Béatrice Blondel

Bio: Béatrice Blondel is an academic researcher from University of Paris. The author has contributed to research in topics: Population & Pregnancy. The author has an hindex of 51, co-authored 178 publications receiving 8089 citations. Previous affiliations of Béatrice Blondel include Pierre-and-Marie-Curie University & French Institute of Health and Medical Research.

A New and Improved Population-Based Canadian Reference for Birth Weight for Gestational Age

Abstract: Background. Existing fetal growth references all suffer from 1 or more major methodologic problems, including errors in reported gestational age, biologically implausible birth weight for gestational age, insufficient sample sizes at low gestational age, single-hospital or other non-population–based samples, and inadequate statistical modeling techniques. Methods. We used the newly developed Canadian national linked file of singleton births and infant deaths for births between 1994 and 1996, for which gestational age is largely based on early ultrasound estimates. Assuming a normal distribution for birth weight at each gestational age, we used the expectation-maximization algorithm to exclude infants with gestational ages that were more consistent with 40-week births than with the observed gestational age. Distributions of birth weight at the corrected gestational ages were then statistically smoothed. Results. The resulting male and female curves provide smooth and biologically plausible means, standard deviations, and percentile cutoffs for defining small- and large-for-gestational-age births. Large-for-gestational age cutoffs (90th percentile) at low gestational ages are considerably lower than those of existing references, whereas small-for-gestational-age cutoffs (10th percentile) postterm are higher. For example, compared with the current World Health Organization reference from California (Williams et al, 1982) and a recently proposed US national reference (Alexander et al, 1996), the 90th percentiles for singleton males at 30 weeks are 1837 versus 2159 and 2710 g. The corresponding 10th percentiles at 42 weeks are 3233 versus 3086 and 2998 g. Conclusions. This new sex-specific, population-based reference should improve clinical assessment of growth in individual newborns, population-based surveillance of geographic and temporal trends in birth weight for gestational age, and evaluation of clinical or public health interventions to enhance fetal growth. fetal growth, birth weight, gestational age, preterm birth, postterm birth.

Trends in perinatal health in France from 1995 to 2010. Results from the French National Perinatal Surveys

Abstract: OBJECTIVE: To study trends in the main indicators of health, medical practices and risk factors in France. POPULATION AND METHOD: We collected data from samples of all births in France during one week in 1995 (n=13318), 1998 (n=13718), 2003 (n=14737) and 2010 (n=14903) and have compared them. RESULTS: Between 1995 and 2010, maternal age and body mass index increased steadily, but tobacco use decreased. In 2010, 39.4% of pregnant women had a visit with a midwife in a maternity unit, versus 26.6% in 2003. Deliveries occurred in large public hospitals more and more frequently. The increase in caesarean sections was no longer significant between 2003 and 2010. In general, medical decisions during pregnancy and delivery were closer to professional recommendations in 2010 than in earlier years. Live births before 37 weeks increased steadily from 5.4% in 1995 to 6.6% in 2010, but the proportion of birth weights below 2500g or the 10th percentile stopped increasing after 2003. CONCLUSION: Routine national perinatal surveys highlight major trends in maternal characteristics, obstetric practices, organisation of services, and perinatal health.

La santé périnatale en France métropolitaine de 1995 à 2003

Abstract: Journal de Gynecologie Obstetrique et Biologie de la Reproduction - Vol. 35 - N° 4 - p. 373-387

The worldwide incidence of preterm birth: a systematic review of maternal mortality and morbidity

Abstract: Resumen Incidencia mundial de parto prematuro: revision sistematica de la morbilidad y mortalidad maternas Objetivo Analizar las tasas de prematuridad a nivel mundial para evaluar la incidencia de este problema de salud publica, determinar la distribucion regional de los partos prematuros y profundizar en el conocimiento de las actuales estrategias de evaluacion.Metodos Los datos utilizados sobre las tasas de prematuridad a nivel mundial se extrajeron a lo largo de una revision sistematica anterior de datos publicados e ineditos sobre la mortalidad y morbilidad maternas notificados entre 1997 y 2002. Esos datos se complementaron mediante una busqueda que abarco el periodo 2003–2007. Las tasas de prematuridad de los paises sin datos se estimaron mediante modelos de regresion multiple especificos para cada region.Resultados Estimamos que en 2005 se registraron 12,9 millones de partos prematuros, lo que representa el 9,6% de todos los nacimientos a nivel mundial. Aproximadamente 11 millones (85%) de ellos se concentraron en Africa y Asia, mientras que en Europa y America del Norte (excluido Mexico) se registraron 0,5 millones en cada caso, y en America Latina y el Caribe, 0,9 millones. Las tasas mas elevadas de prematuridad se dieron en Africa y America del Norte (11,9% y 10,6% de todos los nacimientos, respectivamente), y las mas bajas en Europa (6,2%).Conclusion El parto prematuro es un problema de salud perinatal importante en todo el mundo. Los paises en desarrollo, especialmente de Africa y Asia meridional, son los que sufren la carga mas alta en terminos absolutos, pero en America del Norte tambien se observa una tasa elevada. Es necesario comprender mejor las causas de la prematuridad y obtener estimaciones mas precisas de la incidencia de ese problema en cada pais si se desea mejorar el acceso a una atencion obstetrica y neonatal eficaz.

A systematic review and meta-analysis to revise the Fenton growth chart for preterm infants

Abstract: The aim of this study was to revise the 2003 Fenton Preterm Growth Chart, specifically to: a) harmonize the preterm growth chart with the new World Health Organization (WHO) Growth Standard, b) smooth the data between the preterm and WHO estimates, informed by the Preterm Multicentre Growth (PreM Growth) study while maintaining data integrity from 22 to 36 and at 50 weeks, and to c) re-scale the chart x-axis to actual age (rather than completed weeks) to support growth monitoring. Systematic review, meta-analysis, and growth chart development. We systematically searched published and unpublished literature to find population-based preterm size at birth measurement (weight, length, and/or head circumference) references, from developed countries with: Corrected gestational ages through infant assessment and/or statistical correction; Data percentiles as low as 24 weeks gestational age or lower; Sample with greater than 500 infants less than 30 weeks. Growth curves for males and females were produced using cubic splines to 50 weeks post menstrual age. LMS parameters (skew, median, and standard deviation) were calculated. Six large population-based surveys of size at preterm birth representing 3,986,456 births (34,639 births < 30 weeks) from countries Germany, United States, Italy, Australia, Scotland, and Canada were combined in meta-analyses. Smooth growth chart curves were developed, while ensuring close agreement with the data between 24 and 36 weeks and at 50 weeks. The revised sex-specific actual-age growth charts are based on the recommended growth goal for preterm infants, the fetus, followed by the term infant. These preterm growth charts, with the disjunction between these datasets smoothing informed by the international PreM Growth study, may support an improved transition of preterm infant growth monitoring to the WHO growth charts.