[Systematic echography in the first trimester of pregnancy]

The purpose of this prospective study was to ascertain the usefulness of routine first trimester ultrasonography in 872 consecutive patients. A high incidence of abnormalities was noted: 35% A significant discrepancy between ultrasonography and menstrual dating was frequently noted: in 24% of all patients, and in 14% of patients with optimum menstrual history. These data suggest that routine obstetric ultrasonography should be considered for all patients at the first trimester, and that ultrasonometry in this period is the gold standard to estimate the true gestational age.