Do all women with indeterminate pregnancies need a formal ultrasound before discharge from the emergency department?

OBJECTIVE: The identification of ectopic pregnancy is the primary concern for pregnant patients with an indeterminate ultrasound (an empty uterus or gestational sac). The absence of free fluid and adnexal masses by ultrasound combined with the absence of ectopic risk factors are used to place women in a "low-risk" category. We believe that women in a "low-risk" category with a β-human chorionic gonadotropin (β-hCG) below 3,000 mIU/mL can be discharged with only an emergency department (ED) ultrasound, provided there is 48 to 72 hours obstetric follow-up.

METHODS: Follow-up encounters from August 2010 to March 2011 were reviewed. The inclusion criteria were women who only received an ED performed indeterminate ultrasound and an acute follow-up appointment with concern for ectopic pregnancy.

RESULTS: Forty-nine women met inclusion criteria. Twenty-nine women (59.2%, 95% CI: 45.4%-73%) had a spontaneous abortion; 18 women (36.7%, 95% CI: 23.2%-50.2%) had a normal pregnancy, and 2 women (4.1%, 95% CI: 1.5%-9.7%) had an ectopic pregnancy. Both ectopic pregnancies had no risk factors with β-hCG values of 96 and 197 mIU/mL.

CONCLUSION: This study suggests that low-risk indeterminate pregnancies by an ED ultrasound and β-hCG level <3,000 mIU/mL can be safely discharged without formal ultrasonography provided a 48 to 72 hours follow-up with an obstetrician.