Restrictive lung disease

Interstitial lung disease

Restrictive lung disease appears reasonably well tolerated in preg­nancy as the lungs have relatively more reserve than the heart (38). Many women with restrictive lung disease and markedly reduced FVC due to conditions such as kyphoscoliosis, neuromuscular dis­ease, and parenchymal lung disease have successful pregnancy out­comes.

Figure 25.2 Mechanically ventilated woman with H1N1 pneumonitis. Note bilateral airspace disease, bilateral chest tubes for barotrauma, elevated diaphragms, and lead shielding of abdomen.

Reduced diffusing capacity may cause difficulty in meeting the increased oxygen consumption requirements of pregnancy. Associated pulmonary hypertension carries significant risks. Interstitial lung disease is encountered most commonly in preg­nancy as a manifestation of connective tissue disease (CTD) or sarcoid (discussed earlier). It is the most common pulmonary manifestation of connective tissue disease. It may be seen as a feature of rheumatoid arthritis, scleroderma, systemic lupus er­ythematosus, polymyositis, and Sjogren syndrome (40). High- resolution lung CT (which may safely be performed in pregnancy) is used to evaluate the extent and subtype of disease (Figure 25.3). Management of the acute presentation is usually with high-dose intravenous pulsed methyl prednisolone and management of the chronic disease is immunosuppression with steroids, azathioprine, cyclophosphamide, methotrexate, or biologicals such as rituximab. Immunosuppression, usually with prednisolone or azathioprine, should be continued in pregnancy. Mycophenolate mofetil, metho­trexate, and rituximab are usually avoided in pregnancy but cyclo­phosphamide can be used in the second and third trimester for severe disease (41).