[Visualization of the fetus in early pregnancy with transvaginal sonography].

The aim of this prospective study is to define in early pregnancy the time and percentage of visualization of embryo-fetal structures and organs. 820 patients at high risk for fetal genetic anomalies and/or malformations were scanned by high resolution transvaginal probe between 10 and 16 weeks' gestational age. Criteria for exclusion were: fetal malformations, multiple pregnancies and loss of pregnancy. We determined percentage of visualization in the different weeks of: orbits, face, cerebellum, cisterna magna, cardiac chambers, abdomen, diaphragm, stomach, kidneys and bladder. The percentage of visualization of fetal organs and structures investigated increased with gestational age and at 13 weeks ranged from 80% to 100%. With the introduction of high-frequency transvaginal probes in early pregnancy embryo-fetal structures and organs can be imaged and studied in great detail and more accurately identified than with traditional abdominal ultrasound, up to 4 weeks earlier. Another important advantage is the fact that some fetal malformations can be detected earlier.