Transperineal sonography in second trimester to term pregnancy and early labor.

We studied the diagnostic potential of transperineal sonography in 184 pregnant women from midtrimester to term pregnancies and at early labor. In 65 patients in false labor, we established cervical effacement and dilatation. We confirmed the clinical diagnosis of premature rupture of the membranes (PROM) in 27 cases and assessed the placental relationship with the internal cervical os in 20 patients. In 61 women in early labor we measured cervical dilatation, and in 11 patients we looked for details of fetal anatomy. Adequate diagnostic information was obtained in 180 cases (97%). Our results and data from the literature suggest that transperineal sonography is the imaging technique of choice in the situations we studied.