Hello Thanks for your query. Arthrogryposis, also known as arthrogryposis multiplex congenita (AMC), is a rare congenital disorder that is characterized by multiple joint contractures and can include muscle weakness and fibrosis. The life span for an individual with arthrogryposis is usually normal, but may be altered by heart defects or central nervous system problems. To complicate things, the disease has a spectrum of sub - classifications, and depending on the classification, the severity is decided. Just amniocentesis cannot identify the exact disorder, unless muscle/nerve biopsy was also performed. Exact diagnosis is only possible after birth otherwise. The risk of miscarriage ranges from 1 in 400 to 1 in 200, although it increases when amniocentesis is performed later on in pregnancy, after the normal range of 14 - 20 weeks. Take care. Hope a fetal autopsy was done after the delivery of the baby, as it affects your future pregnancies also.