Urinary β-core fragment as a predictor of abnormal pregnancy at 4–6 weeks’ gestation

Currently, transvaginal ultrasound and serial serum β-hCG measurements are used to differentiate normal versus abnormal gestations in the first trimester of pregnancy. These techniques have been found to be ineffective when the gestations are earlier than 6 weeks. This study was conducted to determine if urinary β-core fragment, the urine degradation product of β-hCG, could be used to distinguish normal from abnormal gestations between 4 and 6 weeks. Urine samples were obtained from 27 patients on initial presentation to the emergency room or outpatient settings with gestations at 4–6 weeks by sure last menstrual period. The urine was then frozen at ––40 °C and sent for β-core assay analysis. Eighteen women with normal intrauterine pregnancies and nine abnormal pregnancies, including ectopics and spontaneous abortions, were studied. Pearson correlations were performed with a p < 0.05 considered significant. In the normal gestations, there was a positive correlation between β-core fragment and gestational age at 4–6 weeks (r = 0.461, p < 0.05). This correlation was not evident in abnormal gestations (r = 0.360, p = 0.34). In early pregnancy, β-core fragment correlates positively with gestational age which is not apparent in abnormal counterparts. This finding suggests that urinary β-core fragment may be a promising marker to differentiate normal early pregnancies from abnormal gestations.