Pregnancy with cytochrome oxidase-deficient mitochondrial myopathy.

BACKGROUND: Cytochrome oxidase-deficient mitochondrial myopathies represent a heterogeneous group of muscle disorders. Physical stress can cause life-threatening risks related to rhabdomyolysis or respiratory compromise. CASE: A 21-year-old primigravida with cytochrome C oxidase-deficient mitochondrial myopathy who presented for obstetric care at 8 weeks' gestation complained of muscle fatigue and spasm after exertion. The increased metabolic demands of pregnancy led to worsening pain, muscle fatigue, and ultimately complete immobility. CONCLUSION: Cytochrome oxidase-deficient mitochondrial myopathies are rare but serious complications of pregnancy.