Occult abnormal pregnancies after first post–embryo transfer serum beta-human chorionic gonadotropin levels of 1.0–5.0 mIU/mL

• Published in: Fertility and sterility Vol. 105; no. 4; pp. 938 - 945.e1
• Main Authors: Maslow, Bat-Sheva L., M.D, Bartolucci, Alison, M.S, Sueldo, Carolina, M.D, Engmann, Lawrence, M.D, Benadiva, Claudio, M.D, Nulsen, John C., M.D
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-04-2016
• Subjects: Adult; Biomarkers - blood; Case-Control Studies; Chorionic Gonadotropin, beta Subunit, Human - blood; Cohort Studies; Ectopic pregnancy; Embryo Transfer - trends; Female; Follow-Up Studies; Humans; Internal Medicine; in vitro fertilization; Obstetrics and Gynecology; Pregnancy; Pregnancy Complications - blood; Pregnancy Complications - diagnosis; Pregnancy Complications - epidemiology; Pregnancy, Ectopic - blood; Pregnancy, Ectopic - diagnosis; Pregnancy, Ectopic - epidemiology; Retrospective Studies; serum β-hCG; Ectopic pregnancy; in vitro fertilization; serum β-hCG
• ISSN: 0015-0282; 1556-5653
• DOI: 10.1016/j.fertnstert.2015.11.049

Objective To assess the occult pregnancy rate after “negative” first post−embryo transfer (ET) serum β-hCG results. Design Two-part retrospective cohort study and nested case series. Setting University-based fertility center. Patient(s) A total of 1,571 negative first post-ET serum β-hCG results were included in the study; 1,326 results (primary cohort, June 2009–December 2013) were initially reported as <5 mIU/mL and 245 results (secondary cohort, January 2014–March 2015) were reported as discrete values from 1.0 to 5.0 mIU/mL. Intervention(s) None. Main Outcome Measure(s) Rates of occult pregnancy, ectopic pregnancy, and complications after negative first post-ET serum β-hCG results. Result(s) A total of 88.8% (1,178/1,326) of the negative first post-ET results reported as <5 were actually <1.0 mIU/mL. Occult pregnancy was incidentally identified in 1.2% (12/1,041) of subjects with follow-up. Six had ectopic pregnancies, and seven experienced serious complications; 11 (91.7%) of the 12 occult pregnancies had a first post-ET serum β-hCG level of 1.0–5.0 mIU/mL and 1 (8.3%) <1.0 mIU/mL. All pregnancies with serious complications had initial β-hCG levels of 1.0–5.0 mIU/mL. Of the 245 results reported as discreet values, occult pregnancies were diagnosed in 5.5% (9/163) of subjects with follow-up. One had an ectopic pregnancy, which was treated with methotrexate. There were no serious complications in the secondary cohort. Conclusion(s) The majority of negative first post-ET serum β-hCG levels are <1.0 mIU/mL. Results from 1.0 to 5.0 mIU/mL may fail to exclude abnormal pregnancy and are associated with poor outcomes compared with β-hCG levels <1.0 mIU/mL. Serial serum β-hCG may be warranted in this population.