Anemia and Low Albumin Levels Are Associated with Severe Community-Acquired Pneumonia in Pregnancy: A Case-Control Study

Community-acquired pneumonia (CAP) is the most common form of pneumonia in pregnancy and may lead to severe adverse maternal and fetal outcomes. Severe CAP (SCAP) is defined as the need for invasive mechanical ventilation and with septic shock with the need for vasopressors. This study aimed to analyze the clinical characteristics and factors associated with SCAP in pregnancy. The present study was a case-control study of pregnant women hospitalized between September 2012 and September 2017 at nine tertiary hospitals in China. Among 358,424 pregnant women, we found 35 SCAP cases and 393 common CAP cases. The 35 SCAP cases were matched 1:4 with common CAP cases (n = 140), based on patient age and gestational weeks. Infection indicators, hemoglobin, platelets, coagulation function, liver, and kidney function markers, myocardial enzyme, arterial oxygen pressure/fraction inspired oxygen (PO2/FiO2), and partial echocardiographic results were different between the two groups at admission (all P < 0.05). The univariable analyses indicated significant differences for hemoglobin, BMI, irregular obstetric examination, albumin, and white blood cells (all P < 0.05) between the common CAP and SCAP groups. The multivariable logistic regression analysis showed that hemoglobin (OR = 0.87, 95% CI: 0.77-0.97, P = 0.01), BMI (OR = 0.42, 95% CI: 0.22-0.81, P = 0.01), and serum albumin (OR = 0.37, 95% CI: 0.19-0.69, P = 0.002) were independently associated with SCAP. Anemia and low serum albumin are possibly associated with SCAP in pregnancy. The results indicate that anemia and albumin levels should be examined and properly treated in pregnant women with CAP.