Persistence of a monosomic cell line in a fetus with mosaic trisomy 8.

We report on a fetus presenting with an increased nuchal translucency, in which chorionic villus sampling led to the diagnosis of mosaic trisomy 8. Ultrasound scan performed at 15(+6) weeks revealed bilateral cleft lip and palate, flat facial profile, and arrhinia. Pregnancy was terminated at 16(+6); postmortem examination showed additional findings including hypospadias, bilateral renal dysplasia, and focal portal fibrosis of the liver. In order to confirm the presence of trisomy 8, FISH analysis was performed in abnormal renal and hepatic tissue, which, unexpectedly, showed a higher fraction of cells with only one fluorescent probe signal (43% and 23%, respectively), if compared with normal fetal liver and kidney (3-10%). This finding is consistent with the survival in this fetus of a monosomic cell line after mitotic non-disjunction, which is in contrast with what is generally thought about mosaic trisomy genesis. We hypothesize that the possible persistence of the monosomic cell line, in addition to the variable distribution of aneuploid cells in the body tissues, could explain the high heterogeneity of mosaic trisomy 8 phenotype.

The prognostic role of uterine artery Doppler studies in patients with late-onset preeclampsia.

OBJECTIVE: To evaluate the usefulness of uterine artery Doppler in the prediction of outcome in patients with late-onset preeclampsia. STUDY DESIGN: Patients with late-onset preeclampsia underwent Doppler interrogation of the uterine arteries. Patients with abnormal uterine artery Doppler were compared with those who had a normal uterine artery Doppler. RESULTS: Ninety-nine patients were included in the study group. Abnormal uterine artery Doppler group presented significantly lower gestational age at admission (36.1 +/- 2.1 weeks vs 37.2 +/- 1.9 weeks; P < .005), lower gestational age at delivery (36.5 +/- 1.9 weeks vs 37.7 +/- 1.7 weeks; P < .005), lower birthweight (2429 +/- 590 g vs 3013 +/- 597 g; P < .0001), and a higher admission rate to neonatal intensive care unit (17/51 vs 6/48; odds ratio, 3.5; 95% confidence interval, 1.2-9.5). No significant difference in the occurrence of maternal complications (10/51 vs 6/48; odds ratio, 1.7; 95% confidence interval, 0.5-4.9) was registered. CONCLUSION: Women with late-onset preeclampsia show a higher risk of perinatal complications if uterine resistance is increased although maternal outcome does not seem to be related to Doppler findings.

Endoscopic fetal surgery: in vitro thermic effect of electrosurgical units.

OBJECTIVE: The study focused on the safety of electrosurgical devices in endoscopic fetal surgery. The thermic effects of monopolar electric waves were studied in vitro in order to obtain safety indications in terms of mode of intramniotic application of electrical devices (time and number of shots; volts; and distance from tissues to be preserved). STUDY DESIGN: A glass model filled with saline solution, and an electrical device with resistor and voltage supply, were constructed to reproduce the physical effects of thermic conductivity in vitro; a Swan-Ganz thermic sensor was used to measure the temperature inside the beuta. Different series of tests were carried out. RESULTS: The maximal increase (8.60 +/- 0.04 degrees C) takes place at the external surface of the resistor (distance: 0 cm), while at 2 cm, the temperature of the saline solution does not change. CONCLUSIONS: Our tests demonstrate that in order to avoid any kind of risk during electrosurgical procedures on fetuses, the electrode must be placed at least 0.5 cm from delicate tissues.

Fetal thrombocytopenia secondary to parvovirus infection.

OBJECTIVE: The aim of this study was to determine the platelet count in fetuses undergoing cordocentesis for hydrops caused by parvovirus infection. STUDY DESIGN: Fetal platelets were measured at cordocentesis in 11 pregnant women who underwent the procedure because of fetal ascites and/or hydrops caused by parvovirus infection. Thrombocytopenia was defined as mild (platelet count < 150 x 10(9)/L), moderate (platelet count < or = 100 x 10(9)/L), or severe (platelet count to < or = 50 x 10(9)/L). Paired Student t test was performed to compare the platelet count before and after the transfusion. RESULTS: The fetuses underwent 20 cordocenteses. They were thrombocytopenic in 17 and anemic in 15 occasions. The platelet count was reduced after the transfusion (P < .05). Demises occurred after the first transfusion in 2 fetuses. The first occurred within 5 minutes from the procedure and the second within 24 hours. Both were attributed to exsanguination from the umbilical cord puncture site (platelet count 2 and 24 x 10(9)/L, respectively). CONCLUSION: Thrombocytopenia is common in fetuses with hydrops caused by parvovirus infection, and can cause exsanguination from the umbilical cord puncture site. We recommend platelet transfusion during cordocentesis when there is severe thrombocytopenia.

Middle cerebral artery peak systolic velocity: technique and variability.

OBJECTIVE: Assessment of the middle cerebral artery (MCA) peak systolic velocity (PSV) can accurately diagnose fetal anemia and has decreased the number of invasive procedures, such as amniocentesis and cordocentesis. The objective of this investigation was to evaluate the intraobserver and interobserver variability as a measure of reproducibility of MCA PSV. The technique of correctly sampling this vessel is described. METHODS: The study population included 30 appropriate-for-gestational-age fetuses. In each fetus, MCA PSV was determined proximal to the transducer at 3 different locations: 2 mm after its origin from the internal carotid artery, at the midlength between its origin and division, and at its division. The peak systolic velocity was also determined at the contralateral MCA 2 mm after its origin. With each measurement (obtained at 2 different institutions), care was taken to ensure that the ultrasound beam was parallel to the artery for its entire length. The reliability of an angle corrector was also assessed. The intraobserver and interobserver reliabilities were determined from the appropriate version of the intraclass correlation. RESULTS: Gestational age at study entry ranged from 14 to 37.5 weeks (median, 23.6 weeks). The proximal MCA, 2 mm after its origin from the internal carotid artery, had the best intraobserver and interobserver variability in both institutions. (Intraclass correlation ranged from 0.98 to 0.99.) CONCLUSIONS: Our data indicate that fetal MCA PSV is optimally measured soon after the MCA's origin from the internal carotid artery. Given the importance of clinical decision making based on this measurement, sonographers and sonologists interested in measuring MCA PSV should test their variability after a suitable period of training.

Fetal anemia: new technologies.

PURPOSE OF REVIEW: The purpose of this review is to summarize recently published studies on noninvasive diagnosis of fetal anemia in order to give recommendations for the use of these new tools. RECENT FINDINGS: Red cell alloimmunization remains one of the most common causes of fetal anemia. Amniocentesis and cordocentesis have been used for many years to diagnose fetal anemia due to red cell aloimmunization. These techniques, however, are invasive and many complications are associated with their use. Noninvasive diagnosis of fetal anemia has been performed with Doppler ultrasonography. Based on robust data, several authors recommend the use of middle cerebral artery peak systolic velocity in the management of fetuses at risk for anemia because of red cell alloimmunization. This Doppler parameter can also diagnose fetal anemia due to other conditions. SUMMARY: Middle cerebral artery peak systolic velocity appears to be the best test for the noninvasive diagnosis of fetal anemia. It is important to emphasize that training of sonographers and sonologists is the 'conditio sine qua non' for the correct sampling of the middle cerebral artery.