Development of a nomogram for fetal Evans Index

This study aims to investigate the fetal Evans Index and establish a nomogram for fetuses without any additional fetal anomalies detected during the prenatal period. We conducted our research at Ankara City Hospital, including 894 patients who were admitted and evaluated between gestational weeks 16-40. These patients had no fetal anomalies detected in subsequent gestational weeks. Descriptive data, such as age, gravidity, parity, and body mass index (BMI), were recorded. Gestational week and Evans Index (mean, median, standard deviation, minimum, maximum, and percentile) were also documented. The Evans index was calculated as the ratio between the maximal width of the frontal horns and the maximal width of the inner diameter of the cranium. We evaluated 894 fetuses in pregnant women had no fetal anomalies detected throughout the pregnancy. The evaluation took place at different gestational weeks, and a nomogram for the Evans Index was created. It is relevant for clinicians and researchers to be aware of the range of fetal Evans Index values across different gestational weeks as a prognostic criterion.