CAS

A congenital anomaly scan (CAS), sometimes called congenital anatomy scan or 20-week scan, is done in the second trimester, between 18 to 22 weeks. The International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) recommends that CAS ultrasound be performed as part of the routine prenatal care for pregnant all women.  Read more here: https://www.smartparenting.com.ph/pregnancy/health-nutrition/congenital-anomaly-scan-during-pregnancy-a00041-20180715