Correlación entre la Estimación Ecográfica del Peso Fetal a Partir de la Semana 37 de Gestación y el Peso al Nacer: Una Revisión Sistemática

Ultrasound estimation of fetal weight from 37 weeks of gestation is a key component of obstetric practice for assessing fetal growth and supporting perinatal decision-making. However, the accuracy of the correlation between estimated fetal weight and actual birth weight may be influenced by maternal, technical, and temporal factors. The aim of this systematic review was to analyze the correlation between ultrasound-estimated fetal weight performed from 37 weeks of gestation and birth weight, as well as to identify the main factors affecting its precision. A systematic review of observational studies published in English and Spanish over the last ten years was conducted following PRISMA 2020 guidelines. The search was carried out in PubMed/MEDLINE, Cochrane Library, Embase, Scopus, Elsevier/ScienceDirect, and LILACS. Studies assessing ultrasound fetal weight estimation from 37 weeks of gestation and its comparison with birth weight were included. The findings indicate a generally high correlation between ultrasound-estimated fetal weight and birth weight, particularly when the examination is performed shortly before delivery. Nevertheless, maternal obesity, gestational diabetes, operator experience, and ultrasound equipment quality were associated with increased estimation error. In conclusion, ultrasound estimation of fetal weight from 37 weeks of gestation is a useful clinical tool, whose interpretation should be contextualized to optimize obstetric decision-making.