Study of Placental Vascularization Using Contrast Ultrasound

Inclusion Criteria: * Adult woman (age ≥18 years), * Gestational age between 16 GW + 0 days and 38 GW + 6 days, * Singleton pregnancy, * Whose request of a medical termination of pregnancy (IMG) has been formulated and accepted in a written form by the Centre Pluridisciplinaire de Diagnostic Prénatal (CPDPN) of the Centre Hospitalier Régional Universaitaire (CHRU) de Nancy, * Affiliated to the social security system or benefit from such a system, * Having received full information and having signed an informed consent form. Criteria specific to patients in the "growth restriction" group: \- Severe growth restriction defined by an estimation of foetal weight below the 3rd percentile using ultrasound performed no more than 15 days prior to the IMG (the diagnosis must be established at the time of the request for IMG in routine care). Exclusion Criteria: * Person who do not speak French * Any medical condition contraindicating the administration of SonoVue, in particular: * Hypersensitivity to sulfur hexafluoride or to one of the other components of SonoVue® such as polyethylene glycol (PEG), * Women with recent acute coronary syndrome or unstable ischaemic heart disease, * Women with a right-to-left shunt, severe pulmonary arterial hypertension (pulmonary arterial pressure \> 90 mmHg), uncontrolled systemic hypertension and women suffering from respiratory distress syndrome. * Persons covered by articles L. 1121-5, L. 1121-7 and L1121-8 of the French Public Health Code: * Breast-feeding mother * Minor (not emancipated) * An adult subject to a legal protection (guardianship, curatorship, safeguard of justice) * An adult unable to give consent * Persons deprived of their liberty by a judicial or administrative decision, persons under psychiatric care by virtue of articles L. 3212-1 and L. 3213-1