[The cervix at term--an ultrasonographic study].

Transvaginal sonography with a 5 MHZ probe was used to measure the cervical length, width and the internal os. We examined 37 Primiparae (group 1) and 36 Multiparae (group 2) in the 40th and 41st gestational week vagino-sonographically. All pregnancies were uncomplicated. For comparison between the datas of shortening and thickening of cervix the students t-test showed a significance of p less than 0.05. We registered vagino-sonographically that under painless uterine contractions the cervix shortened with an increase of thickness, while the internal os was constant and opened at least. A reformation of cervix in the relaxation phases was seen.