Purpose: 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.
Methods: 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.
Results: The sensitivity was 31%, with a specificity of 97%.
Conclusion: 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.