As both PAPP-A and sFlt-1 may predict increased risk for preeclampsia, in this study we explore the relationship of 1st trimester PAPP-A levels, which are obtained routinely for clinical care, with serial levels of sFlt-1, a widely accepted marker of preeclampsia in research, and test the hypothesis that 1st trimester PAPP-A correlates with serial sFlt-1 levels throughout pregnancy. The gene discussed is PAPPA; the disease is preeclampsia.