First trimester fetal anatomy study and identification of major anomalies using 10 standardized scans.

Objective: to validate the use of the first trimester scan not just as a screening tool for chromosomal anomalies, but also as a method to identify the major anatomic anomalies using 10 standardized scans.

Methods: five years of prospective study analyzing the fetal anatomy of 5924 patients with a singleton pregnancy during the first trimester screening for chromosomopathies. A check list of 10 predetermined scans had been used. The follow up consisted of two more scans in the second and third trimester, according to the local protocol, and a final evaluation of neonatal outcome at birth.

Results: in the 5924 examined patients, the percentage of major malformations is 0.74%, most of all discovered in the first trimester (47.7%). The Detection Rate for the malformations related to the nervous system is about 50% and for the malformations of the abdomen, heart and skeleton is slightly lower (43.5%).

Conclusions: first trimester ultrasound using 10 standardized scans is a valid screening method for chromosomopathies and also an effective method to identify many of the major fetal anato - mical anomalies.