Curvas de crecimiento pre- y posnatales para la identificación de los recién nacidos de bajo peso con resultados neonatales adversos

Abstract

Fetal growth restriction (FGR) is a condition in which fetuses do not reach their growth potential. However, small for gestational age fetuses (SGA) are constitutionally small, without a known event which justifies a smaller size. The percentage of SGA will depend on the characteristics of the population, being around 7-10% in developed countries and exceed 30% in developing countries1. FGR is a less frequent complication, present in 3-5% of all pregnancies.FGR is defined prenatally as an estimated fetal weight (EFW) below the 3rd percentile or as an EFW < 10th percentile plus any fetal-placental Doppler abnormality. These may consist of an increase in placental resistance to the flow of the umbilical arteries (UA) or a phenomenon of hemodynamic redistribution as a consequence of fetal adaptation to adverse environments such as those caused by hypoxia, maternal malnutrition or poor placental perfusion. Postnatal identification of FGR is performed by verifying a birth weight below the 3rd percentile, obtained in the first 24 hours of life.Prenatally, any fetus with a PFE between the 3rd and 9th percentiles without hemodynamic alterations in the Doppler study is classified as SGA. Postnatally, any newborn with a birth weight between these same percentiles is also considered as SGA, regardless of the fetal Doppler...