LUMIERE on the PLACENTA

Study Overview
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Brief Summary
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The frequency of IUGR is between 3 and 10% of births. The etiologies and mechanisms of IUGR are multiple. The placental insufficiency, that is the defect of perfusion, is, however, the principal mechanism, far in front of other maternal or fetal causes. This placental insufficiency is also now recognized as an essential risk factor for cardiovascular and metabolic diseases, such as diabetes, in adulthood. The interest in understanding in utero development is thus further increased by the short-, medium- and long-term consequences of placental dysfunction. However, there are few ways to evaluate uteroplacental vascularization in vivo. MRI is an imaging technique used routinely in the exploration of the fetus in addition to ultrasound. Its safety on the fetus and the mother is largely demonstrated at 1.5T. There are also MRI sequences used daily in the clinic to evaluate perfusion and organ structure in children and adults (brain, kidney, heart, etc.). Their application for evaluation of perfusion and placental structure, although still confined to research, is very promising. The investigator's team has extensive experience, in animals or in children, in the use of these sequences that could be used to evaluate placental function in vivo. The ASL (Arterial Spin Labeling) in particular is the most encouraging functional imaging technique because it allows today to measure an organ blood flow quantitatively and without injection of contrast medium.

Detailed Description
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The inclusion will take place at the earliest at 20 weeks after the completion of the standard morphological ultrasound of the 2nd trimester (carried out at 20-24SA) and at the latest at 35 SA, within the framework of one of the 2 clinical subgroups of patients considered (high risk and low risk). The objectives of this study will be achieved by the prospective setting up of a LUMIERE cohort on PLACENTA.

Official Title
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LUMIERE on the PLACENTA : A Study on the Added Value of MRI

Conditions
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Pregnancy

Intervention / Treatment
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* Other: Fetal MRI


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Singleton pregnancy without fetal malformation seen on ultrasound. Group 1: High risk IUGR patients EPF<10th perc or PA<10th perc and Doppler ombilical IP> 95th percentile, EPF or PA<3th perc reference curves from Collège Français d'Echographie Fœtale, between 20 et 34 GW, Group 2: Low risk IUGR patients • EPF et PA>20th perc reference curves from Collège Français d'Echographie Fœtale, between 20 et 34 GW Exclusion Criteria: - Contraindication to MRI Impossible subsequent follow up Maternal status contraindicates continuation of pregnancy Participation in another search Protected patient

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Group 1: High risk IUGR patients<br>EPF<10th perc or PA<10th perc and Doppler ombilical IP> 95th percentile, EPF or PA<3th perc (reference curves from Collège Français d'Echographie Fœtale, between 20 et 34 GW), | Other: Fetal MRI<br>* The MRI examination added by this research, without injection or sedation, induces no risk for the mother as for the fetus(es)<br>|
| Group 2: Low risk IUGR patients<br>EPF et PA>20th perc (reference curves from Collège Français d'Echographie Fœtale, between 20 et 34 GW) | Other: Fetal MRI<br>* The MRI examination added by this research, without injection or sedation, induces no risk for the mother as for the fetus(es)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in placental blood flow as seen in vascular IUGR | 25% reduction in overall placental perfusion measured ASL with IUGR (defined as <3th perc birth weight) versus controls (birth weight> 10th perc) | From inclusion to end of neonatal period (max 25 weeks) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Placental response to maternal oxygenation (BOLD) | BOLD effect | From inclusion to end of neonatal period (max 25 weeks) | 
| structural changes of the placenta | Diffusion coefficient (ADC) | From inclusion to end of neonatal period (max 25 weeks) | 
| structural changes of the placenta | T2 * mapping | From inclusion to end of neonatal period (max 25 weeks) | 
| Measurement of placental volume | Placental segmentation | From inclusion to end of neonatal period (max 25 weeks) | 
| Measurement of IUGR by fetal segmentation (MRI), | Fetal volume | From inclusion to end of neonatal period (max 25 weeks) | 
| evaluation of brain resonance | BOLD effect, - ADC coefficient and IVIM parameters by variation of T2 * relaxation time | From inclusion to end of neonatal period (max 25 weeks) | 
| evaluation of kidney resonance | BOLD effect, - ADC coefficient and IVIM parameters by variation of T2 * relaxation time | From inclusion to end of neonatal period (max 25 weeks) | 
| evaluation of liver resonance | BOLD effect, - ADC coefficient and IVIM parameters by variation of T2 * relaxation time | From inclusion to end of neonatal period (max 25 weeks) | 
| Reproducibility of the examination analysis | Correlations between microcirculatory parameters in utero, fetal weight at MRI and birth weight | After study completion, an average of one year | 
| Uterine arteries | Measurement of blood flow in the uterine arteries by MRI 4D FLOW (in development) and Doppler (US) (feasibility study) | From inclusion to end of neonatal period (max 25 weeks) | 
| Acceptability of the examination for the patient: questionnaire | Will be assessed by a questionnaire given to pregnant women after the MRI, | at IRM examination | 
| Acceptability of the examination for the patient: Likert scale | will be assessed once by a Likert scale: 4 points Likert (poor, average, good, very good) | at IRM examination | 
| Specific Absorption Rate for each type of sequence | SAR measurement (Specific Absorption Rate) | From inclusion to end of neonatal period (max 25 weeks) |