Prenatal diagnosis of fetal akinesia deformation sequence (FADS): a study of 79 consecutive cases.

Abstract

Fetal akinesia deformation sequence (FADS) is a clinically and genetically heterogenous disorder. In this study, the different sonographic abnormalities are described in a larger number of affected fetuses. This retrospective study included 79 cases of suspected FADS observed in our tertiary referral center between January 2001 and February 2015. Electronic stored reports and images of the examination were reviewed as well as autopsy reports and pediatric charts. In the study population (mean gestational age 23+4weeks) consanguinity, multiple miscarriages or positive family history were present in 31.6% of cases. Abnormalities of the facial profile (58.3%) and ankle joint (83.6%) were detected in the majority of cases. Contractures variably involved knee-, ankle-, wrist- and elbow joint and fingers with no distinct patterns. Additional malformations, most commonly of the brain, were found in 44.3% of cases. Diagnosis before 20weeks was associated with nuchal edema in 62.5 and hydrops in 31.3%. In fetuses evaluated later than 24weeks, IUGR, increased amniotic fluid or thorax hypoplasia were diagnosed, in 31, 58.8 and 37.9%, respectively. Termination of pregnancy was requested in 86.1%, 11 (13.9%) children were live born. No underlying genetic cause was established, but in one asymptomatic mother myasthenia gravis was revealed. Fetal akinesia presents with heterogeneous sonographic findings, mostly affecting the profile, elbow-, knee-, ankle joint, wrists and fingers; in most of cases of sporadic nature. Whereas hydrops fetalis and nuchal edema were earlier signs, thorax hypoplasia, polyhydramnios and IUGR were found later in pregnancy.