The screening of embryonic viability in early asymptomatic pregnancy by a single endosonographic scan associated with plasma human chorionic gonadotropin determination

Abstract

Our purpose was to assess, with a prospective study with random assignment of the day of the first evaluation, whether a single transvaginal ultrasonographic evaluation together with the determination of plasma hCG levels could be used to screen embryonic viability in early asymptomatic pregnancy. In 260 pregnant women observed from January 1991 to November 1993 with spontaneous pregnancies where the exact date of ovulation was known, a single transvaginal ultrasonographic 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 gestational sac below the 95% lower confidence limit of the viable pregnancy group. The sensitivity was 31%, with a specificity of 97%. 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.