Inclusion Criteria:  over 18 years old, treated in the DDIANE fetal medicine centre at the Bordeaux University Hospital, having a fetus with IUGR diagnosis below the 3rd percentile (after reference medical ultrasound), from 16 weeks of amenorrhea or more, accepting an Invasive Prenatal Diagnosis by amniocentesis with array comparative genomic hybridization  Exclusion Criteria:  Childbearing women who:  do not accept a non-invasive prenatal diagnosis (amniocentesis) have a fetus with non-isolated IUGR (associated with other ultrasound signs) do not consent to participate in the research protocol