When a pregnancy ends tragically due to fatal abnormalities of the fetus, it is important to understand the medical reasons behind the event. This evaluation can help predict the risk of reoccurrence in future pregnancies. In the case of fetal akinesia deformation sequence (FADS), the fetus may have been affected by a disrupting injury or unavoidable maldevelopment.
An article in the June issue of the journal Pediatric and Developmental Pathology discusses underlying causes of FADS. The term encompasses several overlapping disorders that begin with decreased fetal movement and involve degeneration of the brain and spinal cord, joint contractures, and craniofacial anomalies.
Researchers hypothesized that there is an often unrecognized pattern in FADS—a combination of neural and muscular pathology. Autopsy cases of fetuses at 20 to 23 weeks' gestational age were examined. Out of 18 cases of FADS, seven showed delayed skeletal muscle maturation that would suggest only a muscular disease. However, when four of these cases were more closely examined, they revealed polymicrogyria (a brain malformation) and evidence of hypoxic/ischemic injury—a lack of oxygen or blood—to the central nervous system.
Polymicrogyria in FADS cases is often attributed only to malformation of the developing brain. A few cases have been described that associate polymicrogyria with central nervous system hypoxic/ischemic injury without the inclusion of a delay in skeletal muscle maturation. Given the four cases found in this study, the authors believe there is a need for complete neuropathologic examinations that can help determine the frequency of hypoxic/ischemic injury in FADS.
Pediatric and Developmental Pathology