History of ultrasound in obstetrics and gynaecology from 1971 to 2021 on occasion of the 50 years anniversary of EFSUMB.

Diagnostic ultrasound in obstetrics and gynaecology has experienced a fantastic evolution during the past seven decades. Initial steps with A-mode technology were followed by B-mode and B-mode real-time imaging, then by Doppler and colour Doppler ultrasound, and finally by 3D/4D ultrasound. Other evolutionary steps were the development of high-resolution transabdominal and transvaginal transducers providing high quality images in the first, second and third trimesters of pregancy, as well as in gynaecology and breast imaging.The progression from two-dimensional (2D) to three-dimensional ultrasound (3D) and 3D real-time imaging (4D) has brought new options in displaying anatomical structures. In comparison with CT or MRI, it is not a static but functional technique, cheap and safe, and applicable at any time.