Virtopsy in conjoined ischiopagus twins.

PURPOSE OF INVESTIGATION: To propose a multidisciplinary protocol for postmortem disclosure of complex fetal malformations, comparing ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and autopsy in a case of conjoined ischiopagus twins. MATERIALS AND METHODS: A screening second-trimester ultrasound diagnosed ischiopagus twins at 20 gestational weeks in a 31-year-old woman without any previous ultrasound examination. The couple decided for pregnancy termination. The formalin-fixed fetuses underwent full-body CT, MRI, and autopsy. RESULTS: ultrasound accurately diagnosed ischiopagus twins. CT was very accurate in the description of bone components. MRI allowed better visualization of the visceral organs than CT. Only autopsy could disclose the aspect of the two gastrointestinal tracts and the external genitalia. CONCLUSIONS: Prenatal ultrasound represents the standard diagnostic exam for conjoined twins. CT-MRI virtual autopsy (virtopsy) may be an option if the couple refuses to authorize necropsy or may be useful to plan a minimally invasive autopsy preserving the external phenotype.

Diginyc partial hydatidiform mole with increased fetal nuchal translucency and ovarian hyperstimulation syndrome.

PURPOSE OF INVESTIGATION: Hydatidiform mole (HM) is an abnormal pregnancy characterized by proliferation of cytotrophoblast and syncytiotrophoblast and vesicular swelling of placental villi. The fetus or embryo can be absent or abnormal. HMs can be complete or partial. CASE REPORT: A case of diginyc partial HM at 12 weeks of gestational age was referred to the present center of prenatal diagnosis. The patient showed ovarian hyperstimulation syndrome. At ultrasonography, increased fetal nuchal translucency (NT) with fetal anomaly was evident, without sonographic signs of placental mole. Pregnancy was terminated with legal abortion. RESULTS: Partial HM (PHM) was suspected by ultrasonographic fetal markers with ovarian hyperstimulation syndrome, but the diagnosis was performed only with fluorescent in situ hybridization. In particular fetal NT appeared increased also in diginyc mole. CONCLUSION: In order to improve the detection rate of PHM, routine histological examinations may be associated to fluorescent in situ hybridization in all cases of fetal anomalies.

Congenital defects in assisted reproductive technology pregnancies.

AIM: The aim of this study was to evaluate the prevalence and kind of congenital malformations in assisted reproductive technology (ART) pregnancies. METHODS: This study included pregnancies conceived by in-vitro fertilization (IVF) or intra cytoplasmic sperm injection (ICSI), evaluated in a referral center for prenatal diagnosis between January 2008 and December 2009. The control group included all the pregnancies examined in the same centre during in the same period of time. A computerized database was used to retrospectively identify the two study groups. RESULTS: The study evaluated 225 IVF or ICSI pregnancies (88 IVF and 137 ICSI). A congenital malformation was diagnosed in 13 pregnancies and the malformation rate was 5.8%. The number of malformed fetuses was similar in the ICSI (5.8%) or the IVF (5.7%) pregnancies. The anatomic districts more frequently involved by malformations were the encephalic one (38.5%) and the limbs (23.1%). In the control group, represented by 5,884 pregnancies, the malformation rate was 2.7%; encephalic (22.2%), urogenital (18.4%), cardiac (13.9%) CONCLUSION: In our experience on congenital defects in ART pregnancies, the encephalic district and the limbs are more frequently involved by fetal malformation. No significant difference was observed in the malformation prevalence between the IVF and the ICSI pregnancies.

Prenatal diagnosis of a nasal glioma in the mid trimester.

We report a case of fetal nasal glioma diagnosed at 21 weeks of gestation. The glioma appeared as a moderately hypoechoic mass arising from the junction between the medial aspect of the left orbit and the lateral aspect of the nose, and showing no internal vascularization on color and power Doppler ultrasonography. Fetal magnetic resonance imaging (MRI) excluded the possibility of an encephalocele by ruling out underlying bone defects. After an uneventful pregnancy, the nasal glioma was resected without complications at 4 months of age. The differential diagnosis of fetal paranasal facial masses is discussed.

A newly described thoracic vascular malformation in fetuses with Down syndrome.

OBJECTIVES: To report the association between thoracic vascular malformations observed in the first trimester of pregnancy and Down syndrome. METHODS: The clinical features were reviewed of seven fetuses undergoing chorionic villus sampling (CVS) for increased nuchal translucency (NT) thickness, in which color Doppler ultrasonography revealed a vascular malformation in the fetal thorax. RESULTS: The crown-rump length of the fetuses ranged from 58 to 78 mm and NT measurements ranged from 2.9 to 10.0 mm. Color Doppler allowed the identification of a highly vascular structure in the posterolateral portion of the fetal thorax, in proximity to the costovertebral angle, at the level of a four-chamber view of the heart. The lesions had a globular shape and were 4-6 mm in diameter, occupying almost one third of the hemithorax. Down syndrome was diagnosed in five out of the seven cases. In the only affected case that underwent postmortem examination, a hemangioma of the chest wall was demonstrated. In the two fetuses with normal karyotype, the lesion disappeared by mid-gestation. CONCLUSION: We report an association between the prenatal Doppler finding of a vascular tumor in the fetal chest and Down syndrome.

Fetal spine ossification: the gender and individual differences illustrated by ultrasonography.

The spatial and temporal pattern of manifestation of ossification nuclei of the spinal column in fetal life have been well established by histologic and radiologic studies. Sonographic evaluation of the fetal spine depends on visualization of the ossification centers, but the sequence of development of ossification centers in the vertebral column obtained by embryologists and sonographers and radiology are conflicting. We carried out a longitudinal study to establish the ultrasonographic appearance and timing of development of primary ossification centers of the fetal spine in the first and second trimesters of pregnancy. A total of 80 mothers were evaluated during their pregnancy with two echographic controls; in the first trimester, the spine length was measured and, in the second trimester of pregnancy, the timing of ossification of the bodies and neural arches of sacral vertebrae and the difference in appearance between the female and male genders were evaluated. Spinal length measurements obtained in the first trimester and percentage of detection of sacral vertebral structures increased progressively with a regular pattern in relation to gestational age. Spinal length at first ultrasound examination was slightly correlated with time of appearance of sacral bodies and arches. Ossification timing was significantly earlier in females than in males. The study has attempted to improve our understanding of the sonographic detection of the spinal ossification. Data presented give some further information on the stages of appearance of sacral vertebrae body centers during intrauterine development. Differences between genders and interindividual variations in ossification timing were observed at a very early stage of development. This could be of value when fetal growth is evaluated. Moreover, further knowledge of spinal development may be useful for early diagnosis of spinal abnormalities and for fetal biometrics.

Ossification timing of sacral vertebrae by ultrasound in the mid-second trimester of pregnancy.

OBJECTIVES: The aim of the study was to establish the ossification timing of sacral vertebrae by ultrasonography in the second trimester of pregnancy, for the diagnosis of caudal regression syndrome with isolated sacral agenesis. METHODS: The study was carried out on 77 normal single pregnancies, at gestational ages ranging from 15 to 21 weeks, using high-resolution transabdominal echography. The sacral region was visualized in a coronal plane, when the fetus was in anterodorsal position. The level of ossification of sacral vertebrae (S1 to S5) at each gestational age was recorded. Each sacral region was examined three times by the same observer and the nucleus was considered as present when it was visualized at least two times out of three. Blind assessment was performed three times by a second observer, who was not present at the previous examination, for interobserver and intraobserver error analysis. RESULTS: Interobserver and intraobserver error calculation demonstrated the reproducibility of the method. Concordance between the two observers as evaluated by Cohen Kappa index was 0.77 (C.I. 95%, 0.69-0.85).S1 ossification nuclei were visualized in all fetuses at 15 weeks and S2 nucleus was found in all fetuses within 17 weeks. S3 nucleus was detected in 45% of fetuses by the beginning of the 16th week. S4 was visualized in 55% of the cases at 18 weeks and progressively in a higher percentage of cases during the following weeks of gestation. CONCLUSION: The data obtained showed that the sequence of development of sacral region ossification was related to gestational age. This observation allows clinicians to accurately exclude isolated sacral agenesis at 16 to 17 weeks of gestation, when the S1-S2 ossification nuclei are visualized. This opportunity may be of particular value in the offspring of diabetic mothers.

Effect of fetal gender on first-trimester ductus venosus blood flow.

OBJECTIVES: Recent reports have suggested that nuchal translucency (NT) measurements in the first trimester may be influenced by fetal gender. Since both NT and central venous blood flow are considered to be related to fetal cardiac function, we investigated gender-related differences in first-trimester ductus venosus Doppler indices. METHODS: A total of 73 male and 79 female normal fetuses at 10-14 weeks of gestation were included in the study. The pulsatility index for veins (PIV), peak velocity during ventricular systole (S-wave), time-averaged maximum velocity (TAMV) and A-wave velocity (A-wave) were recorded in each case and converted to the corresponding Z-scores. RESULTS: The mean Z-score values of PIV, S-wave and TAMV were significantly lower in male fetuses compared to female fetuses (P < 0.01 for all three indices). By contrast, A-wave velocities were not different in the two groups. The correlation between S-wave velocity and TAMV was significant in both male (P < 0.001) and female (P < 0.001) fetuses, while PIV did not appear to be related to TAMV either in males (P = 0.90) or in females (P = 0.49). A-wave velocity had a significant negative correlation with PIV in both groups. Finally, PIV was significantly correlated with S-wave velocity in female fetuses (P < 0.01) but not in males (P = 0.14). CONCLUSION: These findings suggest that early cardiovascular development may be different in male and female fetuses.

Ultrafast MR imaging of the foetus: a study of 25 non-central nervous system anomalies.

PURPOSE: The aim of this paper is to suggest Magnetic Resonance (MR) Imaging as a useful tool in prenatal diagnosis. Although ultrasonography (US) is the imaging technique of choice for prenatal screening, in cases of complex malformations US findings may be sub-optimal and give rise to diagnostic difficulties requiring further investigation. Our study is focused on non-central nervous system (CNS) abnormalities of the foetus imaged using the ultrafast sequence EXPRESS. MATERIALS AND METHODS: 38 women whose foetuses were between 21-34 gestational age were studied. Indications for the examinations included the evaluation of non-CNS abnormalities in 25 cases. Foetal MR imaging was performed on a 1.5 T system (Edge, Marconi Medical System Italia SpA, Vimercate, MI) with the half-Fourier, single-shot, fast spin-echo EXPRESS sequence. Mild maternal and foetal sedation was obtained by oral administration of benzodiazepine (1 mg). RESULTS: In the 25 foetuses investigated for non-CNS pathologies the abnormalities were localised in the chest (9), abdomen (15) and extremities (1). The MR imaging diagnoses were: in the chest - congenital diaphragmatic hernia (CDH) (5), congenital cystic adenomatoid malformation (CCAM) (1), hydrothorax (1), cystic lymphangioma (1), Jeune syndrome (1); in the abdomen - 10 cases of urinary tract diseases - polycystic kidney (4), crossed renal ectopia (2), unilateral renal agenesis (1), solitary pelvic kidney (1), bilateral stenosis of ureteropelvic junction (1), duplex collecting system in association with controlateral hydroureteronephrosis (1)#151;5 cases of non-urinary tract pathologies#151;cystic lymphangioma of the liver (1), abdominal cystic lymphangioma (1), gastroschisis (1), gastric duplication (1), cavernous haemangioma of the liver (1); in the extremities - longitudinal hemimelia (1). CONCLUSIONS: In our experience MR is to be considered a useful though adjunct study to prenatal US particularly in the evaluation of lung parenchyma, congenital diaphragmatic viscera herniation, thoracic masses, pleural effusion, abdominal cystic masses, and urinary tract malformations. The ultrafast EXPRESS sequence enables a complete study to be performed in a very short time; as a consequence the examination is well tolerated by the patient. Currently there is no legislation which regulates the use of magnetic fields in MR, only a series of recommendations based on studies on animal embryos and foetuses, on pregnant women exposed to magnetic fields and follow-up studies of children exposed to MR during gestation. Therefore the decision to proceed with foetal MR should be made on a case-by-case basis in close consultation with the referring obstetrician. Considering the results, in our opinion the potential of MR in the evaluation of a wide variety of non-CNS foetal diseases will increase in the near future.

Spine length measurement in the first trimester of pregnancy.

OBJECTIVES: The aim of the study was to evaluate spine length as an indicator of skeletal growth in the first trimester of pregnancy and to provide a nomogram of spine length at the end of the first trimester of pregnancy. METHODS: The study was carried out on 420 single pregnancies, at gestational ages ranging from 11 to 14 weeks, using high-resolution transabdominal echography. Biparietal diameter and crown-rump length (CRL) were measured to date the pregnancy. Using the same scanning plane used to measure CRL, the whole spine length in antero-dorsal position can be visualized as a double hyperechoic line from 10 weeks of gestation onwards. Spine length was measured three times by one observer and the mean of the three measurements was considered as definitive. Forty fetuses had multiple measurements for interobserver and intraobserver error analysis. RESULTS: Linear relationship between spine length, and gestational age, biparietal diameter and CRL were demonstrated. Spine length (millimetres) as a function of gestational age (days) was expressed by the regression equation: spine length = 1.09 x (gestational age in days) -60.56, with a determination coefficient of R(2) = 0.744. Spine length ranged from 21.5 mm at 11 weeks to 41.9 mm at 14 weeks. CONCLUSION: The data obtained showed that spine length increased progressively from the end of the first trimester to the beginning of the second. A high correlation between spine length, gestational age, biparietal diameter, and CRL was observed. Spine length measurement could therefore be considered a good indicator of fetal growth.

Reference values for ductus venosus Doppler flow measurements at 10-14 weeks of gestation.

OBJECTIVES: To calculate reference ranges for ductus venosus Doppler measurements obtained transabdominally at 10-14 weeks of gestation. DESIGN: Two hundred and one normal fetuses with a crown-rump length (CRL) ranging from 38 to 88 mm were examined in a cross-sectional study. The pulsatility index for veins (PIV), peak velocity during ventricular systole (S-wave), lowest forward velocity during atrial contraction (A-wave) and time-averaged maximum velocity (TAMXV) were recorded from the ductus venosus. Flow velocity waveforms were also classified as normal or abnormal according to the presence (normal) or absence or reversal (abnormal) of frequencies during atrial contraction. RESULTS: Three of 201 fetuses showed an abnormal flow pattern (1.5%; 95% exact confidence interval, 0.3-4.3%). In the 198 fetuses with a normal flow pattern, the mean PIV ranged from 1.07 at a CRL of 38 mm to 1.00 at a CRL of 88 mm (r = -0.093; P = 0.19). A significant increase in mean blood flow velocity with increasing CRL was noted for the S-wave (27.0 cm/s to 33.6 cm/s; r = 0.17; P = 0.02), the A-wave (5.9 cm/s to 7.8 cm/s; r = 0.14; P = 0.04) and the TAMXV (19.4 cm/s to 25.3 cm/s; r = 0.19; P < 0.01). Crown-rump length-specific reference ranges for each parameter were calculated using the method of scaled absolute residuals. CONCLUSIONS: Abnormal ductus venosus flow patterns could be observed in normal fetuses, even if they ocurred with a low prevalence. Reference values for Doppler measurements were established in fetuses with normal patterns of flow.

Reference values for fetal limb biometry at 10-14 weeks of gestation.

OBJECTIVES: To calculate reference ranges for fetal limb measurements obtained by transabdominal ultrasound at 10-14 weeks of gestation. METHODS: Six hundred and six normal fetuses were examined transabdominally in a cross-sectional study by a single observer. The crown-rump length of the fetuses ranged from 31 to 78 mm. Measurement of the length of the humerus, ulna, femur, tibia and foot was attempted from the longest section of each structure. To assess intraobserver repeatability, three sets of repeated measurements were obtained in 26 fetuses. RESULTS: An appropriate ultrasound measurement was obtained in a percentage of cases ranging from 93.2% to 97.9%. A significant correlation was found between crown-rump length measurements and humerus length (r = 0.74, P < 0.001), ulna length (r = 0.70, P < 0.001), femur length (r = 0.77, P < 0.001), tibia length (r = 0.69, P < 0.001) and foot length (r = 0.58, P < 0.001). Crown-rump length-specific reference ranges for each measurement were calculated with the method of scaled absolute residuals. The study of intraobserver variability showed coefficients of variation ranging from 7.9 to 10.0% and intraclass correlation coefficients ranging from 0.89 to 0.94. CONCLUSIONS: Fetal limb size is strongly correlated with crown-rump length. Despite a significant biological variability of the measurements, the availability of reference ranges could be of help in the early diagnosis of fetal skeletal dysplasias.

Reproducibility of ductus venosus Doppler flow measurements at 11-14 weeks of gestation.

OBJECTIVES: To assess the intra- and interobserver repeatabilities of fetal ductus venosus Doppler measurements at 11-14 weeks of gestation. DESIGN: Flow velocity waveforms were recorded transabdominally. Intraobserver repeatability was studied in 22 fetuses in whom four repeated measurements were performed by the same observer. Interobserver repeatability was assessed in 54 fetuses in each of whom two observers performed two repeated measurements. The pulsatility index for veins (PIV), peak velocity during ventricular systole (S wave), peak velocity during atrial contraction (A wave) and time-averaged maximum velocity (TAMV) were recorded. Reproducibility of the Doppler measurements was analyzed by calculating repeatability coefficient, coefficient of variation (CV), intraclass correlation coefficient (ICC), mean differences and their limits of agreement. Cohen's k-coefficient was used for categorical data. RESULTS: Intraobserver repeatability was good with a CV of 10%, 13%, 22% and 13% and an ICC of 0.85, 0.94, 0.94 and 0.95, respectively, for PIV, S wave, A wave and TAMV. Interobserver repeatability was also good, and no bias between the observers was detected. A CV of 8.8%, 14%, 27% and 15% and an ICC of 0.86, 0.84, 0.87 and 0.84, respectively, for PIV, S wave, A wave and TAMV were obtained. There was 100% agreement for the detection of normal/abnormal blood flow. CONCLUSIONS: Intra- and interobserver repeatability of all parameters was acceptable, allowing for the detection of moderate to large changes in Doppler measurements.

Sonographic and molecular diagnosis of thanatophoric dysplasia type I at 18 weeks of gestation.

Thanatophoric dysplasia is the most common type of lethal skeletal dysplasia. It can usually be diagnosed with ultrasound, but differential diagnosis with other osteochondrodysplasias is not always possible. Mutations in the fibroblast growth factor receptor 3 (FGFR3) gene have been demonstrated to cause two distinct subtypes of the disorder. We describe a case of thanatophoric dysplasia type I diagnosed at 18 weeks of gestation by ultrasonography. Genomic DNA obtained by chorionic villus sampling showed a C to G substitution at position 746 in the FGFR3 gene, resulting in a Ser249Cys substitution already known to be associated with type I disease. Implications for perinatal management are discussed.

Flow cytometric and functional characterization of AC133+ cells from human umbilical cord blood.

AC133+ cells may represent an alternative source of transplantable haemopoietic progenitor cells to CD34+ cells. Here, we have addressed the characterization of umbilical cord blood (UCB) AC133+ cells and compared their immunophenotypic and functional features with those of UCB CD34+ cells. UCB AC133+ and CD34+ cell fractions were purified by magnetic cell sorting, analysed by flow cytometry, tested for their content in blast cell colony-forming units (CFU-Bl), erythroid and granulocyte-macrophage colony-forming units before and after expansion in the presence of various haemopoietic growth factor combinations. Median AC133+ cell yield was 62.3%, and median AC133+ population purity was 97.9%. AC133+ cells were found to contain significantly more CFU-Bl than CD34+ cells; furthermore, the replating efficiency, i.e. the number of CFU-Bl capable of generating secondary colonies, was higher in the former than in the latter cells. Both AC133+ and CD34+ cells displayed an increased ability to give rise to committed progenitors after 7-day expansion in liquid cultures. These data suggest that the AC133+ cell subset is a heterogeneous pool of immature and more differentiated cells that can be maintained and expanded in well-defined culture conditions. In comparison with CD34+ cells, UCB AC133+ cells appear to contain a higher number of early haemopoietic progenitors.