hCG in Ectopic PregnancyVISCONTI, KEVIN MD; ZITE, NIKKI MD, MPHClinical Obstetrics & Gynecology: June 2012 - Volume 55 - Issue 2 - p 410–417 doi: 10.1097/GRF.0b013e31825109dc Ectopic Pregnancy Abstract Author Information Ectopic pregnancies remain an important cause of morbidity and mortality in women of reproductive age. Management of these pregnancies has changed dramatically over the years. Human chorionic gonadotropin (hCG) is a glycoprotein hormone composed of 2 dissimilar subunits, alpha and beta, joined non-covalently. The free beta-subunit is the principal immuno-reactive agent in pregnancy serum samples. Improved diagnostic methods using hCG levels in combination with transvaginal ultrasound have lead to earlier detection rates, subsequent treatment and a reduction in mortality resulting from ectopic pregnancies. This chapter will describe current trends in ectopic pregnancy diagnosis based on hCG levels. Department of Obstetrics and Gynecology, University of Tennessee Graduate School of Medicine, Knoxville, Tennessee The authors declare that they have nothing to disclose. Correspondence: Nikki Zite, MD, Department of Obstetrics and Gynecology, University of Tennessee Graduate School of Medicine, Knoxville, TN. E-mail: firstname.lastname@example.org © 2012 Lippincott Williams & Wilkins, Inc.