Correlation between a gene hypoxia score and umbilical artery pH levels sampled at birth. Gene hypoxia score is the sum of relative hypoxia inducible factor (Hif)1α, Hif2α, adrenomedullin (Adm) and lactate dehydrogenase A (LdhA) expression in maternal blood on the day of delivery. Samples were taken from the fetal growth restriction cohort. P = 0.008. Colors indicate umbilical artery waveform findings seen on the day of delivery: Blue = Raised systolic/diastolic ratio, Green = Absent end diastolic flow, Red = Reversed end diastolic flow.