Evaluation of Fetoplacental Oxygenation With Functional MRI in Pregnant Women

Inclusion Criteria: * Major patient * Patient with a singleton pregnancy * Patient between 18 and 37 gestational weeks * Informed consent signed by the patient * Patient affiliated to a social security scheme (beneficiary or assignee) Specific criteria for patients with a eutrophic fetus * Patient with fetal eutrophic on sonographic fetal weight estimation Specific criteria for patients with an IUGR-fetus Patient with a fetus presenting intra-uterine growth restriction diagnosed by ultrasound (\<5th percentile). Exclusion Criteria: * Patient with the usual contra-indications for MRI * Patient with an abdominal circumference\> 125 cm * Patient with a multiple pregnancy * Patient with placenta accreta or percreta * Patient with a pregnancy after long history of infertility and medically assisted procreation