[The use of ultrasonography in the prediction of first-trimester abortion]

The prediction of spontaneous abortion in the first trimester is made possible owing to the use of two diagnostic procedures: maternal assay of some biochemical parameters and ultrasonography. However, the diagnostic value of ultrasound is greater than the former procedure since it enables the embryo to be visualized directly, measuring crown-rump length (CRL), together with the gestational sac whose diameter can also be measured (DSG). The present study aimed to verify the prediction of abortion given by the ratio between DSG and CRL measured using ultrasound in the first trimester of pregnancy, namely with signs of embryonic vitality already present. A prospective longitudinal study was performed in a population of 59 pregnant women attending the Obstetric and Gynecology Clinic of Trieste University during the period between April 1990 and April 1991. On enrollment in the study all patients had a gestational age of 8 +/- 2 weeks of amenorrhea. A preliminary measurement of DSG and CRL (t0) was then obtained and these measurements were repeated after four weeks (t1). The data obtained were first compared to each other for the same time (DSG0/CRL0 and DSG1/CRL1) and the relationship between the two ratios was then calculated ((DSG1/CRL1)/(DSG0/CRL0)). This method provides a sensitive method of analysing variations in the ratio between the two measurements taken at different moments. Inferential statistical principles were then applied. At the end of the first trimester the evolution or otherwise of pregnancy was assessed by examining and separating two groups of women: those who had had spontaneous abortions and those who had continued their pregnancies.(ABSTRACT TRUNCATED AT 250 WORDS)