Prevalence:

• 1 in 3,000 births.

Ultrasound diagnosis:

• Malposition of the limbs and limited fetal movements, resulting from contractures in ≥2 joints.
• Onset of arthrogryposis varies: from 12 to 30 weeks’ gestation.
• The condition is commonly associated with polyhydramnios (>25 weeks' gestation), narrow chest, micrognathia and nuchal edema (or increased nuchal translucency at 11-13 weeks).
• Fixed abnormal contractures of muscles can be:
  • Regional: only the lower or upper limbs are affected. If the lower region is affected, the legs are hyperextended and crossed. If the upper region is affected, the arms are flexed lying on each side of the thorax.
  • Generalized: all muscles are affected as in fetal akinesia deformation sequence.

Associated abnormalities:

• Chromosomal abnormalities: a few cases have trisomy 8 or 18.
• More than 150 genetic syndromes are associated with arthrogryposis. The most common are:
  • Fetal akinesia deformation sequence:  group of abnormalities of different causes characterized by decreased fetal movements, multiple joint contractures, fetal growth restriction, facial anomalies, pulmonary hypoplasia and occasionally hydrops. 
  • Cerebro-oculo-facio-skeletal syndrome: autosomal recessive; severely reduced muscle tone, distinctive facial features (low-set ears, microphthalmia, micrognathia) and abnormalities of the skull, limbs, heart, and kidneys.
  • Neu-Laxova syndrome: autosomal recessive; hypertelorism, microcephaly, agenesis of corpus calosum, contractures in the upper and lower limbs, fetal growth restriction.
  • Multiple pterygium syndrome: autosomal recessive; cystic hygromas, contractures in all joints,  microcephaly and micrognathia.

Investigations:

• Detailed ultrasound examination.
• Invasive testing for karyotyping and array.
• Detailed medical history should be obtained concerning infection, fever or hypothermia and exposure to teratogens such as phenytoin and ethanol.
• Myotonic dystrophy or myastenia gravis should be ruled out.

Follow up:

• Ultrasound scans every 2-3 weeks to monitor growth, movements in all joints and amniotic fluid volume. Amniodrainage may be necessary if there is polyhydramnios and cervical shortening.

Delivery:

• Place: hospital with facilities for neonatal intensive care.
• Delivery by elective cesarean section due to possible complications resulting from abnormal fetal position and lack of flexibility of the limbs.

Prognosis:

• If multiple organs are affected there is high mortality within the first months of life.
• If only limbs are affected, surgery and physiotherapy aim to achieve the maximum function for each involved joint.

Recurrence:

• Depends on the underlying condition.
• Distal arthrogryposis: 50%.