Preterm labor and maternal hypoxia in patients with community-acquired pneumonia

We sought to determine if preterm labor is associated with the degree of maternal hypoxia in pregnant women with community-acquired pneumonia but no other maternal diseases.

We retrospectively reviewed the medical records of all antepartum patients admitted with a diagnosis of community-acquired pneumonia to an inner-city university hospital between 1983 and 1987. Included in this review were only the patients with radiologically confirmed diagnose of pneumonia and documented arterial blood gases on room air at the time of admission, but no other maternal diseases.

A total of 22 cases were identified. There was no maternal mortality, but there were 2 patients (9%) who developed respiratory failure requiring mechanical ventilation. Bacteremia with Streptococcus pneumoniae was documented in 1 patient (5%). Preterm labor complicated 5 cases (23%) and led to preterm delivery in 3 patients (14%). Terbutaline tocolysis was instituted in 3 patients, but was discontinued in 1 patient who was allowed to deliver because of her worsening condition. Preterm labor was associated with the WBC count on admission, usually > 18,000/mm3, but no statistically significant correlation with the severity of maternal hypoxia was noted. Five patients (23%) were incorrectly diagnosed at the time of admission, 4 with an initial diagnosis of pyelonephritis and 1 with an initial diagnosis of cholecystitis.

Community-acquired pneumonia in the antepartum period is responsible for significant maternal and fetal complications even in the absence of other maternal diseases. Preterm labor and delivery remain frequent, and tocolysis should be used cautiously. At the time of admission, the diagnosis may be difficult. The degree of maternal hypoxia on admission does not correlate with the presence of preterm labor.