Is neonatal risk from vasa previa preventable? The 20-year experience from a single medical center.

BACKGROUND: Vasa previa is a rare condition associated with neonatal morbidity and mortality that may be diagnosed prenatally using transvaginal sonography. The aim of this study was to assess the prenatal detection of vasa previa and its subsequent impact on neonatal outcomes in two 10-year periods (1988-1997 versus 1998-2007). METHOD: Retrospective review of all cases of vasa previa. Data on obstetrical history, modes of conception, sonographic scans, delivery mode, and neonatal outcome were retrieved and recorded. RESULT: There were 19 pregnancies (21 neonates) with confirmed vasa previa (overall incidence of 1.7/10,000 deliveries). Vasa previa were diagnosed prenatally in 10 (52.6%) cases. In cases without prenatal diagnosis, there was a higher proportion of neonates with 1' Apgar score < or = 5 and cord blood pH <7 compared with cases diagnosed prenatally (66.7% versus 10%, p < or = 0.05, and 33.3% versus 0%, p < 0.05, respectively). The prenatal detection rate of vasa previa increased from 25 to 60% between the 2 time periods (p > 0.05), whereas perinatal mortality and 1' Apgar scores < or = 5 decreased from 25 to 0% and from 50 to 33.3% (p > 0.05). CONCLUSION: Prenatal sonographic screening using targeted scans for vasa previa in women at risk or as part of routine mid-gestation scanning may significantly impact its obstetric manifestations.

Second trimester ultrasound prenasal thickness combined with nasal bone length: a new method of Down syndrome screening.

OBJECTIVE: To evaluate ultrasound prenasal thickness (PT) as a way of enhancing the Down syndrome (DS) screening performance of second-trimester nasal bone (NB) length measurement. METHODS: Twenty-one DS and 500 normal fetuses were scanned at 14-27 weeks' gestation. The affected karyotype was known to the person performing the scan. Both PT and NB were measured in a mid-sagittal position and results were expressed in multiples of the normal gestation-specific median (MoM). Gaussian modelling was used to predict the performance of routine screening. RESULTS: Among DS fetuses, the PT median was 1.35 MoM, a highly statistically significant increase compared with the unaffected pregnancies (p < 0.0001, Wilcoxon Rank Sum Test, two-tailed). The NB median was 0.87 MoM (p < 0.0005) and the ratio PT/NB median was 1.51 MoM (p < 0.0001). In the normal fetuses, the two markers were positively correlated (0.25, p < 0.0001), whereas in the DS fetuses there was a non-significant negative correlation (-0.24, p = 0.33). For a 5% false-positive rate, the model predicted detection rate was 70% for PT and NB compared with 43% for NB alone. CONCLUSION: In the second trimester, PT is increased on average in DS fetuses. Combining PT and NB measurement could yield a higher screening detection rate than NB alone. Confirmation of our findings in a series of women scanned before the karyotype was known is needed before the method can be clinically implemented.

Tumor necrosis factor promotes human T-cell development in nonobese diabetic/severe combined immunodeficient mice.

A major problem after clinical hematopoietic stem cell transplantations is poor T-cell reconstitution. Studying the mechanisms underlying this concern is hampered, because experimental transplantation of human stem and progenitor cells into nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice usually results in low T-lymphocyte reconstitution. Because tumor necrosis factor alpha (TNFalpha) has been proposed to play a role in T-lineage commitment and differentiation in vitro, we investigated its potential to augment human T-cell development in vivo. Administration of TNF to irradiated NOD/SCID mice before transplantation of human mononuclear cells from either cord blood or adult G-CSF-mobilized peripheral blood (MPBL) led 2-3 weeks after transplantation to the emergence of human immature CD4(+)CD8(+) double-positive T-cells in the bone marrow (BM), spleen, and thymus, and in this organ, the human cells also express CD1a marker. One to 2 weeks later, single-positive CD4(+) and CD8(+) cells expressing heterogenous T-cell receptor alpha beta were detected in all three organs. These cells were also capable of migrating through the blood circulation. Interestingly, human T-cell development in these mice was associated with a significant reduction in immature lymphoid human CD19(+) B cells and natural killer progenitors in the murine BM. The human T cells were mostly derived from the transplanted immature CD34(+) cells. This study demonstrates the potential of TNF to rapidly augment human T lymphopoiesis in vivo and also provides clinically relevant evidence for this process with adult MPBL progenitors.

Correlation and overlapping between nuchal translucency and triple test among Down syndrome-affected pregnancies.

OBJECTIVES: To examine the correlation and extent of overlapping between first-trimester nuchal translucency (NT) and second-trimester triple test (TT) results in Down syndrome (DS)-affected pregnancies. METHODS: Results of both tests were obtained in 28 cases with DS. Inter-test correlation was performed by comparing the likelihood ratios (LRs). Screen-positive rates (risk >1:380) were calculated for different age groups by adjusting age-dependent background risk and tests' LRs. Overlapping referred to ratio between screen-positive cases by both tests simultaneously and total screen-positive cases by either one or both tests. RESULTS: No correlation was found between the tests' LRs (Pearson correlation test, r = 0.0487). The overlapping between the tests was 25% and 38.5% among young patients of 20 and 35 years of age, respectively. The average overlapping among patients between 25 and 35 years of age was approximately 33%. Only 3 of the 28 DS cases demonstrated LRs <1 by both tests and moreover none exhibited LRs <0.2 by both tests. CONCLUSIONS: The degree of overlapping of one third, between NT and TT, confirms the assumption that both tests utilized together improves DS detection. Screen- negative result, by both tests simultaneously, may reassure low-risk population and aid to reduce the number of non-indicated invasive tests.