Causes may involve Physical limitation of movement (eg, due to uterine malformations, multiple gestations, or oligohydramnios) causing fetal akinesia / hypokinesia syndrome (Pena-Shokeir syndrome), frequently associated with pulmonary hypoplasia Maternal disorders (eg, multiple sclerosis, impaired uterine vascularity) Genetic disorders affecting the fetus (eg, neuropathies; myopathies, including muscular dystrophies; connective tissue abnormalities; impaired fetal vascularity; anterior horn cell disease) More than 35 specific genetic disorders (eg, spinal muscular atrophy type I, trisomy 18) have been linked to AMC.