[Current status of vaginal ultrasound. Part II: Obstetrical diagnosis, new aspects and future perspectives].

In obstetrics the main advantage of transvaginal sonography is in the first trimester. It is possible to diagnose normal or abnormal pregnancy or ectopic pregnancy earlier and more exactly than with transabdominal ultrasound. Furthermore different foetal malformations can be detected within the first trimester. Applications in the second and third trimesters are the evaluation of the cervix to detect cervical incompetence or the evaluation of the lower placental segment in case of placenta praevia. In contrast to transvaginal ultrasound the assessment of the foetus in the second and third trimesters remains a domain of abdominal ultrasound. However, transvaginal scanning can be a useful adjunct in cases where the foetal head is deeply engaged or for the visualisation of a foetal organ that is close to the vaginal probe. Transvaginal colour Doppler as well as transvaginal 3 D-volume scanning represent new aspects of transvaginal sonography in obstetrics and gynaecology. These techniques will provide progress especially in tumour diagnosis in the lower pelvis in the future.