In an asymptomatic cohort, serum pregnancyassociated proteinA (PAPPA) levels among women destined to miscarry were 14%of those seen with ongoing pregnancies. Levels were as low 3 weeks before diagnosis as on the day of diagnosis, suggesting that PAPPA levels might predict future miscarriage. In an asymptomatic cohort, serum pregnancyassociated proteinA (PAPPA) levels among women destined to miscarry were 14% of those seen with existing pregnancies. Levels were as low 3 weeks before diagnosis as on the day of diagnosis, suggesting that PAPP-A levels might predict future miscarriage.