Objective: To describe the incidence, predisposing conditions, and inciting factors culminating in pulmonary edema in the pregnant patient.
Methods: A review of 62,917 consecutive pregnancies delivered at our institution from January 1, 1989 to June 1, 1999 was undertaken for the diagnosis of pulmonary edema. Each chart was reviewed for maternal demographics, admission diagnoses, medication use, gestational age at diagnosis, fluid balance, coexisting maternal illness, tocolytic use, evidence of preeclampsia, and diagnostic criteria. After careful review of the records, the most likely cause of pulmonary edema was assigned.
Results: Fifty-one women (0.08%) were diagnosed with acute pulmonary edema during pregnancy or in the postpartum period. The mean patient age at the time of diagnosis was 27.6 +/- 6.4 years. The mean gestational age at the time of diagnosis was 31.5 +/- 6.8 weeks. The diagnosis of pulmonary edema was made during the antepartum period in 24 patients (47%), the intrapartum period in seven (14%), and the postpartum period in 20 (39%). The most common attributable causes were tocolytic use (13 patients [25.5%]), cardiac disease (13 patients [25.5%]), fluid overload (11 patients [21.5%]), and preeclampsia (nine patients [18%]). Those with fluid overload identified as the likely etiology had a significantly greater mean positive fluid balance (6022 +/- 3340 mL). All patients whose pulmonary edema was secondary to tocolytic use received multiple simultaneous tocolytic agents; the most common combination was intravenous magnesium sulfate and subcutaneous terbutaline. Six of the 13 women with cardiac disease were found to have previously undiagnosed structural heart disease.
Conclusion: The most common causes of pulmonary edema are the use of tocolytic agents, underlying cardiac disease, fluid overload, and preeclampsia.