78 research outputs found
Three-dimensional power Doppler evaluation of cerebral vascular blood flow: A novel tool in the assessment of fetal growth restriction
Evaluating the optimal definition of abnormal first-trimester uterine artery Doppler parameters to predict adverse pregnancy outcomes
Statistical analysis and interpretation of prenatal diagnostic imaging studies, part 3: Approach to study design
First-trimester 3-dimensional power Doppler placental vascularization indices from the whole placenta versus the placental bed to predict preeclampsia: Does pregnancy-associated plasma protein A or uterine artery Doppler sonography help?
Isolated short femur length on second-trimester sonography: A marker for fetal growth restriction and other adverse perinatal outcomes
Advanced Maternal Age and the Risk of Major Congenital Anomalies
ObjectiveâThis study aims to determine if advanced maternal age (AMA) is a risk factor for major congenital anomalies, in the absence of aneuploidy.
Study DesignâRetrospective cohort study of all patients with a singleton gestation presenting for second trimester anatomic survey over a 19-year study period. Aneuploid fetuses were excluded. Study groups were defined by maternal ageââ€â34 andââ„â35 years. The primary outcome was the presence of one or more major anomalies diagnosed at the second trimester ultrasound. Univariable and multivariable logistic regression analyses were used to estimate the risk of major anomalies in AMA patients.
ResultsâOf 76,156 euploid fetuses, 2.4% (nâ=â1,804) were diagnosed with a major anomaly. There was a significant decrease in the incidence of major fetal anomalies with increasing maternal age until the threshold of age 35 (pâ<â0.001). Being AMA was significantly associated with an overall decreased risk for major fetal anomalies (adjusted odds ratio: 0.59, 95% confidence interval: 0.52â0.66). The subgroup analysis demonstrated similar results for womenââ„â40 years of age.
ConclusionâAMA is associated with an overall decreased risk for major anomalies. These findings may suggest that the âall or nothingâ phenomenon plays a more robust role in embryonic development with advancing oocyte age, with anatomically normal fetuses being more likely to survive
Efficiency of first-trimester uterine artery Doppler, A-disintegrin and metalloprotease 12, pregnancy-associated plasma protein A, and maternal characteristics in the prediction of preeclampsia
OBJECTIVE: To estimate the efficiency of first-trimester uterine artery Doppler, A-disintegrin and metalloprotease 12 (ADAM12), pregnancy-associated plasma protein A (PAPP-A) and maternal characteristics in the prediction of pre-eclampsia. METHODS: This is a prospective cohort study of patients presenting for first-trimester aneuploidy screening between 11-14 weeksâ gestation. Maternal serum ADAM12 and PAPP-A levels were measured by immunoassay, and mean uterine artery Doppler pulsatility indices (PI) were calculated. Outcomes of interest included pre-eclampsia, early pre-eclampsia, defined as requiring delivery at <34 weeksâ gestation, and gestational hypertension. Logistic regression analysis was used to model the prediction of pre-eclampsia using ADAM12 multiples of the median (MoM), PAPP-A MoM, and uterine artery Doppler PI MoM, either individually or in combination. Sensitivity, specificity, and area under the receiver-operating characteristic curves (AUC) were used to compare the screening efficiency of the models using non-parametric U-statistics. RESULTS: Of 578 patients with complete outcome data, there were 54 (9.3%) cases of preeclampsia and 13 (2.2%) cases of early pre-eclampsia. Median ADAM12 levels were significantly lower in patients who developed pre-eclampsia compared to those who did not. (0.81 v. 1.01 MoMs; p<0.04) For a fixed false positive rate (FPR) of 10%, ADAM12, PAPP-A, and uterine artery Doppler in combination with maternal characteristics identified 50%, 48%, and 52% of patients who developed pre-eclampsia, respectively. Combining these first-trimester parameters did not improve the predictive efficiency of the models. CONCLUSION: First-trimester ADAM12, PAPP-A, and uterine artery Doppler are not sufficiently predictive of pre-eclampsia. Combinations of these parameters do not further improve their screening efficiency
Clinical, ultrasound and molecular biomarkers for early prediction of large for gestational age infants in nulliparous women: an international prospective cohort study
Objective: To develop a prediction model for term infants born large for gestational age (LGA) by customised birthweight centiles. Methods: International prospective cohort of nulliparous women with singleton pregnancy recruited to the Screening for Pregnancy Endpoints (SCOPE) study. LGA was defined as birthweight above the 90th customised centile, including adjustment for parity, ethnicity, maternal height and weight, fetal gender and gestational age. Clinical risk factors, ultrasound parameters and biomarkers at 14â16 or 19â21 weeks were combined into a prediction model for LGA infants at term using stepwise logistic regression in a training dataset. Prediction performance was assessed in a validation dataset using area under the Receiver Operating Characteristics curve (AUC) and detection rate at fixed false positive rates. Results: The prevalence of LGA at term was 8.8% (n = 491/5628). Clinical and ultrasound factors selected in the prediction model for LGA infants were maternal birthweight, gestational weight gain between 14â16 and 19â21 weeks, and fetal abdominal circumference, head circumference and uterine artery Doppler resistance index at 19â21 weeks (AUC 0.67; 95%CI 0.63â0.71). Sensitivity of this model was 24% and 49% for a fixed false positive rate of 10% and 25%, respectively. The addition of biomarkers resulted in selection of random glucose, LDL-cholesterol, vascular endothelial growth factor receptor-1 (VEGFR1) and neutrophil gelatinase-associated lipocalin (NGAL), but with minimal improvement in model performance (AUC 0.69; 95%CI 0.65â0.73). Sensitivity of the full model was 26% and 50% for a fixed false positive rate of 10% and 25%, respectively. Conclusion: Prediction of LGA infants at term has limited diagnostic performance before 22 weeks but may have a role in contingency screening in later pregnancy
Diagnostic strategy and timing of intervention in infected necrotizing pancreatitis: an international expert survey and case vignette study
AbstractBackgroundThe optimal diagnostic strategy and timing of intervention in infected necrotizing pancreatitis is subject to debate. We performed a survey on these topics amongst a group of international expert pancreatologists.MethodsAn online survey including case vignettes was sent to 118 international pancreatologists. We evaluated the use and timing of fine needle aspiration (FNA), antibiotics, catheter drainage and (minimally invasive) necrosectomy.ResultsThe response rate was 74% (NÂ =Â 87). None of the respondents use FNA routinely, 85% selectively and 15% never. Most respondents (87%) use a step-up approach in patients with infected necrosis. Walled-off necrosis (WON) is considered a prerequisite for endoscopic drainage and percutaneous drainage by 66% and 12%, respectively. After diagnosing infected necrosis, 55% routinely postpone invasive interventions, whereas 45% proceed immediately to intervention. Lack of consensus about timing of intervention was apparent on day 14 with proven infected necrosis (58% intervention vs. 42% non-invasive) as well as on day 20 with only clinically suspected infected necrosis (59% intervention vs. 41% non-invasive).DiscussionThe step-up approach is the preferred treatment strategy in infected necrotizing pancreatitis amongst expert pancreatologists. There is no uniformity regarding the use of FNA and timing of intervention in the first 2â3 weeks of infected necrotizing pancreatitis
Single-Photon Spectroscopy of a Single Molecule
Efficient interaction of light and matter at the ultimate limit of single photons and single emitters is of great interest from a fundamental point of view and for emerging applications in quantum engineering. However, the difficulty of generating single-photon streams with specific wavelengths, bandwidths, and power as well as the weak interaction probability of a single photon with an optical emitter pose a formidable challenge toward this goal. Here, we demonstrate a general approach based on the creation of single photons from a single emitter and their use for performing spectroscopy on a second emitter situated at a distance. While this first proof of principle realization uses organic molecules as emitters, the scheme is readily extendable to quantum dots and color centers. Our work ushers in a new line of experiments that provide access to the coherent and nonlinear couplings of few emitters and few propagating photons
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