Rapid measurement of urinary pregnanediol glucuronide to diagnose ectopic pregnancy

We investigated the ability of a single, random, urinary pregnanediol-3α-glucuronide level to differentiate early intrauterine from ectopic pregnancy. Thirty-four patients with intrauterine gestations were compared with 60 patients with ectopic pregnancies. Urinary pregnanediol-3α-glucuronide was measured by radioimmunoassay and enzyme immunoassay. Compared with intrauterine gestations, results demonstrate that urinary pregnanediol-3α-glucuronide is significantly depressed in ectopic pregnancies: 24.5 ± 2.2 versus 4.8 ± 0.7 μg/ml (p = 0.0001). Urinary pregnanediol-3α-glucuronide levels obtained by conventional radioimmunoassay correlated closely with values measured in minutes with enzyme immunoassay (r = 0.95, p = 0.0001), and with serum progesterone (r = 0.74, p = 0.0001). Urinary pregnanediol-3α-glucuronide measured by enzyme immunoassay exhibited predictive values for detecting ectopic gestations comparable with random serum progesterone or serum β-human chorionic gonadotropin values. We conclude that ectopic gestations demonstrate a reduced level of urinary pregnanediol-3α-glucuronide (5560 cases) detectable with a rapid enzyme immunoassay, which makes this assay a practical screening test in early pregnancy.