Donald S. Emerson

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.

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.

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.

Transabdominal chorionic villus sampling for first-trimester prenatal diagnosis

We report here our technique and initial experience with transabdominal chorionic villus sampling for first-trimester prenatal diagnosis at the University of Tennessee, Memphis. Eighty-seven patients underwent transabdominal chorionic villus sampling between 9 and 12 menstrual weeks of pregnancy. Sufficient chorionic villi (greater than or equal to 5 mg) were obtained from 83 of the 87 patients (95.4%); in 73 (88%) of the 83 successful samplings only a single needle passage was required. In one case a 47,XX, +21 complement was diagnosed; the patient elected to terminate the pregnancy and the diagnosis was confirmed in the abortus. In a second case a 46,XX,rcp(15;21)(p11;q21) woman had a fetus who also had the same balanced translocation. In a third case nonmosaic 47,XX, +16 was detected in both direct preparations of cytotrophoblast cells and cultured mesenchymal core cells. Amniocentesis performed at 15 weeks showed a normal 46,XX complement. The pregnancy continued, and the patient was delivered at term of a healthy female infant. Two spontaneous fetal losses occurred in this series, and one woman underwent an elective abortion after receiving the results of a 46,XX complement. To date, 39 of the women have been delivered and all infants are doing well; the remaining 44 pregnancies are continuing uneventfully. We conclude that transabdominal chorionic villus sampling can be a useful alternative to transcervical chorionic villus sampling, particularly when transcervical sampling is contraindicated (e.g., active genital herpes) or where the transcervical approach would be technically difficult.

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

Teleradlology, 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 teleradlology Include on-call reading, consultation and overreadlng, primary-reading teleradlology, and integration with picture archiving and communication system (PACS) and mlniPACS. Remote real-time ultrasound teledlagnosls represents a specialized subset of primary-reading teleradlology, 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 teledlagnosls extends the high standards of tertiary center sonographic diagnosis out to community and rural sites.

Initial clinical performance of a large-field KCD digital radiography system

The initial clinical performance of a research prototype digital radiographic system based on a large-field (2016-channel) kinestatic charge detector and data acquisition system is discussed. The first clinical images from the large-field system are compared with images of the same patients taken with commercial systems. Future directions are discussed.

Cartilage-Hair Hypoplasia Syndrome: Implications for Prenatal Diagnosis

Cartilage-hair hypoplasia (CHH) is a rare autosomal recessive skeletal dysplasia characterized by short stature, sparse hair, and a variable degree of immunodeficiency. We describe here the prenatal diagnosis of CHH in a woman who was previously delivered of a similarly affected infant. In addition, we review the prenatal diagnostic implications of the localization, by linkage analysis, of the gene responsible for many cases of CHH.

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.

Fetal trisomy 13 distinguished by persistent fetal tachycardia

Recent reports [1,2] have demonstrated a strong association between the first-trimester ultrasound detection of fetal structural abnormalities and aneuploidy. Offering genetic counseling and invasive prenatal diagnosis to women carrying affected fetuses is now warranted. Accordingly, ultrasound could be a useful first-trimester screening modality for detecting women at increased risk of fetal aneuploidy [2]. However, further information concerning the efficacy of first-trimester ultrasonography must be obtained before ultrasound is routinely incorporated within an obstetrical screening paradigm [31. Our patient is a 34-year-old G3P2 who was referred for counseling and chorionic villus sampling (CVS) because of advanced maternal age (35) and a child with Down’s syndrome (47,XY, +

Endovaginal Sonography of Adnexal Masses

Endovaginal sonography has become the preferred method of imaging the female pelvis. It has provided improved imaging of the ovaries and fallopian tubes and allowed more accurate diagnosis of both benign and malignant processes in the adnexa. This is a review of endovaginal adnexal imaging with emphasis on how endovaginal sonography improves the specificity in the diagnosis of specific masses of the adnexal structures.