RT Book, Section A1 Yeomans, Edward R. A1 Hoffman, Barbara L. A1 Gilstrap III, Larry C. A1 Cunningham, F. Gary SR Print(0) ID 1138212670 T1 Ectopic Pregnancy T2 Cunningham and Gilstrap's Operative Obstetrics, 3e YR 2017 FD 2017 PB McGraw-Hill Education PP New York, NY SN 9780071849067 LK obgyn.mhmedical.com/content.aspx?aid=1138212670 RD 2024/03/28 AB An ectopic or extrauterine pregnancy is one in which the blastocyst implants anywhere other than the endometrial lining of the uterine cavity. As such, they account for 1 to 2 percent of reported pregnancies in the United States (Zane, 2002). With the advent of a sensitive and specific radioimmunoassay for the β-subunit of human chorionic gonadotropin (β-hCG), combined with high-resolution transvaginal sonography (TVS), the initial presentation of a woman with an ectopic pregnancy is seldom as life threatening as in the past. Nevertheless, ectopic pregnancies remain an important cause of morbidity and mortality in the first trimester of pregnancy in the United States.