Nouvelle formule de détermination de l'âge d'un foetus

International audienceThe methods utilised in anthropology for foetal age assessment are generally rather old, based on small samples and have never been tested on other samples than the one they were established on. In this study, we establish a formula on 344 foetuses of known age, and compare it with other age determination methods found in the scientific literature. Except our formula, the tested other methods do not give the limits of the prediction's confidence interval, and therefore do not take into account the total variability. Therefore, we demonstrate the necessity to establish formulas based on large samples and on a validated methodology.Les méthodes de détermination de l'âge foetal utilisées en anthropologie sont anciennes, établies sur de petits effectifs et n'ont pas été testées sur un échantillon différent de celui qui a servi à les établir. Dans cette étude, nous établissons une formule sur 344 foetus d'âges connus et la comparons avec d'autres déteminations proposées dans la littérature. Contrairement à notre formule, ces dernières ne proposent pas d'intervalles de confiance de leur prédiction et ne prennent donc pas correctement en compte la variabilité. Nous démontrons ainsi la nécessité d'établir de nouvelles équations sur la base d'un effectif aussi large que possible et reposant sur une méthodologie validée

Validation of a Radiographic Method to Establish<br />New Fetal Growth Standards: Radio-Anatomical<br />Correlation

International audienceIn forensic medicine, specialists might face difficultieswhen estimating age at death from fetal remains. Depending on the state of preservation, this age assessment is essentially based on the diaphyseal size of long bones. In a previous work, for the measurement of fetal femoral ossified shafts, we already established a simple and reliable method using a radiographic protocol. Since we previously stated that radiographic measurement values were closer to real anatomical size than ultrasonographic ones, in the present study we decided to check the importance of the difference between radiographic and anatomical measurements. Therefore, we dissected 30 pairs of fetal femurs and compared the difference between the two kinds of measurements (in percentages). This difference seemed to be slight (4.027%), but it was large enough to entail significantdifferences (p 0.001). In order to provide a correction factor for radiographic measurements, we established a linear regression formula, which was tested on another sample of 30 pairs of dissected femurs. As a consequence of the good results, we improved the linear regression using a powerful statistical tool: the bootstrap. Finally, we obtained a simple equation that allowed us to figure out the real anatomical size with an R2 of 99% and a mean relative difference of 0.153% (with a standard error of 0.252 mm, and therefore a 95% confidence interval with limits of 0.35 and 0.657 mm). This difference did not entail any significant differences(p 0.498), and therefore, we concluded that with the proposed correction, radiographic measurements can easily be used by forensic specialists in their daily tasks or to establish new growth standardsin order to best fit their population of interest

Prenatal prognosis of congenital diaphragmatic hernia using magnetic resonance imaging measurement of fetal lung volume

Objectives: To investigate the correlation between fetal lung volume (FLV), measured with magnetic resonance imaging (MRI), and postnatal mortality in newborns with prenatally diagnosed isolated congenital diaphragmatic hernia (CDH). Methods: In a 4-year prospective multicenter study, 77 fetuses with isolated CDH diagnosed between 20 and 33 weeks' gestation underwent fast spin-echo T2-weighted lung MRI. These MRI-FLV measurements were compared with a previously published normative curve obtained in 215 fetuses without thoracoabdominal malformations and with normal ultrasound biometric findings. FLV measurements were correlated with postnatal survival. The mean gestational age at MRI was 31.3 weeks. Results: The measured/expected FLV ratio was significantly lower in the newborns with CDH who died compared with those who survived (23.6 ± 12.2 vs. 36.1 ± 13.0, P < 0.001). When the ratio was below 25%, there was a significant decrease in postnatal survival (19% vs. 40.3%, P = 0.008). Survival was significantly lower for neonates when one lung could not be seen by fetal MRI compared with those fetuses with two visible lungs on MRI (17.9% vs. 62.1%, P < 0.001). Conclusion: In isolated CDH, FLV measurement by MRI is a good predictor of postnatal mortality due to pulmonary hypoplasia. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.SCOPUS: ar.jFLWINinfo:eu-repo/semantics/publishe