Figure 1.

Cumulative incidence graphs

(A) Preterm delivery of a small for gestational age infant (birthweight below the tenth customised percentile) following 28 weeks of gestational age measurement by screening status. Screen positivity was defined as estimated fetal weight below the tenth percentile for gestational age, combined with a sFLT1/PlGF ratio greater than 5·78. Number at risk 3934 screen negatives and 47 screen positives. (B) Delivery of a small for gestational age infant plus a complication following 36 weeks of gestational age measurement by screening status. Screen positivity was defined as an estimated fetal weight below the tenth percentile for gestational age, combined with sFLT1/PlGF ratio more than 38. Number at risk 3645 screen negatives and 102 screen positives. Small for gestational age was defined as birthweight below the tenth population-based percentile and a complication was defined as one or more of the following: non-anomalous perinatal death, any neonatal morbidity, or maternal pre-eclampsia. The number at risk increases before it decreases because the majority of women had their scan and blood sample taken after 28 weeks and zero days (A) or after 36 weeks and zero days (B). sFLT1=soluble fms-like tyrosine kinase 1. PlGF=placental growth factor.