Obstetric care in arthrogryposis multiplex congenita

Authors


* Dr J. C. R. Hardwick, Glasgow Royal Maternity Hospital, Rottenrow, Glasgow G4 0NA, UK.

Arthrogryposis multiplex congenita describes the presence at birth of fixed joint contractures. We present the obstetric care of a woman with arthrogyposis multiplex congenita.

Case report

This 27 year old woman attended the antenatal clinic nine weeks into her first pregnancy.

She herself had been delivered normally at term, arthrogryposis multiplex congenita being diagnosed at birth. Between the ages of 6 weeks and 17 years, she had undergone 12 orthopaedic operations to release contractures of her feet, knees, hips and left elbow. She had been asthmatic since childhood and took regular doses of inhaled steroids and β agonists. She was a non-smoker. At the age of 26, she had undergone laparotomy to remove bilateral benign ovarian teratomas. On this occasion, fibre optic intubation was required because of her skeletal abnormalities.

On examination, she was 1.21 m tall, spinal involvement of her arthrogyposis having produced a severe kyphoscoliosis with minimal neck extension. Movement in her arms was impaired by abnormally shaped scapulae. She walked with sticks and had a ‘swing-through’ gait, having no mobility in her legs. Examination of her cardiovascular system was normal.

Antenatal screening for trisomy 21 and neural tube defects was discussed and declined, as was any additional testing for arthrogryposis. A thrombophilia screen was negative. She was referred for advice to a tertiary referral centre. Prophylaxis against venous thromboembolism was recommended and she was started on dalteparin 20 mg/day subcutaneously at the end of the first trimester.

At 16 weeks of gestation, worsening breathlessness at rest necessitated admission to hospital. Peak expiratory flow rates were normal and investigations including chest radiography showed no evidence of infection. Examination revealed the uterine fundus to be at the xiphisternum due to her short stature and spinal deformity. An ultrasound scan showed a normal pregnancy. The options for treatment, including termination of the pregnancy, were discussed. Her dosage of inhaled β agonist and steroid was increased and chest physiotherapy started. Advice was given to adopt a more upright sleeping position. Her symptoms improved and after counselling she elected to continue with the pregnancy.

By 29 weeks of gestation, her breathlessness had increased markedly and elective preterm delivery was planned. Antenatal corticosteroids were given and a caesarean section was performed at 30 weeks of gestation.

Dalteparin was withheld prior to surgery. General anaesthesia was planned due to expected difficulties with regional anaesthesia; however, as with her previous intubation, some difficulty was anticipated. Local anaesthesia was provided with lignocaine nasal spray, nebulisers and local infiltration to the crinoid. An ‘awake’ fibre optic intubation was performed and general anaesthesia was induced. She delivered a 1300 g baby girl in good condition, the caesarean section being uncomplicated.

Her recovery was straightforward and she was able to walk with crutches within 48 hours. Dalteparin was continued for six weeks. Her daughter thrived well in the special care baby unit and was discharged from hospital after six weeks.

Discussion

Arthrogryposis multiplex congenita was first described in 1905 and affects 1 in 3000 births. Little is published about the care of women with arthrogryposis in pregnancy1. There are many causes2, which are summarised in Table 1. The common pathway to joint deformity is fetal akinesia. Joint contractures form in utero with short tendons and fibrous tissue formation around the joint preventing further movement. The diagnosis of underlying conditions may require nerve conduction studies, electromyography, computed tomography or magnetic resonance imaging of the joints and the central nervous system, muscle biopsy or chromosomal analysis.

Table 1.  Causes of arthrogryposis multiplex congenita.
NeuropathicFunctional or structural abnormality of the central or peripheral nervous system (e.g. neural tube defects; spinal muscular atrophy)
Muscle abnormalitiesmuscular dystrophies
mitochondrial disorders
Connective tissue disordersmetatropic dwarfism, diastrophic dysplasia
Space limitationstwins, fibroids
Intrauterine vascular compromiseantepartum haemorrhage, failed termination
Maternal diseasediabetes mellitus, myasthenia gravis, multiple sclerosis
Maternal drugscurare, alcohol, phenytoin, drugs of abuse

Arthrogryposis multiplex congenita may be classified by the pattern of involvement of the joints, amyoplasia being the most common form comprising one-third of cases. In this form, the limbs are affected symmetrically and in 84% of cases all four limbs are affected3. This best describes our patient's condition.

Arthrogryposis is usually sporadic. Our patient's sister was also affected; however half-siblings were not, suggesting an autosomal recessive disorder in this case. No genetic counselling has taken place before her pregnancy and was declined early in pregnancy.

Most cases of arthrogryposis are diagnosed at birth. An antenatal history of decreased fetal movement may be suggestive of the condition. Ultrasonography may detect arthrogryposis in the second and third trimesters, the limbs showing decreased movement or abnormal posture. If other anomalies coexist, it may be diagnosed earlier4–6.

Most women with this condition may expect a normal lifespan and have expectations of childbearing. People with arthrogryposis have higher than average intelligence, are well-motivated and the majority manage to walk7. The disabilities associated with this condition provide specific challenges to the obstetrician.

The risk of thromboembolism in these women is theoretically greater than in normal pregnancy, due to several factors. Already poor mobility may decrease further as pregnancy progresses, due to the symptoms associated with pregnancy (in our case breathlessness). Skeletal deformity makes operative delivery likely and this is associated with an increased risk of venous thromboembolism. Prophylaxis against venous thromboembolism should be considered in women with arthrogryposis multiplex congenita and should be continued after operative delivery, in line with the recommendations of the RCOG8. We continued prophylaxis for six weeks.

Arthrogryposis may be associated with decreased respiratory reserve and this may be further diminished by advancing pregnancy, especially as spinal deformity can greatly decrease the available space within the abdomen for uterine enlargement. Diaphragmatic function may therefore be affected earlier in pregnancy than expected. The woman in our case report had reversible airways disease, but peak expiratory flow rates suggested that this was stable. Decreased space within the abdomen may have a detrimental effect on fetal growth although in this case fetal growth; in our case, however, fetal growth was normal.

Maternal symptoms may force elective preterm delivery. The timing of elective preterm delivery is especially challenging when tests for fetal wellbeing are normal and the need for delivery is due to a chronic maternal condition. Women with arthrogryposis will usually have had numerous operations under general anaesthetic in childhood. Deformities of the upper spine and neck make standard endotracheal intubation difficult and alternative procedures may be necessary, as in this case. The additional risks of general anaesthesia for operative delivery must be weighed against the chance of successful regional anaesthesia. Use of continuous spinal anaesthetic has been reported9. Involvement of obstetricians, anaesthetists and paediatricians is the key to a successful outcome of pregnancy in this condition.

Useful addresses

The Arthrogryposis Group, 1, The Oaks, Gillingham, Dorset SP8 4SW, UK, or http://members.aol.com/taguk, http://members.aol.com/amcchat/amcinfo.htm and http://sonnet.com/avenues/.

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