32 research outputs found

    Perinatal Loss at Term: The Role of Uteroplacental and Fetal Doppler Assessment.

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    OBJECTIVE: To examine the association of uterine artery (UtA) Doppler indices and cerebroplacental ratio (CPR) on perinatal outcome at term. METHODS: This retrospective cohort study conducted in a single tertiary referral centre included all singleton pregnancies undergoing ultrasound assessment in the third trimester, which subsequently delivered at term. Fetal biometry and Dopplers including the umbilical artery (UA), middle cerebral artery (MCA) and uterine artery were recorded. Data was corrected for gestational age and CPR was calculated as a ratio between the MCA pulsatility index (PI) and UA PI. Logistic regression analysis was conducted to examine for independent predictors of adverse perinatal outcome. RESULTS: The study included 7013 pregnancies; 12 were complicated by perinatal death. When compared to pregnancies resulting in live birth, pregnancies complicated by perinatal death had significantly more small for gestational age (SGA) infants (27.3% vs 5%, p = 0.001) and a higher incidence of low CPR (16.7% vs 4.5%, p = 0.041). A subgroup analysis comparing 1527 low risk pregnancies demonstrated that the UtA PI MoM, CPR <5(th) centile and estimated fetal weight (EFW) centile were all significantly associated with the risk of perinatal death at term (all p < 0.05). After adjusting for confounding variables, only EFW (OR 0.96, 95% CI 0.93-0.99; p = 0.003) and UtA PI MoM (OR 13.10, 95%CI 1.95-87.89; p = 0.008) remained independent predictors of perinatal death in the low risk cohort. CONCLUSION: High uterine artery PI at term is independently associated with increased risk of adverse perinatal outcome regardless of fetal size. These results suggest that perinatal mortality at term is related, not only to EFW and fetal redistribution (CPR), but also to indices of uterine perfusion

    Accuracy of the fetal cerebroplacental ratio for the detection of intrapartum compromise in nonsmall fetuses.

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    OBJECTIVE: To study the accuracy of the cerebroplacental ratio (CPR) for the detection of intrapartum fetal compromise (IFC) in fetuses growing over the 10th centile. METHODS: This was a prospective study of 569 nonsmall fetuses attending the day hospital unit of a tertiary hospital that underwent an ultrasound examination at 36-40 weeks, and were delivered within 4 weeks of examination. IFC was defined as a composite of: abnormal intrapartum fetal heart rate or intrapartum fetal scalp pH < 7.20 requiring cesarean section, neonatal umbilical cord pH < 7.20, 5' Apgar score < 7 and postpartum admission to neonatal or pediatric intensive care units. The accuracy of CPR for the prediction of IFC was calculated alone and in combination with other perinatal parameters using univariate and multivariate logistic regression models, which alternatively included the onset of labor to evaluate the influence of induction of labor (IOL) on IFC and a brief composite adverse outcome of two parameters to prove the strength of the approach. RESULTS: The incidence of IFC was 17.9%. CPR sensitivity was 30.4% for a false positive rate (FFR) of 10 and 14.7% for a FPP of 5% (AUC = 0.62, p < 0.001). The multivariate analysis showed that only fetal gender and parity increased the predictive accuracy of CPR alone, although the improvement was poor (AUC = 0.67, p < 0.001). No differences were observed using any of the alternative models. Finally, IOL had no influence of IFC. CONCLUSION: Despite their apparent normality, a proportion of fetuses growing over the 10th centile suffer IFC. Some of them are suitable for detection by means of CPR

    Progression of Doppler changes in early-onset small for gestational age fetuses. How frequent are the different progression sequences?

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    OBJECTIVE: To evaluate the progression of Doppler abnormalities in early-onset fetal smallness (SGA). METHODS: A total of 948 Doppler examinations of the umbilical artery (UA), middle cerebral artery (MCA) and ductus venosus (DV), belonging to 405 early-onset SGA fetuses, were studied, evaluating the sequences of Doppler progression, the interval examination-labor at which Doppler became abnormal and the cumulative sum of Doppler anomalies in relation with labor proximity. RESULTS: The most frequent sequences were that in which only the UA pulsatility index (PI) became abnormal (42.1%) and that in which an abnormal UA PI appeared first, followed by an abnormal MCA PI (24.2%). In general, 71.3% of the fetuses followed the classical progression sequence UA→MCA→DV, mostly in the early stages of growth restriction (84.1%). In addition, the UA PI was the first parameter to be affected (9 weeks before delivery), followed by the MCA PI and the DV PIV (1 and 0 weeks). Finally, the UA PI began to sum anomalies 5 weeks before delivery, while the MCA and DV did it at 3 and 1 weeks before the pregnancy ended. CONCLUSIONS: In early-onset SGA fetuses, Doppler progression tends to follow a predictable order, with sequential changes in the umbilical, cerebral and DV impedances

    Computing probabilistic solutions of the Bernoulli random differential equation

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    [EN] The random variable transformation technique is a powerful method to determine the probabilistic solution for random differential equations represented by the first probability density function of the solution stochastic process. In this paper, that technique is applied to construct a closed form expression of the solution for the Bernoulli random differential equation. In order to account for the general scenario, all the input parameters (coefficients and initial condition) are assumed to be absolutely continuous random variables with an arbitrary joint probability density function. The analysis is split into two cases for which an illustrative example is provided. Finally, a fish weight growth model is considered to illustrate the usefulness of the theoretical results previously established using real data.This work has been partially supported by the Ministerio de Economía y Competitividad grant MTM2013-41765-P. Ana Navarro Quiles acknowledges the doctorate scholarship granted by Programa de Ayudas de Investigación y Desarrollo (PAID), Universitat PolitÚcnica de ValÚncia. Contratos Predoctorales UPV 2014- Subprograma 1.Casabån, M.; Cortés, J.; Navarro-Quiles, A.; Romero, J.; Roselló, M.; Villanueva Micó, RJ. (2017). Computing probabilistic solutions of the Bernoulli random differential equation. Journal of Computational and Applied Mathematics. 309:396-407. https://doi.org/10.1016/j.cam.2016.02.034S39640730

    Estimation of neutron-equivalent dose in organs of patients undergoing radiotherapy by the use of a novel online digital detector.

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    Neutron peripheral contamination in patients undergoing high-energy photon radiotherapy is considered as a risk factor for secondary cancer induction. Organ-specific neutron-equivalent dose estimation is therefore essential for a reasonable assessment of these associated risks. This work aimed to develop a method to estimate neutron-equivalent doses in multiple organs of radiotherapy patients. The method involved the convolution, at 16 reference points in an anthropomorphic phantom, of the normalized Monte Carlo neutron fluence energy spectra with the kerma and energy-dependent radiation weighting factor. This was then scaled with the total neutron fluence measured with passive detectors, at the same reference points, in order to obtain the equivalent doses in organs. The latter were correlated with the readings of a neutron digital detector located inside the treatment room during phantom irradiation. This digital detector, designed and developed by our group, integrates the thermal neutron fluence. The correlation model, applied to the digital detector readings during patient irradiation, enables the online estimation of neutron-equivalent doses in organs. The model takes into account the specific irradiation site, the field parameters (energy, field size, angle incidence, etc) and the installation (linac and bunker geometry). This method, which is suitable for routine clinical use, will help to systematically generate the dosimetric data essential for the improvement of current risk-estimation models

    Multidisciplinary consensus on screening for, diagnosis and management of fetal growth restriction in the Netherlands

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    Screening for, diagnosis and management of intrauterine growth restriction (IUGR) is often performed in multidisciplinary collaboration. However, variation in screening methods, diagnosis and management of IUGR may lead to confusion. In the Netherlands two monodisciplinary guidelines on IUGR do not fully align. To facilitate effective collaboration between different professionals in perinatal care, we undertook a Delphi study with uniform recommendations as our primary result, focusing on issues that are not aligned or for which specifications are lacking in the current guidelines. We conducted a Delphi study in three rounds. A purposively sampled selection of 56 panellists participated: 27 representing midwife-led care and 29 obstetrician-led care. Consensus was defined as agreement between the professional groups on the same answer and among at least 70% of the panellists within groups. Per round 51 or 52 (91% - 93%) panellists responded. This has led to consensus on 27 issues, leading to four consensus based recommendations on screening for IUGR in midwife-led care and eight consensus based recommendations on diagnosis and eight on management in obstetrician-led care. The multidisciplinary project group decided on four additional recommendations as no consensus was reached by the panel. No recommendations could be made about induction of labour versus expectant monitoring, nor about the choice for a primary caesarean section. We reached consensus on recommendations for care for IUGR within a multidisciplinary panel. These will be implemented in a study on the effectiveness and cost-effectiveness of routine third trimester ultrasound for monitoring fetal growth. Research is needed to evaluate the effects of implementation of these recommendations on perinatal outcomes. NTR436
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