Risk factors for acute pulmonary edema in preterm delivery.

OBJECTIVE

To determine the risk factors for pulmonary edema in women with preterm delivery.

STUDY DESIGN

This was a case-controlled study of 52 (6.7%) cases with and 722 (93.3%) cases without pulmonary edema in a cohort of women who delivered between 24 and 33 weeks. Univariate and logistic regression analysis were used as indicated.

RESULTS

Of subjects with pulmonary edema 98% received tocolytics while 94% had antenatal corticosteroid therapy versus 50% and 40% in controls. Significant positive associations of pulmonary edema only on univariate analysis were multiple pregnancy, earlier presenting gestational age, positive maternal cultures, small for gestational age while significant negative associations were indicated by preterm delivery and premature rupture of membranes. Independent predictors of pulmonary edema on logistic regression analysis were spontaneous preterm labor (odds ratio {OR}=10.9, p=0.026; 95% CI 1.3, 90), tocolytic therapy (OR=4.3, p=0.000; 95% CI 2.3, 8.4) especially magnesium sulfate and nifedipine, antenatal corticosteroid therapy (OR=2.3, p=0.002; 95% CI 1.3, 4), chorioamnionitis (OR=2.7, p=0.028; 95% CI 1.1, 6.5), blood product transfusion (OR=2.3, p=0.038; 95% CI 2.2, 8.4) and tobacco use (OR=2.5, p=0.016; 95% CI 1.2, 5.4).

CONCLUSIONS

In mothers delivering prematurely, pulmonary edema is more likely with spontaneous preterm labor, smokers, infections or those receiving blood transfusions. It occurs almost exclusively in patients treated with antenatal corticosteroids and tocolytic medication.