Cystic fibrosis (CF) is an autosomal recessive genetic disorder with a frequency of approximately 1 in 2000 births. It is primarily a disease of exocrine gland function. As a result of improved medical care, women with CF are increasingly reaching childbearing age and presenting in pregnancy. Pregnancy itself is not thought to increase mortality in women unless pre-pregnancy forced expiratory volume in 1 second (FEV1) is less than 50-60% of predicted, there is respiratory colonisation with Burkholderia cepacia, or she has pancreatic insufficiency. Women with CF will often need an increased level of medical care during and after pregnancy to maintain their clinical status. However, studies have shown that women with CF who become pregnant have a higher 10-year survival rate than those who do not, probably reflecting milder disease severity. Overall mortality has been reported as 5% within 2 years of pregnancy and 10-20% within 5-10 years.
Problems and special considerations
Depending on their pre-pregnant state, women with CF may tolerate the physiological changes of pregnancy poorly.
The main anaesthetic consideration is limited pulmonary reserve. These patients have tenacious secretions that can lead to hypoxaemia secondary to ventilation-perfusion mismatch, and they suffer multiple respiratory infections necessitating intravenous antibiotics. They often have hyperreactive airways, and there is an increased incidence of spontaneous pneumothorax. They may also develop bronchiectasis, for which regular postural drainage is required. Regional blockade may further impair respiratory function, especially if extensive.
Pulmonary hypertension with right heart failure may also occur; it carries with it a poor outcome for both mother and baby.
Diabetes, renal impairment and obstructive jaundice may occur.
Common gastrointestinal symptoms of pregnancy, such as reflux and vomiting, may be particularly prevalent.
Management options
The outcome of the pregnancy will depend on the woman’s nutritional status and the degree of pulmonary insufficiency, with more severe disease associated with an increased incidence of respiratory deterioration, preterm delivery and neonatal complications such as low birth weight and perinatal death. Respiratory function is best assessed by performing pulmonary function tests in the first and third trimesters. Careful cardiac assessment is also required to exclude the coexistence of right heart failure.
Vaginal delivery
Oxygenation should be optimal at all times, and continuous oxygen saturation monitoring with supplemental oxygen may be required. Stress and pain during labour will increase the respiratory demands, and it is thus important to reduce these. The respiratory depressant effect of drugs, and in particular opioids, should be considered. Mobility is important to facilitate postural drainage. Low-dose epidural analgesia is the management of choice in most cases in order to satisfy these conditions; the height of block should be monitored closely to reduce the risk of a block height above the T10 dermatome. Physiotherapy may be required after delivery to prevent chest infections, and an increased level of midwifery help with the new baby may be necessary.
Caesarean section
In addition to obstetric indications, caesarean section may also be required for worsening maternal respiratory function. Regional anaesthesia is recommended, although it may be difficult for women with severe respiratory impairment to lie flat. Care should be taken to avoid a high block, and an incremental technique (e.g. using combined spinal-epidural anaesthesia) may be best if impairment is already severe. If general anaesthesia is undertaken, bronchial secretions will need regular suction, particularly before extubation. Techniques to avoid bronchospasm (see Chapter 133, Asthma) and ventilatory strategies to avoid development of a pneumothorax should be employed. Postoperative analgesia is particularly important and is best provided by neuraxial opioids. During the recovery period, high-dependency care is essential and should include regular physiotherapy.
Key points
• Antenatal planning, with close liaison with the mother’s cystic fibrosis team, is essential.
• Maintenance of oxygenation should be given high priority at all times.
• Regional analgesia and anaesthesia are usually indicated, but care should be taken to avoid high blocks.
Further reading
Edenborough FP, Borgo G, Knoop C, et al.; European Cystic Fibrosis Society. Guidelines for the management of pregnancy in women with cystic fibrosis. J Cyst Fibres 2008; 7 (Suppl 1): S2-32.
Huffmyer JL, Littlewood KE, Nemergut EC. Perioperative management of the adult with cystic fibrosis. Anesth Analg 2009; 109: 1949-61.
McArdle J. Pregnancy in cystic fibrosis. Clin Chest Med 2011; 32: 111-20.