Inclusion Criteria:  > 18 years old Singleton pregnancy Date of conception evaluated by ultrasound < 14 WG Consulting in one of the 3 participating centers for IUGR Estimated fetal weight < 5th centile (according to Hadlock 3 et CFEF) Between 22+0 WG et 34+6 WG  Exclusion Criteria:  Major birth defect diagnosed at time of inclusion Abnormality of caryotype known at time of inclusion Confirmed preeclampsia at time of inclusion