Clinical Application of One-Step Diagnosis for Ectopic Pregnancy by HCG Ratio: Hemoperitoneum Versus Venous Serum

Suspected ectopic pregnancy (SEP) means a woman whose hemoperitoneum and pregnancy test are positive but the gestational sac is uncertain, which is finally diagnosed as an ectopic pregnancy (EP) or a hemoperitoneum with intrauterine pregnancy (hIUP). For emergency physicians, it is mostly important to differentiate EPs rapidly from hIUPs of which the vast majority can be managed without surgery. The combination of transvaginal ultrasound and serum HCG determination seem to be reliable for the early diagnosis of EP (Kaplan et al., 1996; Mol et al., 1998.). However, in most of the emergency rooms (especially on the night shift) in the general hospital, transvaginal ultrasound is often unavailable or instead of transabdominal ultrasound operated by a nonprofessional gynecologist in developing countries, which limits the prompt and accurate diagnosis of EP. Besides, the serial transvaignal ultrasound and HCG quantity result in a lot of workload for the gynecologist and additional medical costs for the patients (Condous et al., 2005.). A serum: cerebrospinal fluid (CSF) HCG ratio less than 40 is an accurate indication of the presence of brain metastases of gestational trophoblastic tumor, and may have considerable predictive value. However, false-negative serum: CSF HCG ratio (greater than 40) frequently occur in patients with proven brain deposits, and the cerebrospinal fluid puncture or lumbar puncture is difficult to perform for the gynecologist (Bakri et al., 2000.). Magnetic resonance imaging head scan, hence, is now preferred as the most sensitive and safe technology available for brain metastases of gestational trophoblastic tumor. Culdocentesis is the transvaginal passage of a needle into the posterior cul-de-sac in order to determine whether free blood is present in the abdomen. It is a simple procedure to determine whether there is intraperitoneal hemorrhage. It has been used less frequently in recent years because many gynecologists think it useless for the diagnosis of EP. In the light of the idea that serum: CSF HCG ratio is indication of the presence of brain metastases, making use of the simple operation of culdocentesis, we have proved that HCG ratio of hemoperitoneum versus venous serum (Rp/v-HCG) of EPs is apparently different from that of hIUPs (Wang, et al., 2010.). Hence, in order to provide a single-visit method for predicting EP from SEP, we want to prospectively further assess the diagnostic value of the Rp/v-HCG for early EP. Furthermore, we want to discuss the availability of Rp/v-HCG for rare EP such as abdominal pregnancy et cetera.