Fetal 'space-suit' hydrops in the first trimester: differentiating risk for chromosome abnormalities by delineating characteristics of nuchal translucency.

Detecting first trimester fetuses with pan-body hydrops, giving the appearance of a 'space-suit,' is associated with a marked increased risk for chromosome abnormalities. In 30 consecutive fetuses prospectively characterized by space-suit hydrops, detected at or before 13.9 weeks' gestation, 26 (86.7%) were characterized by chromosome abnormalities. However, as opposed to the preponderance of autosome abnormalities among first-trimester fetuses with prominent nuchal translucencies, 15 of the 26 fetuses (57.7%) with abnormal complements were characterized by sex chromosome aneuploidies. Genetic counselling and consideration of invasive prenatal testing is warranted when space-suit hydrops is detected in the first trimester.

Prenatal diagnosis of genital anomalies.

OBJECTIVES: This is a report of five cases of abnormal fetal genitalia detected by routine prenatal ultrasound. METHODS: Retrospective review was conducted to identify all cases of abnormal fetal genitalia identified by routine obstetrical ultrasound at our institution in which postpartum follow-up was available. RESULTS: Five cases of prenatal sonographically diagnosed abnormal fetal genitalia were confirmed postnatally. The abnormalities include ambiguous genitalia, severe hypospadias with unilateral cryptorchidism, megalourethra, and concealed penis. In all cases, other anomalies were discovered during the prenatal ultrasound. CONCLUSIONS: Prenatal ultrasound may detect a variety of abnormalities of the fetal genitalia.

Remote real-time ultrasound interactive telediagnosis: putting it into practice.

Teleradiology, the practice of radiology over a distance via electronic transmission of radiologic images, has the potential to fundamentally alter the practice of radiology in the years to come. Different models for the practice of teleradiology include on-call reading, consultation and overreading, primary-reading teleradiology, and integration with picture archiving and communication system (PACS) and miniPACS. Remote real-time ultrasound telediagnosis represents a specialized subset of primary-reading teleradiology, specifically designed to involve the radiologist directly with sonographer in the performance of the ultrasound examination. This type of practice involves rapid transmission of patient demographics and captured still images and live transmission of the real-time video output of the ultrasound machine. When utilized properly real-time telediagnosis extends the high standards of tertiary center sonographic diagnosis out to community and rural sites.

Isolated fetal choroid plexus cysts and trisomy 18: a review and meta-analysis.

OBJECTIVE: Risk of trisomy 18 in a fetus with ultrasonographic diagnosis of choroid plexus cysts and no other anomalies is controversial. Using our data and current literature, we performed a meta-analysis and estimated the positive predictive value of isolated choroid plexus cysts for trisomy 18. STUDY DESIGN: Between Jan. 1, 1989, and Dec. 31, 1992, all women undergoing ultrasonographic examination at our institution were prospectively evaluated for fetal choroid plexus cysts and cytogenetic outcome. In addition, all reports dealing with fetal choroid plexus cysts obtained from MEDLINE (1983 through 1992) were assessed. Only prospective studies with > 10 cases of choroid plexus cysts were further evaluated to determine the total number of fetuses with choroid plexus cysts and otherwise normal sonograms. Frequency of aneuploidy was determined by analysis of our data and the included studies. To estimate the positive predictive value of choroid plexus cysts from trisomy 18, a theoretic 2 x 2 table was constructed with values available from the literature. RESULTS: Eighty fetuses with choroid plexus cysts were identified in our unit. Of 74 fetuses with isolated choroid plexus cysts, there were no cases of trisomy 18. Meta-analysis identified 2 cases of trisomy 18 among 748 fetuses with isolated cysts (1/374). To derive a positive predictive value of isolated choroid plexus cysts for trisomy 18, we reviewed the literature and found a total of 50 fetuses with trisomy 18 who underwent ultrasonographic examination in the midtrimester. There were 3 cases of isolated choroid plexus cysts, and 12 of 50 (24%) had otherwise normal ultrasonographic results. Using a midtrimester incidence of 1 in 2461 for trisomy 18 (Hsu LYF. In: Milunsky A, ed. Genetic disorders of the fetus. 3rd ed. Baltimore: Johns Hopkins University Press, 1992: 155-210; Hook et al. Am J Hum Genet 1989; 45:855-61) and a prenatal prevalence of 0.95% for choroid plexus cysts (based on a review of the literature), we obtained a positive predictive value of 1 in 390. CONCLUSION: On the basis of the risk for trisomy 18 obtained from our meta-analysis (1/374) and its close approximation to the estimated positive predictive value (1/390), our data do not support the routine offering of invasive prenatal cytogenetic testing in cases of isolated choroid plexus cysts.

Clinical course and outcome of fetuses with isolated cystic nuchal lesions and normal karyotypes detected in the first trimester.

OBJECTIVE: We assessed newborn outcome and infant development in cases of first-trimester fetal cystic nuchal lesion and normal karyotype. STUDY DESIGN: Information regarding newborn outcomes and infant growth and development was prospectively obtained from 32 consecutive pregnancies characterized by fetal cystic nuchal lesions detected in the first trimester (< or = 13.9 weeks' gestation) and normal karyotypes. RESULTS: Cystic nuchal lesions spontaneously resolved by the twentieth gestational week in 31 cases; all 31 infants had normal results at newborn examination and demonstrated normal growth and development at 12 months of age. Resolution did not occur in one case; prominent hygromas were repaired at birth with normal growth and development through 2 1/2 years of age. CONCLUSIONS: In most affected fetuses with normal karyotypes, spontaneous resolution will occur with favorable newborn and infant outcomes. However, patients should be counseled that resolution may not occur or that nonchromosome abnormalities may result in a less favorable outcome.

Severity of abnormality influences decision to terminate pregnancies affected with fetal neural tube defects.

We examined parental decision concerning pregnancy management in women having fetuses with neural tube defects (NTDs) to determine whether severity of defect or method of detection has an impact on the decision making process. Analysis of decisions by 50 women, whose pregnancies were affected by an isolated neural tube defect (NTD) and characterized by a singleton gestation at 24 gestational weeks or less with normal chromosomal complement (46,XX or 46,XY), were assessed. All 23 women carrying fetuses with anencephaly elected to terminate their pregnancies. Of the 27 women carrying fetuses with spina bifida, 21 (77.8%) elected to terminate their pregnancies and 6 (22.2%) elected to continue their pregnancies. Of the 6 pregnancies that were continued, 4 were initially detected by ultrasonography and 2 were ascertained by maternal serum alpha-fetoprotein screening; defects ranged from 2 to 14 vertebral bodies, and none of the defects were craniad to the T9 level. This is in comparison to 5 of the 21 spina bifida cases that were elective pregnancy terminations, which were characterized by fetal lesions craniad to the T9 level. Severity of NTD thus appears to influence the decision to continue or terminate an affected pregnancy.

Significance of septations in isolated fetal cystic hygroma detected in the first trimester.

Recent reports have indicated an increased risk for fetal chromosome abnormalities, especially autosomal trisomy, in fetuses with isolated cystic hygroma, or prominent nuchal membranes, detected by ultrasonography during the first trimester. However, these reports present contradictory information regarding the prognostic significance of septations within the cystic hygroma. We evaluated, in blind fashion, 55 consecutive cases of isolated fetal cystic hygroma detected at or before 13.9 weeks' gestation to determine the association between septations and fetal chromosome complement. Septations were associated (P < 0.05) with an increased risk for fetal chromosome abnormalities. However, the incidence of chromosome abnormalities was also increased (12.5 per cent) among cases not characterized by septations. Thus, we believe it prudent to offer invasive prenatal testing to all women found to be carrying fetuses with cystic hygroma, irrespective of the presence or absence of septations.

Predicting pregnancy survival from a single first trimester vaginal ultrasonogram.

This retrospective study evaluates early first trimester FHR, gestational SACD, and CRL measurements as means to predict ultimate pregnancy outcome. Outcomes of 274 pregnancies were monitored a single time by transvaginal ultrasonography with measurements recorded between 5.0 and 9.0 weeks' gestation. The measurements were then correlated with the pregnancy outcomes. FHR (P < 0.0001), gestational SACD (P = 0.0002), and CRL (P = 0.0059) each correlated positively with a successful pregnancy outcome. Measurements from a single transvaginal ultrasonogram can be used to predict a successful pregnancy outcome in the early first trimester.

Transvaginal chorionic villus sampling using transabdominal ultrasound guidance: a new technique for first-trimester prenatal diagnosis.

Transvaginal chorionic villus sampling (CVS) using concurrent transabdominal ultrasound guidance was performed in 20 women who desired CVS but could not be offered transcervical or transabdominal approaches because of uterine position and placental location. Satisfactory amounts of chorionic villi were obtained in all 20 cases with no maternal discomfort, an occurrence that contrasts with our experience in transvaginal CVS using endovaginal ultrasound guidance. We believe that transvaginal CVS using concurrent transabdominal ultrasound guidance warrants consideration as an alternative technique for first-trimester CVS in selected patients.

Predicting aneuploidy in fetuses with cardiac anomalies: significance of visceral situs and noncardiac anomalies.

To determine whether the risk of aneuploidy in fetuses with cardiac anomalies is affected by abnormal visceral situs or coexisting noncardiac anomalies (NCA), were reviewed 125 cases in which a structural cardiac anomaly was detected by prenatal sonography. Forty-three of the 125 fetuses (34%) had an abnormal karyotype (31 autosomal trisomies, 12 other). None of the 13 fetuses with abnormal visceral situs had an abnormal karyotype, whereas an abnormal karyotype was present in 43 of 112 with normal visceral situs (P < 0.01, Fisher's exact test). The karyotype was abnormal in 33 of 52 (63%) with coexisting NCA and in only 10 of 73 (14%) without coexisting NCA (P < 0.001, chi-square). Therefore, among fetuses with structural cardiac anomalies, abnormal visceral situs is strongly predictive (100% in our series) of normal karyotype, whereas the presence of coexisting NCA significantly increases the risk of aneuploidy. These findings can help guide recommendations concerning prenatal karyotyping.

High frequency of cytogenetic abnormalities in fetuses with cystic hygroma diagnosed in the first trimester.

OBJECTIVE: The purpose of this study was to evaluate the association between fetal cystic hygroma detected in the first trimester and fetal cytogenetic abnormalities. METHODS: Visualization of a prominent (2.5 mm or larger) anechoic or hypoechoic separation of the fetal skin line from the posterior body wall led to the diagnosis of fetal cystic hygroma; presence or absence of septations within the cystic hygroma was documented in each patient. Fetuses with additional structural defects were excluded from this study. All eligible women were offered prenatal cytogenetic studies (ie, chorionic villus sampling, amniocentesis). RESULTS: Cytogenetic studies were performed on all 32 affected fetuses. Fifteen of 32 fetuses (46.9%) had abnormal complements. Septations within the cystic hygroma were demonstrated in 18 fetuses; nine of these had abnormal karyotypes. Of the 12 women carrying fetuses with normal chromosome complements who elected to continue their pregnancies, 11 delivered infants with no evidence of cystic hygroma. CONCLUSIONS: Prenatal cytogenetic analysis should be offered to women with fetal cystic hygroma diagnosed in the first trimester. Normal outcome is likely in those showing no chromosome abnormalities.

Diagnostic efficacy of endovaginal color Doppler flow imaging in an ectopic pregnancy screening program.

The authors compared the diagnostic yield of endovaginal color and pulsed Doppler ultrasound (US) in conjunction with endovaginal sonography with that of endovaginal sonography alone in patients prescreened to be at increased risk for ectopic pregnancy. Pelvic structures were evaluated for overall vascularity and for the presence of characteristic pulsed Doppler US velocity waveforms. The diagnostic sensitivity of the initial endovaginal sonographic examination increased with the addition of color and pulsed Doppler US, from 71% to 87% for ectopic pregnancy, from 24% to 59% for failed intrauterine pregnancy, and from 90% to 99% for viable intrauterine pregnancy. Specificities for endovaginal sonography with color and pulsed Doppler US ranged from 99% to 100%. Use of endovaginal color and pulsed Doppler US increased the percentage of diagnostic initial sonographic examinations from 62% to 82%. The improved diagnostic sensitivity of endovaginal color Doppler US for ectopic pregnancy may ultimately result in earlier treatment, with reduced morbidity and mortality.

Transvaginal chorionic villus sampling using transabdominal ultrasound guidance.

Transvaginal chorionic villus sampling (CVS) using concurrent transabdominal ultrasound guidance was performed in six women who desired CVS but could not be offered transcervical or transabdominal approaches because of uterine position and placental location. Satisfactory amounts of chorionic villi were obtained in all six cases with no maternal discomfort, an occurrence that contrasts with our experience in transvaginal CVS using endovaginal ultrasound guidance. We believe that transvaginal CVS using concurrent transabdominal ultrasound guidance warrants consideration as an alternative technique for first-trimester CVS in selected patients.

Serial endovaginal sonography of ectopic pregnancies treated with methotrexate.

Methotrexate therapy is a newly established treatment modality for ectopic pregnancy. We performed this study to determine the time frame for resolution of the sonographically identifiable mass during such therapy and to determine the role of sonography in the management of these patients. Eighteen patients treated with methotrexate for laparoscopically proven ectopic pregnancy consented to long-term follow-up with endovaginal sonography. These 18 patients constitute the study group. The time required for sonographic resolution of the mass was variable, although poor patient compliance with sonographic follow-up affected the conclusions regarding resolution time. One hundred eight days was the longest period accurately known for resolution of a mass. In seven patients, the mass persisted after a negative hCG titer. Enlargement of the adnexal mass during therapy did not necessarily predict treatment failure, as only two of ten such patients required surgery for rupture. Serial sonography did not alter the management of most patients and appears not to be warranted on a routine basis. Follow-up sonography was most useful when complications were suspected. All patients considered for methotrexate therapy should first have an endovaginal sonogram, as cardiac activity remains a relative contraindication to this treatment. We have determined that the mass of an ectopic pregnancy may remain after the hCG is negative. Therefore, a persistent mass should not be interpreted as treatment failure.

Diagnosis of early embryonic demise by endovaginal sonography.

To determine the embryonic size at which cardiac activity is always seen in a normal early pregnancy, 398 endovaginal sonograms were evaluated in which the gestational sac contained a yolk sac and/or embryo of less than or equal to 12 mm in crown-rump length (CRL). In the 99 sonograms in which there was a yolk sac but no identifiable embryo, cardiac activity was absent in 75; 58 of these pregnancies progressed normally. Of the 299 sonograms where there was an identifiable embryo with CRL less than or equal to 12 mm, cardiac activity was absent in 31; 29 of these were proven to be failed pregnancies. In two cases the pregnancy progressed normally; the CRL was 2 mm in one case and 4 mm in the other. We conclude that once an embryo is seen by endovaginal sonography, the absence of cardiac activity usually indicates embryonic demise. However, when cardiac activity is absent, one should refrain from definitively diagnosing embryonic demise, based on a single sonogram, if the CRL is less than 5 mm.

Anomalous systemic and pulmonary venous pathways diagnosed in utero by ultrasound.

Anomalies of systemic and pulmonary venous return are found as either isolated lesions or as part of a complex cardiac malformation. Specifically, these venous pathway malformations are associated frequently with the cardiac defects in asplenia or polysplenia. This report describes the prenatal ultrasound diagnosis of both anomalous pulmonary and systemic venous drainage in three late gestation fetuses with a splenic syndrome and complex congenital heart disease. In addition, the utility of color-flow Doppler as an aid in making the diagnosis is emphasized.

Ultrasound of the fetal thymus.

A prospective study was performed in 340 obstetric sonograms to evaluate the sonographic characteristics of the fetal thymus. The thymus was identified as a homogeneous structure in the anterior fetal mediastinum in 251 cases (74%). The thymus was categorized as either hyperechoic, isoechoic, or hypoechoic relative to fetal lung. Seventy one of 115 cases (62%) prior to 27 weeks gestation were hyperechoic relative to fetal lung whereas 100 of 136 cases (73%) after 27 weeks were hypoechoic relative to lung (p less than .0001). Thymic measurements and shape were also recorded. The anterior-posterior AP thickness, measured in the midline at the sternum, ranged from 2 mm at 14 weeks to 20.8 mm at term. This study demonstrates that the thymus can be imaged in most fetuses.

The peripheral hypoechoic rim of the fetal heart.

The purpose of this study is to determine the origin of the hypoechoic rim around the fetal heart; this rim has been noted previously but there is disagreement as to its origin. Of 314 fetuses scanned, a four-chamber view was obtained in 290; a hypoechoic rim was present in 94% of these. In all cases in which a short-axis view could be obtained, the rim continued circumferentially through the ventricular septum. Because the rim continues through the septum, it cannot be pericardial fluid but is instead part of the myocardium. The presence as well as the origin of this normal hypoechoic rim around the fetal cardiac ventricles should be considered before diagnosing small pericardial effusions.