Longitudinal sFlt-1/PlGF ratios during pregnancy by PAPP-A status and pregnancy diagnosis. sFlt-1/PlGF ratios varied significantly between the 4 groups and overall followed a U-shaped pattern, with the greatest differences observed at 8–10 weeks and 34–35 weeks. At 8–10 weeks, PE-LowPAPPA women had significantly lower sFlt-1/PlGF ratio compared with NlPreg-LowPAPPA (p = 0.03) and also compared with NlPreg-HighPAPPA (p = 0.0006). NlPreg-LowPAPPA women also had significantly lower sFlt-1/PlGF ratio compared with NlPreg-HighPAPPA women (p < 0.0001). By 34–35 weeks, however, PE-LowPAPPA women had the highest sFlt-1/PlGF ratio, and this was significantly higher than NlPreg-LowPAPPA (p = 0.03) and NlPreg-HighPAPPA (p = 0.04). At this time point, no differences were observed in sFlt-1/PlGF ratio between NlPreg-LowPAPPA and NlPreg-HighPAPPA women.