Technical Feasibility Study of Ultrasound Muscle Imaging in Antenatal Ultrasound

The objective of the study is to evaluate the performance of muscle ultrasound sections on antenatal ultrasound between 21-24 amenorrhea weeks for the screening of muscle atrophy, in a sample of low-risk and high-risk pregnancies of congenital multiple arthrogryposis

Inclusion Criteria: * Any pregnant woman consulting in one of the two obstetric gynecology departments in connection with the CPDPN (Multidisciplinary Prenatal Diagnostic Centers) of the University hospitals of Lyon or Grenoble. * Mono-embryonic pregnancy. * Gestational ages retained on the first dating ultrasound or the 1st trimester ultrasound between 21-24 amenorrhea weeks. * For women at "high risk": diagnosis during ultrasound of the 1st, 2nd, or 3rd trimesters, of an abnormality of position / deformation of one or more joints, and / or an abnormality of fetal movements on screening ultrasound or interrogation (population group at "high risk of AMC"). * Regulatory criteria: adults, affiliated to a social security scheme, having signed a consent Exclusion Criteria: * Multiple pregnancies, and / or non-progressive . * Obese women (BMI \> 30 in early pregnancy) * Subject in a period of exclusion from another study * Subject under administrative or judicial supervision * Subject who cannot be contacted in case of emergency