Monozygotic twins discordant for trisomy 13.

Monozygotic twins with discordant karyotypes are rare. We report a case of monozygotic twins discordant for trisomy 13 by amniocyte karyotypes. Ultrasound revealed multiple congenital anomalies in Twin A (47,XY,+13), none in Twin B (46,XY), and monochorionic-diamniotic placentation. Zygosity testing performed both prenatally and after birth supported monozygosity. Twin A died in the neontal period. Twin B survived and had normal physical examination, but peripheral blood karyotype revealed 20% mosaicism for trisomy 13. Monochorionic-diamniontic placentation with vascular anastomoses was confirmed by pathological examination. In this paper, we discuss the various mechanisms by which monozygotic twins may have discordant karyotypes. The surviving twin, structurally and developmentally normal at 6 months of age, will be monitored for potential complications of uniparental disomy of chromosome 13 and trisomy 13 mosaicism.

Color flow mapping and Doppler velocimetry in the diagnosis and management of a placental chorioangioma associated with nonimmune fetal hydrops.

BACKGROUND: Placental chorioangiomas are the most common tumors of the placenta, occurring in 1% of all pregnancies. With the increasing use of ultrasound, prenatal recognition of these tumors is becoming more common. CASE: A 36-year-old woman presented at 28 weeks' gestation with an intrauterine mass suggested by color flow and Doppler studies to be a vascular tumor. Because of the association of these findings to nonimmune fetal hydrops, management included umbilical blood sampling and intravascular transfusion for fetal anemia. This intervention temporarily corrected the hydrops and significantly prolonged the pregnancy. CONCLUSION: Color flow mapping and Doppler flow studies of intrauterine tumors associated with fetal nonimmune hydrops can be helpful in both diagnosis and management.

The use of a neural network for the ultrasonographic estimation of fetal weight in the macrosomic fetus.

The error associated with regression analysis methods for the ultrasonographic estimation of fetal weight in the suspected macrosomic fetus, approximately 10%, is clinically unacceptable. This study was undertaken to evaluate the applicability of an emerging technique, biologically simulated intelligence, to this problem. One hundred patients with suspected macrosomic fetuses underwent ultrasonographic measurements of biparietal diameter, head and abdominal circumference, femur length, abdominal subcutaneous tissue, and amniotic fluid index. The biologically simulated intelligence model included gestational age, fundal height, age, gravidity, and height. The model was then compared with results obtained from previously published formulas relying on the abdominal circumference and femur length. The biologically simulated intelligence yielded an average error of 4.7% from actual birth weight, statistically better (p = 0.001) than the results obtained from regression models.

Fetal abdominal abnormalities associated with genetic syndromes.

Sonographic technology has given the prenatal diagnostician the ability to accurately visualize fetal malformations. This article demonstrates the currently available capability of applying sonographically derived information concerning fetal dysmorphology to our knowledge of genetic disorders and syndromes. As a result, there can be a significant improvement in the management and counseling of these patients. After an initial discussion of normal embryology, principles of abdominal ultrasonography are discussed and applied to the following anomalies: omphalocele, gastroschisis, diaphragmatic hernia, duodenal atresia, other intestinal atresias and stenoses, renal anomalies, and obstructive uropathies.

Ultrasonographic diagnosis of a fetal abdominal mass: a case of a mesenchymal liver hamartoma and a review of the literature.

A case of a prenatally recognized hepatic mesenchymal hamartoma is presented and the literature reviewed. These tumors are benign and usually present in early infancy with symptoms that are related to the mass effect on adjacent organs. Radiologic methods used in the past to image this tumor include angiography and ultrasound. However, there is no specific radiologic finding, and, therefore, the diagnosis is usually made during surgery. Once the tumor is removed, the prognosis is generally good. With the increasing use of high resolution ultrasound in prenatal diagnosis, this rare tumor should be considered in the differential diagnosis of any multicystic mass found in the fetal abdomen. The recognition of a mass should then alert the physician to the need for early neonatal intervention.

Ultrasonographic estimation of fetal weight in the clinically macrosomic fetus.

The purpose of this study is to evaluate models for the prediction of birth weight in fetuses suspected of being macrosomic. A total of 141 patients with standard measurements of the head, abdomen, and femur were studied. Linear regressions were performed with single parameters, squares, and all possible cross products in the generation of models with log (birth weight) and birth weight as dependent variables. These models were then compared with a group of previously published equations. Clinically, all models performed poorly. However, two models were significantly less accurate in the prediction of birth weight (p less than or equal to 0.05). The best results were obtained by equations that used abdominal circumference and femur length measurements. There was no improvement in models that contained log (birth weight) or birth weight as dependent variables or models with complex variables such as squares or cross products of measured parameters. In conclusion, when evaluating patients at risk of macrosomia, the best estimates of fetal weight can be obtained by models that contain abdominal circumference and femur length.