Optimization of Fetal Ultrasound Examination for the Presence of Congenital Malformations of the Brain in Pregnant Women in the Second Trimester

Ultrasound examination (US) remains the primary method of prenatal diagnosis of congenital fetal anomalies due to its safety, accessibility, and informativeness. The second trimester of pregnancy (18-24 weeks) is the optimal period for detecting most fetal brain anomalies, as by this time the main processes of CNS structure formation are completed while maintaining adequate visualization due to the relatively small size of the fetal head and low ossification of the skull bones.