Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine
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Comparative Study
Ectopic pregnancy. Diagnosis by sonography correlated with quantitative HCG levels.
Pelvic sonograms were correlated with simultaneous human chorionic gonadotropin (HCG) determinations in 150 women with early intrauterine pregnancy (N = 76) and ectopic pregnancy (N = 74). Of the 76 patients with intrauterine pregnancy (IUP), 55 had HCG levels exceeding 1,800 mIU/ml (Second International Standard), and in each case a gestational sac was identified. ⋯ Although six patients (8%) with ectopic pregnancy demonstrated a "pseudogestational sac," no case was confused with a true gestational sac. We conclude that, when the HCG level exceeds 1,800 mIU/ml, an intrauterine gestational sac is normally detected and its absence is evidence for an ectopic pregnancy.