1. Department of Gynecology and Obstetrics, Jagiellonian University, Krakow, Poland,
2. Ultrasound Group Practice “dobreusg,” Krakow, Poland,
3. Center for Prenatal Diagnostics, Opole, Poland,
4. Institut für Pränatalen Ultraschall GmbH, Salzburg, Austria,
5. Medical Center Semedica, Krakow, Poland, and
6. St. Lucas Obstetric Center, Czestochowa, Poland