Human Chorionic Gonadotropin (βhCG)

Human chorionic gonadotropin (hCG) is detected in urine as early as one week before an expected menstrual period.

It usually remains elevated for several weeks after a pregnancy has ended.

Serum hCG is definitive.

hCG is typically lower in ectopic pregnancies than intra-uterine pregnancies for gestational age and in ectopics rises more slowly. This is however not diagnostic [11,12].

Levels above 1000-2000 IU/L in the absence of sonographic signs of pregnancy is considered presumptive evidence of an ectopic pregnancy.

The gynaecologists manage some patients with known ectopic pregnancy expectantly. Usually falling hCG levels suggest spontaneous involution. It is still possible for these ectopic pregnancies to rupture, and a high index of suspicion should be maintained when these women present to the ED with abdominal pain and/or vaginal bleeding [13].