Change in quantitative human chorionic gonadotropin after manual vacuum aspiration in women with pregnancy of unknown location

Objective

To determine whether the change in human chorionic gonadotropin after manual vacuum aspiration is predictive of an early abnormal intrauterine pregnancy in women with pregnancy of unknown location.

Study Design

This is a prospective cohort study of 23 clinically stable patients with an early abnormal pregnancy who had abnormally rising human chorionic gonadotropins and absence of sonographic evidence of an intrauterine pregnancy or ectopic pregnancy. The change in human chorionic gonadotropin within 24 hours after manual vacuum aspiration was compared with the pathologic diagnosis and the ultimate clinical diagnosis.

Results

Ten patients had ≥ 50% decrease (mean, 74%; range, 58-80%) in human chorionic gonadotropin after manual vacuum aspiration with confirmed chorionic villi on pathology results. Two patients had a > 50% drop in human chorionic gonadotropin but absence of chorionic villi, clinically consistent with complete spontaneous abortion. The remaining 10 patients who had either rising or < 50% decrease in human chorionic gonadotropin post manual vacuum aspiration all had no chorionic villi on pathology results. The sensitivity, specificity, positive predictive value, and negative predictive value of a ≥ 50% decrease in human chorionic gonadotropin after manual vacuum aspiration in predicting an abnormal intrauterine pregnancy were 92% (95% confidence interval [CI], 0.62-0.99), 100% (95% CI, 0.62-1.0), 100% (95% CI, 0.70-1.0), and 90% (95% CI, 0.54-0.99), respectively.

Conclusion

A ≥ 50% decrease in human chorionic gonadotropin within 24 hours after manual vacuum aspiration is predictive of an abnormal intrauterine pregnancy, thereby excluding an ectopic pregnancy and expediting the management of women with pregnancy of unknown location.

Key words: ectopic pregnancy, human chorionic gonadotropin, manual vacuum aspiration, miscarriage, pregnancy of unknown location