Prediction of Pregnancy Outcomes Through hCG Alone in Women Presenting with Vaginal Bleeding in Early Pregnancy

Abstract

Bleeding in early pregnancy is routinely investigated using human chorionic gonadotropin (hCG) levels and ultrasonography. The initial hCG level, combined with clinical suspicion for ectopic pregnancy, is used to determine if an ultrasound is necessary, and thus the timing of initial and final diagnoses. However, the prediction accuracy of initial hCG values for such cases has not been fully explored. The objective of this study is to evaluate the prediction capabilities of initial hCG values for outcomes in stable patients <14 weeks pregnant with vaginal bleeding. There are four specific aims: for women with the first ultrasound ≤72 hours of hCG measurement 1) determine range of initial hCG values that can predict a diagnosis (e.g. early pregnancy failure, viable pregnancy, or potential ectopic pregnancy) from first ultrasound. 2) Evaluate prediction accuracy of initial hCG values for each pregnancy outcome for initial and final diagnoses. 3) Assess if initial hCG levels can be used to predict time from first ultrasound to final diagnosis for pregnancy of unknown location and intrauterine pregnancy of uncertain viability; for all women 4) determine prediction accuracy of initial hCG values for each final diagnosis. A retrospective study of Early Pregnancy Assessment Clinic patients between 2006 and present will be performed. Receiver operating characteristic analyses will be performed for Specific Aims #1, 2, and 4, while survival analyses will be applied for Aim #3. These results would aid health care providers in counselling patients on the likelihood of various pregnancy outcomes using their hCG values alone.