THE SCREENING OF EMBRYONIC VIABILITY IN EARLY ASYMPTOMATIC PREGNANCY BY A SINGLE ENDOSONOGRAPHIC SCAN ASSOCIATED WITH PLASMA HUMAN CHORIONIC-GONADOTROPIN DETERMINATION

Purpose: Our purpose was to assess, with a prospective study with rand om assignment of the day of the first evaluation, whether a single tra nsvaginal ultrasonographic evaluation together with the determination of plasma hCG levels could be used to screen embryonic viability in ea rly asymptomatic pregnancy. Methods: In 260 pregnant women observed fr om January 1991 to November 1993 with spontaneous pregnancies where th e exact date of ovulation was known, a single transvaginal ultrasonogr aphic measurement of gestational sac with determination of plasma hCG levels, transformed to their natural logarithm (lnhCG), was performed. An abnormal result was defined as a value of lnhCG per mean gestation al sac below the 95% lower confidence limit of the viable pregnancy gr oup. Results: The sensitivity was 31%, with a specificity of 97%. Conc lusion: The study demonstrates that this method has a poor predictive capacity to distinguish viable pregnancy from nonviable pregnancy with a kappa value less than 0.4.