The red blood cell distribution width is a measure of the variation of red blood cell volume. Recently, elevated levels have been associated with several disease processes such as heart disease and septic shock outcomes. Some have attributed this increase in red blood cell distribution width as a result of occult inflammation. In normal pregnancies red blood cell distribution width increases during the last 4 weeks before delivery. We therefore hypothesized that as a result of inflammation, preterm patients would have higher red blood cell distribution width compared with term women in a control group.
MATERIAL AND METHODS:
In a retrospective case–control study, we compared 150 randomly selected patients who spontaneously delivered before 37 weeks of gestation with 150 patients who delivered at term during the last 10 years at our hospital. Red blood cell distribution width, hemoglobin, hematocrit, and white blood cell count were compared at the day of admission and day of delivery. We excluded individuals with known infection, inflammatory diseases, and hematologic disorders.
Ages were similar in each of the groups (preterm 25±4.9 years, term 26.1±6.1 years). The average gestational was 33.1±4.6 weeks in the preterm group and 39.1±1.9 weeks in term. Red blood cell distribution width did not differ between the groups (preterm 13.7±0.98, term 14.2±1.9). Subanalysis of preterm patients with premature preterm rupture of membranes (n=52) or gestational age less than 35 weeks (n=72) did not result in a significant difference when compared with women in a control group.
To our knowledge, this is the first study to look at red blood cell distribution width in preterm patients. Red blood cell distribution width does not appear to be a significant marker for preterm delivery at this time.