Serial hCG and progesterone levels to predict early pregnancy outcomes in pregnancies of uncertain viability: A prospective study

Abstract

Objective: To assess the value of serial hCG and progesterone serum level in the diagnosis of early pregnancy viability.

Methods: It was a prospective cohort study. Women with a pregnancy of uncertain viability (PUV), defined as the presence of an intra-uterine embryo with a crown-rump length <7mm with no cardiac activity or an intra-uterine gestational sac size <25mm with no visible embryonic structure in a transvaginal ultrasound scan (TVS) were eligible. The diagnosis value of serial plasmatic hCG levels on the first day and 48h after as well as the initial progesterone level were evaluated to diagnose pregnancy viability. Pregnancy viability was assessed by TVS 7 to 14days after inclusion.

Results: The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of an hCG H48/H0 ratio increase <11% to diagnose an early pregnancy loss were 70.6%, 100%, 100% and 85.3%, respectively. The sensitivity, specificity, PPV and NPV of a 6.2ng/ml progesterone level to diagnose an early pregnancy loss were 20%, 100%, 100% and 65.2%, respectively. The sensitivity, specificity, PPV and NPV of an hCG H48/H0 ratio increase >75% to diagnose a viable pregnancy were 100%, 31%, 45.9% and 100%, respectively. hCG H48/H0 ratio increase <11% was associated with early pregnancy loss in 100% of the cases. hCG H48/H0 ratio increase >75% was associated with 100% of viable pregnancies in 100% of the cases.

Conclusion: Serial hCG levels alone permitted an early viability diagnosis within 48h for 41.1% of patients with PUV instead of 7 to 14days with TVS.

Keywords: First trimester; Miscarriage; Progesterone; Serial hCG; Viability.