVE: To determine the sensitivity of using a complete anatomic sonographic survey in detecting fetal abnormalities via correlation with perinatal autopsy results. METHODS: All perinatal autopsies (1994-2001) with positive findings for at least 1 fetal abnormality and performed by a single perinatal pathologist at our institution were retrospectively reviewed. From these cases, singleton fetuses who received prenatal sonography solely in our unit were identified. The sensitivity of sonography in detecting anomalous fetuses as well as fetal abnormalities and abnormalities by organ system was determined. Abnormalities were classified as major or minor In addition, findings from sonography and autopsy were compared, and their correlation was assigned to 1 of 3 categories. RESULTS: Of 88 fetuses identified, 85 had 1 or more abnormal structural sonographic findings (sensitivity for fetuses with anomalies, 97%). A total of 372 separate abnormalities were found on autopsy; of the 299 major and 73 minor abnormalities, prenatal sonography showed 224 (75%) and 13 (18%), respectively. There was either complete agreement or only minor differences between sonographic and autopsy findings in 57 (65%) of 88. The sensitivity of sonography in identifying abnormalities was greater than 70% in these systems: central nervous system, cardiac system, urinary system, extremities, genitalia, ribs, and hydrops. CONCLUSIONS: In experienced hands, sonography has 97% sensitivity in detecting anomalous fetuses when compared with perinatal autopsy results. Although the sensitivity of sonography in detecting major fetal abnormalities is 75%, the sensitivity for minor abnormalities is poor, even when using a complete anatomic sonographic survey. Although it has limitations, this type of survey is invaluable for both patients and physicians in diagnosing fetal abnormalities.     

胎儿泌尿系畸形的产前超声诊断及预后评估

目的 探讨超声诊断胎儿泌尿系畸形的声像图特征及其临床实用价值。 方法 按产科超声常规检查胎儿，发现胎儿泌尿系统异常者，根据声像图特征评估处理。 结果 52例产前超声可疑为泌尿系畸形患者中，13例考虑到泌尿系畸形可能为致命性病变而终止妊娠，10例因一侧肾病变而自愿引产，12例胎儿出生后随访肾盂积水消失，7例胎儿肾盂扩张大于1．5cm，考虑输尿管狭窄出生后经手术治疗，1例胎儿单侧肾囊肿因合并心脏严重畸形出生后死亡，8例胎儿一侧肾脏异常、另一侧形态及结构未发现异常后均自然分娩，1例胎儿于孕24周可疑婴儿型多囊肾后经复查排除。 结论 产前超声诊断胎儿泌尿系畸形，依靠特有的声像图改变及合并其他畸形，对胎儿预后判断、临床及早采取措施提供依据，这对优生优育及新生儿早期治疗有重要临床实用价值。     

Sonographic diagnosis of urethral anomalies in infants: value of perineal sonography.

OBJECTIVE: To assess the value of urethral sonography including a perineal approach in evaluating urethral anomalies in infants. METHODS: A radiology database review identified 88 patients (mean age +/- SD, 64 +/- 84 days) who underwent voiding cystourethrography (VCUG) and urethral sonography as part of extended sonography of the urinary tract. Sonographic and VCUG images and reports were reviewed to assess agreement between both modalities for detection of urethral anomalies. RESULTS: Sonography facilitated the correct diagnosis of all 3 posterior urethral valves. The only urethral diverticulum, the only ectopic ureteric insertion into the urethra, the only urogenital sinus, and the only urethrovaginal fistula were also shown on sonography. In 73 (94%) of 78 cases, sonography correctly showed the absence of anomalies. In 5 infants, sonography could not reliably assess the urethra and showed indirect signs of urethral anomalies; however, these patients had normal urethras on VCUG. CONCLUSIONS: Our data show that sonography of the urethra is a valuable tool for diagnosis of urethral anomalies. Especially, negative findings on sonography are highly suggestive of the absence of urethral anomalies. Positive or equivocal sonographic findings should indicate VCUG.     

Enlarged fetal bladder: Differential diagnosis and outcomes

The sonographic finding of an enlarged fetal bladder may simply be a transitory normal variant, but it may also be secondary to reflux or to obstructive, neurogenic, or myopathic causes. In this report, we describe the cases of 3 fetuses with an enlarged bladder, each of which had a different cause. The first fetus had posterior urethral valve obstruction, the second, a ruptured neurogenic bladder, and the third, megacystic-microcolon-intestinal hypoperistalsis syndrome. When sonographic examination reveals an enlarged fetal bladder, the ureter, kidneys, genitalia, and spine should be evaluated carefully. Although sonography is good at identifying urinary tract abnormalities, it often cannot provide the specific diagnosis or cause. We recommend frequent sonographic monitoring to evaluate such fetuses for persistence of or changes in bladder enlargement and for changes in the volume of amniotic fluid because these signs may be indicators of abnormalities of renal function and risk factors for a poor prognosis. Analysis of fetal electrolyte levels can also aid in determining the prognosis and whether the condition is amenable to therapeutic intervention.     

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

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

Sonographic markers of fetal trisomies: second trimester.

OBJECTIVE: Second-trimester sonographic findings of fetal trisomy may include structural abnormalities or sonographic markers of fetal aneuploidy. Unlike structural anomalies, sonographic markers of fetal aneuploidy are insignificant by themselves with regard to outcome, are nonspecific--most frequently seen in normal fetuses, and are often transient. Our objective was to review the second-trimester sonographic findings of the major trisomic conditions, trisomies 13, 18, and 21. METHODS: We reviewed a number of the most commonly accepted markers, including nuchal thickening, hyperechoic bowel, echogenic intracardiac focus, renal pyelectasis, shortened extremities, mild cerebral ventricular dilatation, and choroid plexus cysts. Markers associated with trisomy 21 were emphasized. RESULTS: The sensitivity of sonography for detection of fetal trisomic conditions varies with the type of chromosome abnormality, gestational age at the time of sonography, reasons for referral, criteria for positive sonographic findings, and the quality of the sonography. As an estimate, 1 or more sonographic findings can be identified in approximately 90% of fetuses with trisomy 13, 80% of fetuses with trisomy 18, and 50% to 70% of fetuses with trisomy 21 (Down syndrome). CONCLUSIONS: The presence or absence of sonographic markers can substantially modify the risk of fetal Down syndrome and is the basis of the so-called genetic sonogram. Because maternal biochemical and sonographic markers are largely independent, combined risk estimates will result in even higher detection rates than either alone.     

Sonographic findings and fetal chromosomal studies undertaken prenatally by fetal blood sampling using cordocentesis.

Prenatal karyotyping was carried out on 206 pregnancies with sonographic abnormalities, including fetal malformations, growth retardation and disorders of the amniotic fluid volume. Overall, chromosomal aberrations were detected in 37 cases (18.0%), but the frequency of chromosomal aberrations was 8.2% in fetuses with a single anomaly and 52.7% in fetuses with multiple anomalies. The chromosomal risk was very high in malformations associated with growth retardation (81.8%) or with both growth retardation and disorders of the amniotic fluid volume (82.4%). High rates of chromosomal aberrations were observed in cases of heart anomalies, diaphragmatic hernia, urinary tract obstruction, hydrocephalus, intestinal atresia, abdominal wall defect and fetal effusion/hydrops. In fetuses at high risk of chromosomal aberrations, cordocentesis for rapid karyotyping is justified in the second or third trimester.     

Prenatal diagnosis of trisomy 13: analysis of 28 cases.

OBJECTIVE: The purpose of this study was to investigate the role of second-trimester sonographic examination in the prenatal diagnosis of trisomy 13. METHODS: Of 22,150 fetal chromosome analyses, 28 fetuses with trisomy 13 were found between 1990 and 2004. Sonographic findings of this aneuploidy were analyzed in this study. RESULTS: The average maternal age was 32.4 years; the average gestational age was 19.5 weeks. There was an 89.3% (n = 25) total prevalence of sonographic abnormalities in fetuses with trisomy 13 in this series. Major (structural) malformations were seen in 23 cases (82.1%), whereas minor anomalies were detected on sonography in 16 cases (57.1%). Although in 2 fetuses 1 minor anomaly was the only sonographic sign of trisomy 13, other cases with minor anomalies (87.5% [n = 14]) were multiplex malformations, in which combinations of major and minor anomalies were detected on sonography. The most frequently seen structural abnormalities were central nervous system and facial anomalies (64.3% [n = 18]). Among central nervous system anomalies, ventriculomegaly and holoprosencephaly were seen most frequently. Cardiovascular anomalies were detected in 53.6% (n = 15) of the fetuses with trisomy 13. This high frequency underlines the importance of echocardiography in diagnosing this aneuploidy. Among minor anomalies, increased nuchal translucency (21.4%) and echogenic bowel (17.9%) were the most common findings. CONCLUSIONS: Second-trimester sonographic examination is capable of showing anomalies that are characteristic of trisomy 13; thus, the scan can indicate whether fetal karyotyping is advisable. Incorporation of careful assessment of the fetal cardiovascular system by sonography certainly increases the detection rate of trisomy 13.     

Is Fetal Anatomic Assessment on Follow‐up Antepartum Sonograms Clinically Useful?

OBJECTIVE: The purpose of this study was to evaluate the clinical usefulness of a fetal anatomic survey on follow-up antepartum sonograms. METHODS: A retrospective follow-up study was conducted at a low-risk maternity clinic from July 1, 2005, to June 30, 2006. Eligible women had at least 1 prior sonographic examination beyond 18 weeks' gestation with a complete and normal fetal anatomic assessment and at least 1 follow-up sonogram. Full fetal anatomic surveys were performed on all follow-up sonograms regardless of the indication. Neonatal charts were reviewed for those patients whose follow-up sonograms revealed unanticipated fetal anomalies. Neonatal intervention was defined as surgical or medical therapy or arranged subspecialty follow-up specifically for the suspected fetal anomaly. RESULTS: Of a total of 4269 sonographic examinations performed, 437 (10.2%) were follow-up studies. Of these, 101 (23.1%) were excluded because the initial sonogram revealed a suspected fetal anomaly, and 42 (9.8%) were excluded for other reasons. Of the remaining 294 women, 21 (7.1%) had an unanticipated fetal anomaly, most often renal pyelectasis. Compared with follow-up sonography for other reasons, repeated sonography for fetal growth evaluation yielded a higher incidence of unexpected fetal anomalies: 15 (12.3%) of 122 versus 6 (3.5%) of 172 (P = .01). When compared with the neonates in the nongrowth indications group, those neonates whose mothers had sonographic examinations for fetal growth had a higher rate of neonatal interventions: 6 (40.0%) of 15 versus 0 (0%) of 6 (P = .04). CONCLUSIONS: A fetal anatomic survey on follow-up sonograms may identify unanticipated fetal anomalies, especially when the indication is for fetal growth.     

Correlation between fetal gastric size and amniotic fluid volume

PURPOSE: Since abnormal conditions of the fetal digestive tract may alter both amniotic fluid volume and fetal gastric volume, we sought to determine whether amniotic fluid volume is correlated with fetal gastric volume in normal pregnancy. METHODS: A total of 280 fetal gastric size measurements were made prospectively from routine sonographic examinations of women with normal singleton pregnancies between 16 and 42 weeks of gestation. The fetal stomach was defined as the largest area including the pyloric site on transverse or oblique real-time sonographic scans. Gastric volume was calculated according to the formula for a prolate ellipsoid. The amniotic fluid index (AFI) was used for the evaluation of amniotic fluid volume. RESULTS: Both fetal gastric volume and AFI were significantly correlated with gestational age (R2= 0.422 and R2= 0.128, respectively). Only a weak correlation was found between gastric volume and AFI (R2= 0.036, p <0.001). On multivariate linear regression analysis adjusting for gestational age and fetal biometric measurements, gastric volume was not an independent and significant predictor of AFI. CONCLUSIONS: Although sonographically determined fetal gastric volume measurements appear to be useful in the assessment of fetal digestive tract anomalies, fetal gastric volume has no clinically significant effect on the amniotic fluid volume in normal pregnancy.     

Polyhydramnios and fetal intrauterine growth restriction: ominous combination.

The purpose of this study was to evaluate the significance of polyhydramnios combined with intrauterine growth restriction. During a 6 year period, 39 fetuses were identified by prenatal sonography as having both polyhydramnios and intrauterine growth restriction. Polyhydramnios was defined as a four-quadrant amniotic fluid index of 24 or greater (mean 30.5, range 24 to 40). Intrauterine growth restriction was defined as estimated fetal weight less than the tenth percentile (Hadlock standards). The mean birth weight was 2213 g. Major anomalies were present postnatally in 92% (36 of 39) of fetuses. Among nine fetuses without sonographically detectable anomalies prenatally, six (67%) proved to have one or more anomalies at birth. Chromosome abnormalities were present in 38% (15 cases) including 10 fetuses with trisomy 18 and one with trisomy 13. The overall mortality rate was 59%. The combination of polyhydramnios and intrauterine growth restriction is ominous. The majority of fetuses have major anomalies or chromosome abnormalities, or both, even when other sonographic abnormalities are absent. Chromosome analysis and detailed fetal evaluation should be offered when polyhydramnios and intrauterine growth restriction are identified prenatally.     

Transvaginal power Doppler findings in laparoscopically proven acute pelvic inflammatory disease.

OBJECTIVES: To evaluate the usefulness of power Doppler transvaginal sonography (TVS) in the diagnosis of pelvic inflammatory disease (PID) and to assess the diagnostic reliability of specific sonographic findings. POPULATION: The study population consisted of 30 women admitted for suspected acute PID. The reference group consisted of 20 women with proven hydrosalpinx formation. METHODS: Both conventional TVS and power Doppler TVS were performed. All patients with suspected acute PID underwent laparoscopy in order to confirm the diagnosis. Sonographic criteria described earlier were used for the diagnosis of acute PID. Power Doppler was used to assess the vascularity of any adnexal mass. RESULTS: Laparoscopy confirmed the diagnosis of PID in 20 (67%) of the 30 women with clinically suspected acute PID. Specific TVS findings, including wall thickness > 5 mm, cog-wheel sign, incomplete septa, and the presence of cul-de-sac fluid, discriminated women with acute PID from the control women with hydrosalpinx formation. Power Doppler TVS revealed hyperemia in all women with acute PID, but in only two women with hydrosalpinx (P = 0.01). Pulsatility indices were significantly lower in the acute PID group than in the control group (pulsatility index 0.84 +/- 0.04 vs. 1.50 +/- 0.10; P < 0.01). CONCLUSION: Power Doppler TVS was 100% sensitive and 80% specific in the diagnosis of PID (overall accuracy 93%). Specific sonographic landmark findings and power Doppler findings augment the clinical diagnosis of PID and allow simple classification of the severity of the disease.     

Correlation of prenatal sonographic diagnosis and morphologic findings of fetal autopsy in fetuses with trisomy 21.

OBJECTIVE: The purpose of this study was to compare the prenatal sonographic and postmortem pathologic findings of fetuses with trisomy 21. METHODS: Among 22,150 fetal chromosome analyses, trisomy 21 was diagnosed in 207 fetuses between 1990 and 2004. Findings of second-trimester sonography and fetal autopsy were compared by organ system, and their correlation was assigned to 1 of 3 categories. RESULTS: In total, 83.1% of the 184 fetuses that constituted the final study group had 1 or more abnormal structural findings at postabortion pathologic examination, whereas in 16.9% of the cases, fetal pathologic examination did not reveal any defects in fetal anatomy. Among major structural defects, the agreement between sonographic and autopsy findings was greater than 60% of all abnormalities of these systems: central nervous system (65.4%), heart (67.4%), fetal hydrops (100%), and cystic hygroma (93.3%), whereas the concordance rate was lower in these organ systems: abdominal abnormalities (46.2%), renal anomalies (50%), facial abnormalities (1.2%), and extremities (4.4%). The rate of additional major findings at autopsy was 34.2%. These mainly involved 3 organ systems: heart, head, and abdominal anomalies. Some sonographic findings (n = 16) were not verified at autopsy. The concordances between sonographic and autopsy findings regarding soft markers were considerably high in these markers: increased nuchal fold thickness (72%), short femur/humerus (75%), and pyelectasis (51.9%). CONCLUSIONS: Examining the correlation between sonography and pathologic findings may indicate possible directions of further development in sonographic screening for trisomy 21. In addition to obstetricians, pediatricians, and geneticists, specialized perinatal pathologists have an important role in the multidisciplinary management of prenatally diagnosed fetal malformations.     

Sonographic detection of trisomy 13 in the first and second trimesters of pregnancy.

OBJECTIVE: The purpose of this study was to examine sonographic findings in fetuses with trisomy 13. METHODS: A retrospective review of the cytogenetic laboratory databases at 6 tertiary referral centers identified all cases of trisomy 13. The prenatal sonographic studies in fetuses of less than 22 weeks' gestation, done before invasive testing for karyotype, were reviewed for anatomic and biometric findings. We defined abnormal fetal biometric findings as a biometric measurement (biparietal diameter, abdominal circumference, or femur length) below the fifth percentile in the second trimester. RESULTS: There were 8 cases of trisomy 13 found in the first trimester and 54 cases found in the second trimester, a total of 62 in all. In the first trimester, 6 of 8 had an anomaly identified (4 with cystic hygroma). In the second trimester, 49 of 54 were identified by sonography; 45 had an anomaly, and 4 had an abnormal fetal biometric measurement without an anomaly. The 5 missed diagnoses had early gestational age (<17 weeks; n = 3) or an inadequate survey secondary to poor visualization. Overall, 22 of 54 fetuses with trisomy 13 had an abnormal biometric measurement. The most common anomalies detected in the second trimester were heart defects (n = 34), central nervous system anomalies (n = 30), facial clefts (n = 19), abnormal hands (n = 13), and genitourinary anomalies (n = 9). CONCLUSIONS: Targeted sonography identified abnormal fetal anatomy or abnormal biometric measurements in 95% of fetuses with trisomy 13 in the second trimester after 17 weeks' gestation. A biometric measurement below the fifth percentile was noted in nearly half of cases in the second trimester.     

Early detection of embryonic malformations by transvaginal and color Doppler sonography.

A total of 834 women with uneventful pregnancies were followed prospectively until the 15th week of gestation by TVS to screen for early embryonic malformations. Twenty-eight embryonic anomalies were detected in this series (3.3%). The median gestational age at diagnosis was 11 (range, 8 to 15) weeks. Two neural tube defects were missed by early TVS screening. Two suspected abdominal wall defects were not confirmed by repeat mid-second trimester abdominal sonography representing 6.7% of all fetal malformations evident by 24 weeks of gestation. The sensitivity and specificity of TVS screening for fetal malformations in this series were 93.3 and 99.7%, respectively. In addition, the role of TCDU also was investigated in these 28 abnormal embryos. TCDU proved to be of limited value as it was useful only for evaluating those embryonic malformations with vascular involvement. In such cases, the diagnosis was greatly enhanced with this technique. Two previously undetected single umbilical arteries were also diagnosed by TCDU as well. This series included 11 aneuploid embryos (44%), most of them among the embryos with focal or generalized edema. This study demonstrates that screening for early embryonic malformations is feasible using TVS techniques, but a repeat mid-second trimester abdominal sonogram still is recommended.     

Prenatal detection of fetal trisomy 18 through abnormal sonographic features.

OBJECTIVE: To describe the prenatal detection of fetal trisomy 18 through abnormal sonographic features and to determine the sensitivity of sonographically detecting fetuses with trisomy 18. METHODS: All genetic and cytogenetic records of fetuses with trisomy 18 were reviewed retrospectively (1992-2002). From these, singleton fetuses who had prenatal sonography at our unit were identified. The maximal numbers of individual abnormalities from 1 sonographic examination (not limited to type of organ system) were recorded. Each abnormality was classified as major, minor, or "other," and each organ system was classified as abnormal only once, regardless of the number of individual abnormalities identified in that system. The sensitivity of sonography in detecting abnormalities of trisomy 18 was determined. RESULTS: Of 38 fetuses identified with trisomy 18, all had 4 or more prenatally detected sonographic abnormalities (sensitivity of sonographic detection of fetuses with trisomy 18, 100%). The median number of abnormalities per examination was 8 (range, 4-19). Sonographically detected major abnormalities were cardiac (84%; n = 32), central nervous system (87%; n = 33), gastrointestinal (26%; n = 10), and genitourinary (16%; n = 6). Sonographically detected minor abnormalities were short ear length below the 10th percentile for gestational age (96%; n = 26/27), upper extremities and hands (95%; n = 36), lower extremities and feet (63%; n = 24), and face (53%; n = 20). Fifty percent (19 of 38) had choroid plexus cysts identified, but this was never an isolated finding. CONCLUSIONS: In experienced hands, the sensitivity of detecting fetal trisomy 18 on prenatal sonography is 100%, and all cases will have multiple anomalies visualized.