Transabdominal and transvaginal endosonography: evaluation of the cervix and lower uterine segment in pregnancy.

The clinical value of conventional transabdominal and transvaginal sonography (endosonography) for the evaluation of the cervix and lower uterine segment between 14 and 36 weeks' gestation was evaluated in 20 unselected obstetric patients. Sonographic evaluation of the cervix and lower uterine segment was adequately depicted in 76% with the transabdominal technique compared to 83% with the transvaginal approach. According to set guidelines, these preliminary results suggest that the transvaginal technique may be superior in obtaining an adequate evaluation of the lower uterine segment and cervix and may offer an advantage of not depending on a fully distended bladder for evaluation.