[Echography in the first pregnancy trimester has prognostic value].

Clinical and ultrasound data of 403 first-trimester pregnancies were collected prospectively. Consequences for determination of gestational age as well as the risk of spontaneous abortion were investigated. There was a clear relation between embryonal growth delay and the risk of spontaneous abortion: the risk of spontaneous abortion was significantly higher if the crown-rump length lagged 7 or more days behind the expected gestation time based on the duration of the amenorrhoea (16% versus 5.0%; p less than 0.01). It is important to know the exact duration of pregnancy, because a difference of one or two weeks can be critical in terms of survival or disability. 22.7% of the pregnant women who had a regular menstrual cycle before this pregnancy appeared to have an embryonal growth delay of seven days or more in relation to the reference curve. This illustrates the necessity of crown-rump length measurements in order to obtain accurate assessment of gestational age, which is fundamental in obstetric care.