The authors of the article on spontaneous abortion1 use the Advanced Life Support in Obstetrics syllabus3 to substantiate the statement that, “When transvaginal ultrasonography reveals an empty uterus and the quantitative serum hCG [human chorionic gonadotropin] level is greater than 1,800 mIU per mL (1,800 IU per L), an ectopic pregnancy should be considered.”1
However, the article on ectopic pregnancy2 refers to a previous AFP article4 on ectopic pregnancy to support the statement that, “ectopic pregnancy is suspected…if transvaginal ultrasonography does not show an intrauterine gestational sac and the patient’s beta-hCG level is 1,500 mIU per mL (1,500 IU per L) or greater.”2
Thank you for any clarification you can provide on the current standard for this critical management issue.
in reply:We appreciate the opportunity to clarify the issue regarding the beta-human chorionic gonadotropin (beta-hCG) level above which a gestational sac can be visualized consistently with transvaginal ultrasound. The beta-hCG level at which we can visualize a gestational sac has decreased over time with advances in ultrasound technology. The article by the Advanced Life Support in Obstetrics (ALSO) syllabus refers to an article published in 1986.1 The recent literature regarding evaluation for possible ectopic pregnancy is consistent in recommending that, at a beta-hCG level of 1,500 mIU per mL (1,500 IU per L) or greater, the gestational sac should be visualized with transvaginal ultrasound.2–6 Our diagnostic strategy reflects this recommendation.