Temporal refinement does not affect predicted human chorionic gonadotropin rise in early pregnancy

Data verification and improved temporal precision suggested a faster hCG increase in early intrauterine gestation than previously demonstrated. Because laboratory variation and temporal imprecision are common, these data demonstrate that current modeling of the expected rise of hCG in a normal gestation is valid and appropriately conservative in the determination of a nonviable gestation. No change in the minimal threshold for potential viability is recommended.