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Obesity is an epidemic in the United States, especially among the pregnant population. Obesity is responsible for an increase in fetal anomalies and adverse outcome of both mother and fetus. Due to difficulty in penetrating to the depth of the uterus, the ultrasound image in obese patients is inadequate, fuzzy, and high in artifacts. Hence, obese patients often require multiple scans as well as special scanning techniques just to get borderline image quality. These techniques and the data regarding quality and frequency of scans for the obese pregnant population are discussed in this paper., (© 2013 Elsevier Inc. All rights reserved.)

Purpose: To examine whether the third-trimester fetus can be assessed sonographically using 3-dimensional (3D) volume data sets., Methods: Twenty-seven consecutive third-trimester fetuses were evaluated. Fetuses were scanned using 2-dimensional (2D) imaging followed by 5 3D volume acquisitions. The initial scan was interpreted and reported based on the 2D images. The 3D volume data sets were independently reviewed offline several weeks later by 2 sonologists. Parameters evaluated included fetal presentation, placental location, amniotic fluid volume, fetal biometry including a calculation of estimated fetal weight, and major fetal anatomic structures. The result of the interpretation via 3D reconstruction of the volume from each of the 2 sonologists was compared with the original 2D sonography report., Results: Fetal presentation, amniotic fluid volume, and placental location with respect to the cervix were correctly identified 100% of the time by each sonologist. The estimated fetal weight was within 10% of the 2D estimate 89% (95% CI, 0.71-0.98) of the time for sonologist A and 96% (95% CI, 0.81-0.99) of the time for sonologist B. The majority of major anatomic landmarks were adequately seen by both sonologists., Conclusion: Offline review of 3D volume data sets is a reliable method for determining fetal presentation, amniotic fluid volume, placental location, and estimating fetal weight in the third trimester.

We present a case of Fryns' syndrome diagnosed prenatally using three-dimensional (3D) ultrasonography and magnetic resonance imaging (MRI). A cleft of the soft palate was diagnosed using 3D thick-slice ultrasonography. Other sonographic findings included a right diaphragmatic hernia, enlarged echogenic kidneys and severe polyhydramnios. The detection of the cleft palate was instrumental in suggesting the diagnosis of Fryns' syndrome in a fetus which also had a diaphragmatic hernia. These findings were also demonstrated with prenatal MRI. The technique of imaging the soft palate en face using a thick-slice technique is presented., (Copyright 2006 ISUOG)

Frontonasal malformation includes a spectrum of anomalies involving the eyes, nose, lips, forehead and brain. We present a case in which a fetal labial cleft was initially identified using traditional two-dimensional sonography. Three-dimensional sonography with multiplanar reconstruction and surface-rendering were essential to establish the diagnosis of frontonasal malformation with severe nasal hypoplasia and unilateral complete cleft lip/palate.

We sought to evaluate whether the expected fetal femur length, based on biparietal diameter, varies in second-trimester fetuses with respect to maternal race. The study population was composed of all fetuses scanned from 15 to 20 completed weeks' gestation during a 2-month period (June to August 1998). Maternal race was documented at the time of the ultrasonographic examination. Biparietal diameter and femur length were prospectively documented. The variance from the expected femur length, given the biparietal diameter, was calculated, and the mean variations were compared according to maternal race. The study subgroups were composed of the fetuses of 39 Asian mothers, 31 black mothers, and the first 100 white mothers. The mean values of the variance from the expected fetal femur length by biparietal diameter +/- 1 SD for the various racial groups were as follows: fetuses of Asian mothers, -0.66 +/- 1.64 mm; fetuses of black mothers, 0.88 +/- 1.57 mm; and fetuses of white mothers, 0.13 +/- 1.66 mm (P = .0007). To isolate the differences among the 3 racial groups, the mean values of the variance from the expected femur length by biparietal diameter for the fetuses of Asian and black mothers were compared with the mean value for the fetuses of white mothers (Asian versus white mothers, P = .014; black versus white mothers, P = .026). A significant difference in the mean variance from the expected femur length by biparietal diameter was identified among the fetuses of women in the second trimester with respect to racial group. Less-than-expected femur lengths were noted among the fetuses of Asian mothers, and greater-than-expected femur lengths were noted among the fetuses of black mothers, compared with the femurs of fetuses of white mothers. The implications for the use of fetal femur length as a component of the genetic sonogram in patients of various races require further study.

Our objective was to determine the clinical significance of isolated polydactyly identified on prenatal sonogram. All patients with sonographically detected isolated polydactyly scanned over an 11-year period were identified from our database. All patients underwent detailed surveys, and follow-up was obtained by review of the medical records and telephone conversations with parents and referring physicians. Thirteen patients with isolated polydactyly were identified. Follow-up was available in 12 patients. Indications for referral included advanced maternal age (2), second-opinion polydactyly (4), family history of polydactyly (1), uncertain dates (5), and growth (1). The gestational ages at the times of sonographic diagnosis ranged from 17.5 to 34 weeks with all but one case being identified before 23 weeks. Prenatal identification included polydactyly of the upper limb (8), lower limb (4), and both upper and lower limbs (1). Postaxial polydactyly was seen in 12 patients and preaxial in one. Polydactyly was confirmed in all 12 cases in which follow-up was available. Karyotypes were normal in all five fetuses in which amniocentesis was performed. Ten of 12 fetuses were born alive, one died in utero at 34 weeks as a complication of severe pre-eclampsia and one died at term as a result of a cord accident. No surviving neonate had any other identifiable malformation or suspected karyotypic abnormality. In conclusion isolated polydactyly identified by prenatal sonography is associated with good perinatal outcome., (Copyright 2000 John Wiley & Sons, Ltd.)

A case of fetal Pfeiffer's syndrome is presented, showing the contribution of three dimensional (3D) sonography in the diagnosis of craniosynostosis--a major feature of this syndrome.

Objectives: The purpose of this study was to evaluate the clinical significance of hyperextension of the fetal head detected by ultrasound prior to the onset of labour., Methods: Over a 10-year period, we retrospectively identified all fetuses who had hyperextension of the fetal head reported on antenatal ultrasound. Hyperextension referred to persistence of the cervical spine in extreme extension, with an extension angle of at least 150 degrees persisting for the duration of the scan. Follow-up information was obtained from Hospital medical records and obstetrical care providers., Results: Follow-up was obtained on 57 of the 65 fetuses (87.7%) identified over the study period. Ten of the 57 fetuses had normal structural fetal surveys and had sonographically identified resolution prior to delivery. All 10 patients delivered at term and had newborns with normal neonatal courses. Twenty-six of 57 fetuses had no sonographic findings other than persistent hyperextension, and 19 of these 26 fetuses (73%) had normal neonatal courses. Twenty-one of 57 fetuses (37%) had structural anomalies sonographically identified in addition to hyperextension of the fetal head. All 21 of these pregnancies ended in either termination or fetal or neonatal demize., Conclusions: Although resolution of isolated hyperextension of the fetal head is associated with a normal neonatal outcome, persistent isolated hyperextension of the fetal head can be associated with either a normal or an abnormal neonatal outcome. Fetuses with hyperextended heads and antenatally diagnosed structural anomalies have dismal outcomes. The identification of a fetus with hyperextension of the fetal head should prompt a detailed search for structural abnormalities.

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., (Copyright 2000 John Wiley & Sons, Ltd.)

The prenatal sonographic findings in two children with Aicardi syndrome are reported., (Copyright 2000 John Wiley & Sons, Ltd.)

Purpose: We studied whether a 10-MHz transvaginal transducer improves the diagnostic certainty that a small intrauterine fluid collection is a true gestational sac., Methods: Over a 6-week period, women who presented with a positive pregnancy test and a fluid collection (devoid of any characteristics such as yolk sac or fetal pole) in the uterus seen with a standard 6-7-MHz transvaginal transducer were entered in the study. The patients were immediately rescanned with a 10-MHz transvaginal probe, and characteristics of the fluid collection using this probe were noted. Specifically, the visualization of a yolk sac or the intradecidual or double decidual sign was considered an objective improvement in the certainty that the fluid collection was a gestational sac., Results: Twelve patients presented with a positive pregnancy test and a fluid collection in the uterus seen with a 6-7-MHz probe. Eight of these fluid collections were smaller than 1 cm in mean diameter, and all 8 of these patients had an objective improvement in the diagnosis of an intrauterine pregnancy using the 10-MHz probe. The other 4 patients had fluid collection 1-2 cm in mean diameter seen at 6-7 MHz. The 10-MHz probe improved the diagnostic confidence in 2 of these 4 patients., Conclusions: In patients with early pregnancies who have questionable gestational sacs on sonography with standard 6-7-MHz transducers, the 10-MHz probe improves the diagnostic confidence of the presence of an intrauterine gestational sac., (Copyright 1999 John Wiley & Sons, Inc.)

We sought to evaluate the accuracy of the genetic sonogram scoring index in detecting Down syndrome fetuses in a high-risk population. Women referred for genetic sonogram scoring index based on increased risk for aneuploidy were prospectively evaluated. Each fetus was assigned a score based on our previously published genetic sonogram scoring index. A score of 1 or greater was an indication for karyotype determination. Of 1076 patients (1118 fetuses) in the study group, follow-up data were available for 1030 (92%), eight of whom had Down syndrome (prevalence 0.8%). Three fetuses with Down syndrome had a genetic sonogram scoring index of 0, and for one of these the mother was 42 years old. One affected fetus had a score of 1 and the other four had scores of 2 or greater. Using a genetic sonogram scoring index of 1 or greater (age not considered), five of eight fetuses with Down syndrome (62.5%) were identified, as well as 150 of 1030 (14.6%) of normals. Down syndrome was undetected in three fetuses of 1030 (1 in 343) or 0.29%. In addition, when all women 40 years old or older underwent karyotype testing regardless of their sonographic findings, six of eight Down syndrome fetuses were identified (75%), as well as 271 of 1030 (26.3%) of normals. The number of cases of Down syndrome not detected was two in 1030 (1 in 515) or 0.19%. In conclusion, the genetic sonogram scoring index was used to identify approximately 75% of fetuses with Down syndrome, with amniocentesis being recommended in 26.7% of a high-risk population.

Objective: To determine whether the iliac angle of second-trimester fetuses is a useful sonographic marker for the detection of fetuses with Down's syndrome., Methods: We prospectively measured the iliac angle for all fetuses karyotyped over a 17-month period. A transverse view of the upper fetal pelvis was obtained at the time of amniocentesis and, by means of a protractor, the angle between the two iliac bones was measured. The angles of all those fetuses with Down's syndrome and the first 500 fetuses with normal karyotypes were compared, as was gestational age and maternal age., Results: Nineteen fetuses with Down's syndrome and 1167 fetuses with normal karyotypes underwent genetic amniocentesis over the study period. The mean gestational age of the fetuses with Down's syndrome was 16.6 weeks (+/- 1.9 weeks), and for the controls, 16.1 weeks (+/- 1.4 weeks) (p = 0.3). The mean maternal ages were 34.7 years (+/- 4.8 years) and 35.4 years (+/- 4.1 years) for those pregnancies with Down's syndrome and with normal karyotypes, respectively (p = 0.5). The mean iliac angle was 80.1 degrees (+/- 19.7 degrees) for those fetuses with Down's syndrome, and 63.1 degrees (+/- 20.3 degrees) for those fetuses with normal karyotypes (p = 0.0004). The iliac angle was at least 90 degrees in 36.8% (seven of 19 fetuses) with Down's syndrome and in 12.8% (64 of 500 fetuses) with normal karyotypes (p = 0.003)., Conclusion: Fetuses with Down's syndrome have a significantly larger iliac angle than fetuses with normal karyotypes. Use of an iliac angle cut-off point of 90 degrees would identify over one-third of second-trimester fetuses with Down's syndrome. However, because of the high false-positive rate (12.8%), the iliac angle is not useful in a high-risk population as a screening test when used in isolation.

Objective: Our purpose was to determine the significance of finding an isolated clubfoot on a prenatal sonogram., Study Design: All fetuses found to have an isolated congenital clubfoot over a 9-year period were retrospectively identified. Fetuses with associated anomalies were excluded. Review of medical records for obstetric and neonatal outcome and pathologic and cytogenic results were tabulated., Results: Eighty-seven fetuses were identified from our database as having isolated clubfoot on prenatal ultrasonography, with complete follow-up available for 68 fetuses. Sixty of the 68 fetuses were confirmed as having clubfoot after delivery (false-positive rate = 11.8%). The male/female ratio was 2:1. Four fetuses (5.9%) had abnormal karyotypes: 47,XXY, 47,XXX, trisomy 18, and trisomy 21. Nine fetuses had hip or other limb abnormalities noted after birth. Other anomalies not detected until delivery included a unilateral undescended testis, ventriculoseptal defects (n = 2), hypospadias (n = 2), early renal dysplasia, mild posterior urethral valves, and a two-vessel cord. Five of the 68 patients (including those with aneuploidy) had pregnancy terminations. Eleven patients were delivered preterm., Conclusion: Karyotypic evaluation is recommended when isolated clubfoot is identified on prenatal sonogram because other subtle associated malformations may not be detected ultrasonographically in the early second trimester.

This case report describes a fetus with a large intra-abdominal, complex, vascular mass, displacing the normal intra-abdominal organs due to its large size. Extension to the presacral area was also identified, facilitating the diagnosis of a sacrococcygeal teratoma. Because of its highly mature nature, this was considered a fetus in fetu which was totally intra-abdominal.

Purpose: We evaluated the outcome of fetuses with prenatally diagnosed undescended testes at 35 weeks or more of gestation., Methods: We identified the fetuses in our database in whom undescended testes were identified sonographically in the last month of pregnancy and for whom outcome information could be obtained. Associated sonographic abnormalities were tabulated from the original reports. Outcomes were obtained through reviews of the pediatric medical records and pathology reports., Results: Six fetuses in 5 patients (1 had twins) were identified as having an empty scrotum at 35 weeks or later. In 3 fetuses, this finding was the only prenatal sonographic abnormality. One of these fetuses had isolated undescended testes at birth; the twins were found at birth to be females with congenital adrenal hyperplasia and severe masculinization of the genitals. The other 3 fetuses had other malformations seen prenatally, including omphalocele and macroglossia (Beckwith-Wiedemann syndrome), a left diaphragmatic hernia, and multiple congenital abnormalities., Conclusions: Although the finding of undescended testes in late gestation may be noted in an otherwise normal fetus, it may also be associated with a potential risk for perinatal problems ranging from severe multiple congenital abnormalities to incorrect sex assignment due to masculinization of female genitalia.

Our objective was to evaluate the significance of an echogenic intracardiac focus in a mixed population of fetuses at high and low risk for aneuploidy. Over a 1 year period, we prospectively identified all fetuses with an echogenic intracardiac focus seen during prenatal sonography. A detailed structural evaluation was performed on each fetus as permitted by gestational age. The location and number of foci were tabulated prospectively, as were associated abnormalities. Follow-up was obtained by review of the medical record. Of the 290 fetuses who had an echogenic intracardiac focus, 14 of them were aneuploid (4.8%). Of the 290 mothers, 125 women were aged 35 years or older and 165 women were younger than 35 years old. Among the 125 fetuses born to women 35 years or older, eight were aneuploid fetuses (6.4%), while among the 165 fetuses of younger mothers, six were aneuploid fetuses (3.6%) (rate ratio = 1.8; 95% confidence interval [extremes] = 0.6, 4.9). Only one of the 14 aneuploid fetuses had an echogenic intracardiac focus as the only sonographic finding, and this occurred in a woman aged 41 years. The majority of the echogenic intracardiac foci (87.6%) were located in the left ventricle, while 4.8% of the foci were right-sided and 7.6% were bilateral. Among the 14 aneuploid fetuses, 14% had bilateral echogenic intracardiac foci and 7% had right-sided foci. Among the euploid fetuses, 7.3% had bilateral echogenic intracardiac foci and 4.7% had right-sided foci. In conclusion, we have shown that the presence of an echogenic intracardiac focus does raise the risk that the fetus has a chromosomal abnormality, most commonly Down syndrome, although all but one aneuploid fetus in our study had other sonographic findings.

Sonographic markers for Down's syndrome have been useful in the identification of affected fetuses. In this study, we evaluated the accuracy of an expanded scoring index that included recently described sonographic markers as well as maternal age to optimize identification of fetuses with Down's syndrome. Over a 27-month period, we performed 4075 genetic amniocenteses for advanced maternal age or an abnormal triple panel. Prior to each amniocentesis, a complete sonographic assessment of the fetus was performed including a structural survey and fetal biometry. Each patient was assigned a score based on the sonographic markers in a previously reported scoring system, modified by the addition of an echogenic intracardiac focus. The sonographic scoring system was then combined with the assignment of additional points based on maternal age. Karyotypic results were obtained subsequent to the scans, and Down's syndrome fetuses and a control group of normal fetuses were compared. Fifty-three fetuses with Down's syndrome were identified by karyotype and compared to a control group of 177 normal fetuses. A score of > or = 2 as a criterion for a positive test resulted in the identification of 75.4% of fetuses with Down's syndrome, with a 5.7% false-positive rate. A score of > or = 1 increased the sensitivity to 83.0%, with a false-positive rate of 17.5%. The age-adjusted modification resulted in the identification of 86.8% of fetuses with Down's syndrome, with a false-positive rate of 27.1%. It is for the individual patient and her practitioner to weigh the risks and benefits in selecting her options for prenatal diagnosis.

Purpose: The combination of in utero bladder distension and bilateral hydroureteronephrosis in male fetuses may result from a number of pathological processes. The prenatal and postnatal treatment of patients with an enlarged bladder is dictated by the specific etiology leading to these changes. We propose specific ultrasonographic criteria for differentiating between obstructive and nonobstructive etiologies in these fetuses., Materials and Methods: We reviewed the medical records and prenatal imaging studies of 18 cases of marked in utero bladder distension in which a diagnosis of posterior urethral valves, the megacystis-megaureter association or the prune-belly syndrome was confirmed postnatally. Amniotic fluid volume and renal echogenicity were assessed before knowledge of the specific diagnosis. Oligohydramnios was graded as mild, moderate or severe. Increased renal echogenicity was defined as greater echogenicity of the renal cortex and/or medulla than of adjacent liver tissue. Postnatal imaging, clinical course and outcome were also reviewed., Results: The study included 15 cases with adequate followup, including 8 in which a diagnosis of posterior urethral valves was confirmed postnatally. Nonobstructive etiologies included the megacystis-megaureter association in 6 cases and the prune-belly syndrome in 1. Seven of the 8 patients with posterior urethral valves had moderate to severe oligohydramnios, whereas all but 1 with a nonobstructive etiology had normal amniotic fluid. Seven of the 8 cases with posterior urethral valves had a marked bilateral increase in renal echogenicity, while none of the nonobstructive cases had this finding., Conclusions: Increased renal echogenicity and oligohydramnios in the setting of bladder distension are highly predictive (87%) of an obstructive etiology. This finding is important in the prenatal counseling and treatment of boys with bilateral hydronephrosis and marked bladder dilatation.

We describe three cases of unilateral pulmonary agenesis as an etiological basis for a mediastinal shift in utero. This cause of mediastinal shift is easily overlooked in the differential diagnosis, which includes diaphragmatic hernia, adenomatoid cystic malformation, and sequestrations. The sonographic findings and obstetric outcome are presented.

We sought to determine the accuracy of sonographic diagnosis and perinatal outcome in pregnancies with maternal adnexal masses. All patients with a prenatal sonographic diagnosis of an adnexal mass measuring 4 cm or greater beyond 12 weeks of gestation were identified. Only masses associated with live fetuses, for which pathologic follow-up or direct visualization of the ovary was available at a single hospital, were included in the study. Sonographic evaluation of the pelvic mass was done prospectively at the time of the original scan and characterized on the basis of morphologic criteria. One hundred and twenty-five pregnant patients 21 to 47 years old with 131 lesions formed the study group. The pathologic diagnoses included 40 dermoids, 15 endometriomas, 14 cysts, 13 cystadenomas, nine tubal cysts, four fibroids, and one ovarian cancer. Six patients had complex pathologic lesions and five had unusual diagnoses. Twenty-four patients had normal ovaries on follow-up examination. Sonographically benign appearing lesions were seen in 89.3% of patients. Ninety-five percent of dermoids, 80% of endometriomas, and 71% of simple cysts were characterized correctly. Fourteen of the 131 lesions (10.7%) had sonographic characteristics suggestive of malignancy. One of these 14 patients (7%) had ovarian cancer. This represents a 0.8% malignancy rate among the total number of lesions. Twenty-four of the 125 patients (19%) underwent second trimester laparotomy at the discretion of their managing obstetricians, with no pregnancy losses. One patient had acute torsion of a dermoid at 39 weeks. Prenatal sonography can accurately characterize maternal adnexal lesions.

Objective: To determine whether measurements of the iliac wing angle on sonograms of the second-trimester fetus can be used to detect fetuses at increased risk for Down syndrome., Methods: All second-trimester Down syndrome fetuses karyotyped by amniocentesis over 5 years for whom adequate views of the iliac bones were available were reviewed retrospectively. The control group consisted of consecutive, normal second-trimester fetuses undergoing karyotyping during the same period. The angles between the iliac bones of the fetal pelves were measured on transverse sonograms, and the two groups were compared. A separate prospective evaluation of the ideal level for measurement of the iliac angle was made in two fetuses, one with and one without Down syndrome., Results: We evaluated 38 Down syndrome and 46 control fetuses. The mean iliac-angle measurements differed significantly for the Down syndrome fetuses as compared with normal control fetuses: 78.8 degrees +/- standard deviation (SD) 18.5 and 66.9 degrees +/- SD 13.9, respectively. An iliac angle of at least 90 degrees was measured in 14 (36.8%) Down syndrome fetuses and in two (4.3%) control fetuses, also a significant difference. In a prospective pilot evaluation of two fetuses, we measured the largest iliac angle at the most cephalad level of the iliac bones, and the smallest angle was measured at the most caudad level. The iliac angle measurements for the fetus with Down syndrome ranged from 55 degrees to 100 degrees; for the normal fetus, the range was 52 degrees to 80 degrees., Conclusion: Although there is considerable overlap, the average iliac angle for fetuses with Down syndrome is significantly larger than that of normal fetuses. The angle measurement varies widely in any given fetus and is dependent on the level of the image. A prospective study is needed to evaluate the best level of angle measurement for the detection of fetuses with Down syndrome.

In this study, we determined the outcome in cases of isolated nuchal lucency seen sonographically in the first trimester in fetuses without karyotypic abnormalities. We reviewed all cases of isolated localized fetal nuchal lucency (3 mm or greater) in 9 to 14 week fetuses over a 4 year period. Fetuses with additional sonographic abnormalities were excluded. The width of the nuchal lucency at initial sonogram as well as findings on subsequent scans were tabulated. Karyotypic, pathologic, and clinical follow-up data were obtained. Of 44 fetuses with an isolated, localized first trimester nuchal lucency, one was lost to follow-up and two were excluded owing to pregnancy termination without karyotype or pathologic analysis, thus resulting in 41 fetuses in our study group. Five fetuses (12%) had abnormal karyotypes. Twenty-seven of the remaining 36 fetuses had normal karyotypes, eight others showed no evidence of aneuploidy at birth, and one patient underwent spontaneous abortion prior to a karyotypic analysis. Among the 36 fetuses without evidence of aneuploidy, six had a poor outcome: two were spontaneous abortions, one was a therapeutic abortion of a fetus with hydrops and a pericardial effusion seen on fetopsy; one fetus died at birth of pulmonary hypoplasia associated with autosomal recessive polycystic kidney disease, and one fetus each had Noonan syndrome, and Joubert syndrome. In addition, three patients delivered their infants prematurely. Overall, 32 of 41 fetuses survived, and two (6%) were abnormal. Excluding premature infants, 27 were normally grown, term survivors. We conclude that other than having an increased risk for aneuploidy, fetuses with isolated nuchal lucency are also at risk for spontaneous miscarriage, premature delivery, and congenital anomalies unassociated with an abnormal karyotype.

The aim of this study was to determine the etiology, associated anomalies and outcome of fetuses with postural deformities and contractures of the upper extremities detected sonographically. Fifty-four fetuses with sonographically detected postural anomalies of the upper extremities were identified from our database. Sonographic findings and associated anomalies were tabulated on the basis of the original sonogram. Perinatal follow-up and/or karyotype were available in 52 cases from a review of the maternal and newborn medical records and pathology reports. Of the 52 fetuses with sonographically detected anomalies of the upper extremities, 44 (85%) were non-survivors and eight (15%) were survivors. Forty-three fetuses had associated sonographic abnormalities. Karyotyping performed in 44 cases revealed 26 cases (59%) of aneuploidy, with trisomy 18 accounting for 23/26 (88%). In the setting of a normal karyotype, a variety of genetic disorders were found, including syndromes involving the fetal dyskinesia/akinesia sequence. Disturbances in amniotic fluid occurred in 48% of the cases (24 fetuses with polyhydramnios and one with oligohydramnios). In conclusion, the sonographic detection of postural abnormalities of the upper extremities carries a guarded prognosis, with survival in 15% of fetuses and a high incidence of chromosomal defects.

We sought to determine whether there is an association between choroid plexus cysts identified in the second-trimester fetus and trisomy 21. Over a 7-year period, fetuses scanned between 14 and 22 weeks were prospectively evaluated for the presence of choroid plexus cysts. Follow-up on fetuses with choroid plexus cysts was obtained by review of the medical records. Over the same time period, the scans and reports of all fetuses with trisomy 21 detected in our laboratory by mid-trimester amniocentesis were reviewed. The prevalence of choroid plexus cysts in fetuses with and without trisomy 21 were compared by means of X2 analysis. A total of 473 fetuses with choroid plexus cysts were identified among 32,053 second-trimester fetuses. Sixteen fetuses were lost to follow-up, three had structural defects and normal karyotypes and 21 had abnormal karyotypes, two of which were trisomy 21. Other abnormal karyotypes included trisomy 18, unbalanced translocation and triploidy, previously reported elsewhere. The remaining 433 fetuses either had normal karyotypes or were normal newborns. The prevalence of choroid plexus cysts (excluding fetuses with trisomy 18) was 1.38% in our general population. During the study period, 143 fetuses with trisomy 21 were karyotyped in our laboratory, and two of these (1.40%) had choroid plexus cysts. Both had other sonographic abnormalities suggesting trisomy 21. The difference in prevalence of fetuses with choroid plexus cysts and trisomy 21 vs. those without trisomy 21 was not statistically significant (X2 = 0.98; relative risk (RR) = 1.02; 95% CI = 0.26, 4.03). We conclude that choroid plexus cysts occur with similar frequency in fetuses with trisomy 21 to that in fetuses from the general population. The finding of choroid plexus cysts should not be used to increase the patient's calculated risk of having a fetus with trisomy 21.

Purpose: To determine the effects of subchorionic hematoma size, gestational age, and maternal age on pregnancy outcome in patients with vaginal bleeding in the first trimester of pregnancy., Materials and Methods: A retrospective review was performed with ultrasound images obtained in 516 patients with vaginal bleeding, a live fetus, and a subchorionic hematoma in the first trimester. Hematoma size was graded according to the percentage of the chorionic sac circumference elevated by the hematoma. Patients were also classified according to gestational age and maternal age. Logistic regression analysis was used to determine the effect of each variable on pregnancy outcome., Results: The overall spontaneous abortion rate was 9.3% (48 of 516 patients). The rate nearly doubled when the separation was large (18.8%) compared with small and moderate hematomas (7.7% and 9.2%, respectively). A large separation was found to be associated with an almost three-fold increase in risk of spontaneous abortion. The spontaneous abortion rate was approximately twice as high for women aged 35 years or older versus younger women (13.8% and 7.3%, respectively) and for women with bleeding at 8 weeks gestation or less compared with those with bleeding at greater than 8 weeks gestation (13.7% vs 5.9%)., Conclusion: For women with a subchorionic hematoma that is sonographically identified, fetal outcome is dependent on size of the hematoma, maternal age, and gestational age.

Maternal phenylketonuria (PKU) is teratogenic and results in birth defects that include microcephaly, mental retardation, congenital heart disease, and intrauterine growth retardation. Treatment with a low phenylalanine diet can prevent or reduce the severity of the complications. Optimal benefit, however, requires frequent monitoring with fetal ultrasonography as a critical element. We have studied ultrasonography in 39 pregnancies enrolled in the Maternal PKU Collaborative Study and followed at our centre. First-trimester examinations in 24 pregnancies resulted in the discovery of non-viability in five. In each, this led to discontinuation of the difficult and expensive diet. Among the 33 pregnancies with second-trimester evaluation, congenital heart disease was identified in five. Two of these pregnancies were terminated. Microcephaly as determined by biparietal diameter (BPD) was identified in the second trimester in only one of nine fetuses who had microcephaly at birth. Among 20 pregnancies with third-trimester ultrasound, fetal microcephaly was identified by BPD in three of seven who had birth microcephaly. We conclude that fetal ultrasonography in maternal PKU is valuable during the first trimester in identifying non-viable pregnancies and determining gestational age and is also valuable during the second trimester in identifying congenital heart disease and perhaps other major anomalies, but not in identifying fetal microcephaly. Third-trimester ultrasound seems to be of limited usefulness.

Purpose: To determine whether agenesis of the corpus callosum can be diagnosed prenatally with standard ultrasonographic (US) evaluation before 22 weeks of gestation., Materials and Methods: Initial scans obtained on or before 22 weeks and follow-up scans obtained in the third trimester were selected from all cases of agenesis of the corpus callosum diagnosed prenatally at the authors' laboratory. Follow-up was attained by means of review of the medical records and included imaging, karyotype, and clinical outcome., Results: Among 15 fetuses with callosal agenesis confirmed by means of third-trimester scans, 10 had completely normal US scans at 16-22 weeks and five had other US abnormalities. Isolated callosal agenesis was identified in six children with normal development (except one with polydactyly). Among the others, four were developmentally delayed, three died, and two others had abnormal karyotype., Conclusion: Standard second-trimester US before 22 weeks of gestation may not show isolated callosal agenesis. Fetuses with this abnormality can have normal second-trimester scans and develop abnormal US findings in the third trimester.

Down syndrome (trisomy 21) is the most common chromosomal abnormality among liveborn infants in the United States, with an incidence of 1/700 to 1/1000 births. Its incidence rises with maternal age, thus prompting the current practice of offering genetic amniocentesis to women 35 years of age or older. However, even if every pregnant woman of advanced maternal age (> or = 35 years) were to undergo karyotyping, only 20% of fetuses with Down syndrome would be detected. Until approximately 10 years ago, karyotyping of the fetuses of older women was practically the only antenatal method of identifying any fetus with trisomy 21. In 1984, Cuckle and associates first reported the use of a low level of serum alpha-fetoprotein as a screening tool for identifying affected fetuses in younger women. Combining the criteria based on both maternal age and serum alpha-fetoprotein resulted in identifying 40% of fetuses with Down syndrome, as well as 6.8% of unaffected fetuses. Still, at least 60% of fetuses with Down syndrome remained undetected with these screening techniques. It is logical to expect that sonographic imaging of the second-trimester fetus itself would result in the optimal detection of the anatomical features of Down syndrome (Figure 1). To this end, many researchers have attempted to identify sonographic findings that would serve to detect fetuses likely to have Down syndrome. This review summarizes the characteristic sonographic findings associated with an increased risk of a fetus having trisomy 21.

We evaluated the significance of severe oligohydramnios, or anhydramnios, in the second and third trimesters, by determining the range of etiologies as well as the differences in fetal and neonatal outcome. All prenatal ultrasound results on pregnancies found to have severe oligohydramnios over a 7.5-year period at 13-42 weeks' gestation were retrospectively collected. Follow-up results were obtained from review of medical records, autopsies and pathology reports. A total of 250 singleton pregnancies met the criteria of having severe oligohydramnios. A bimodal distribution in gestational age at diagnosis was seen, with more cases diagnosed at 13-21 weeks and at 34-42 weeks. Fetal abnormalities were present in 50.7% of those diagnosed with severe oligohydramnios in the second trimester and in 22.1% of those in the third trimester. There were 10.2% and 85.3% survivors when severe oligohydramnios was diagnosed in the second and third trimesters, respectively. The rate of aneuploidy was at least 4.4% for the entire singleton population. A bimodal distribution of pregnancies presenting with severe oligohydramnios represents two different naturally occurring populations in terms of both etiology and prognosis.

Objective: To determine whether an echogenic intracardiac focus identified in the second-trimester fetus is related to an increased risk of Down syndrome., Methods: During a 10-month period, all women with singleton gestations who underwent second-trimester genetic amniocentesis for non-imaging indications were evaluated prospectively by prenatal sonography. The presence or absence of an echogenic intracardiac focus was noted. Karyotypic information was obtained on each fetus., Results: Among the 1334 patients in the study group, 66 fetuses (4.9%) had an echogenic intracardiac focus. Four of 22 fetuses (18%) with trisomy 21 had an echogenic intracardiac focus, compared with 62 (4.7%) of 1312 fetuses without Down syndrome who also had an echogenic intracardiac focus (P = .004). Sonographic identification of an echogenic intracardiac focus was associated with a fourfold increased risk of Down syndrome (risk ratio 4.3, 95% confidence interval 1.5-12.3). The overall prevalence of Down syndrome in our study population was 1.6%. The sensitivity, specificity, and positive predictive value for using the presence of an echogenic intracardiac focus to identify a fetus with Down syndrome was 18.2, 95.3, and 6.1%, respectively. Extrapolating to a lower risk population, the positive predictive value of an echogenic intracardiac focus for detecting Down syndrome in patients at an age-based risk of one in 250, one in 500, and one in 1000 was calculated to be 1.53, 0.77, and 0.39% respectively., Conclusion: Fetuses with an echogenic intracardiac focus have a significantly increased risk of Down syndrome. Although most fetuses with this finding are normal, patients carrying fetuses with an echogenic intracardiac focus should be counseled about the increased risk of trisomy 21.

Purpose: To determine the importance of intrahepatic calcifications seen sonographically in the fetus., Materials and Methods: The authors retrospectively reviewed sonograms obtained in fetuses scanned between 16 and 40 gestational weeks in whom intrahepatic calcifications were seen. The number and character of these calcifications were determined. Follow-up scans obtained in utero and after birth were also reviewed. Outcome was determined after birth., Results: Thirty-three fetuses had intrahepatic calcifications at 16-38 weeks gestation. Four of the 33 fetuses died, one of which had liver calcifications as the only sonographic finding. This fetus had cytomegalovirus and was the only fetus with increasing numbers of calcifications on follow-up scans. All fetuses with isolated liver calcifications had a normal postnatal outcome (96% survival rate for fetuses with isolated intrahepatic calcifications). Of eight fetuses with additional anomalies, five lived; only two were healthy newborns., Conclusion: The outcome in fetuses with isolated intrahepatic calcifications is usually excellent, although viral causes must be excluded if additional findings appear.

This pictorial essay illustrates abnormalities of the hands and feet that sonography depicts and describes their associations with chromosomal abnormalities, syndromes, and other pathology. Examination of the extremities, although not listed in the guidelines of the American Institute of Ultrasound in Medicine for standard obstetric sonography, is a critical adjunct to fetal imaging and is needed to diagnose many syndromes. Anomalies of the hands and feet may involve all limbs or be focal, involving a single distal ray. Although this essay focuses on defects of the hands and feet, these defects are often part of more global defects that include the rest of the limb as well. For this reason, anomalies of the limbs that relate primarily to defects of the hands and feet will also be demonstrated. Evaluation of the hands and feet is an important part of the structural survey of the fetus at all gestational ages, as it provides an adjunct to the diagnosis of many syndromes, including chromosomal abnormalities. Even isolated limb anomalies may be important to diagnose antenatally so that proper care can be instituted postnatally for families and their newborns.