Background Management of suspected large for gestational age (LGA) fetuses remains unclear because the lack of accuracy of ultrasound estimated fetal weight. Objectives To assess the methodology of studies reporting 2D ultrasound assessment of fetal soft tissues with the aim of improving the screening of LGA fetuses. Search strategy This was a systematic review of observational studies. A search for relevant articles was performed in MEDLINE, EMBASE, CINAHL, Web of Science (from inception to 31 January 2022), and references of the retrieved articles. Two authors independently selected studies and assessed the risk of bias and extracted the data. Selection criteria Studies on fetal soft tissues measurements used alone or in combination to create a new estimated fetal weight (EFW) formula, to improve the screening for LGA fetuses. Data collection and analysis Studies were scored using a predefined set of independently agreed methodological criteria and an overall quality score was assigned for study design, statistical analysis, and reporting methods. Main results Thirty-two studies met the inclusion criteria (ten for a new EFW algorithm and twenty-two for an isolated parameter used as cut-off for LGA fetuses detection). The highest potential bias were noted in the following fields: sample size estimation, diabetes description, report of perinatal outcomes, number of measurements taken, and multicenter study. Only eight out of thirty-two studies scored over 70% in design quality. Conclusions There is a need for the standardization of methodologies for soft fetal tissues measurements and for the development of reference standards, which can be correctly interpreted and applied in clinical practice. We propose a set of suggestions for this purpose.