Clinical Summary

A 32-year-old woman presented for consultation at 25 weeks and 5 days gestation following findings of fetal akinesia. The pregnancy was previously uncomplicated, with no known maternal illnesses, rashes, or exposures. This is the mother’s third pregnancy. The couple has two healthy children. Family history is notable for a 20-week stillbirth in the maternal parents and early-onset dementia in the paternal mother.

A 20 week ultrasound identified a 5 mm right choroid plexus cyst. Serial follow-up imaging revealed progressive limb anomalies consistent with arthrogryposis: atypical alignment of the right pedal digits, persistently clenched hands bilaterally, and bilateral rocker bottom feet with widely spaced digits. By 24 weeks and 5 days, imaging confirmed fetal thighs in a crossed position, femur lengths at the 4th percentile, and polyhydramnios. Non-invasive prenatal testing (NIPT) indicated a low risk for common trisomies and microdeletions. Amniocentesis results showed a normal chromosomal microarray. Given the severity of the abnormalities, the couple elected for termination of pregnancy.  

Discussion points

1. What are the major histological findings?
2. What is the differential diagnosis?
3. What ancillary testing would be most informative?