F5 and fetal growth restriction: A study in 2002 performed on 65 women whose antepartum course was complicated by mid-trimester IUGR (22-26 weeks) inferred that the prevalence of FVL and PTG mutations was significantly higher among cases compared to controls, that is, 35% versus 3.8% (p < 0.001) for FVL and 15.4 versus 2.0 for PTG (p < 0.05) [73].