Obesity in pregnancy alters maternal immune function

Objective Obesity in pregnancy is associated with an increase in infectious morbidity such as endometritis, intra- amniotic infection, and wound infections which could result from impaired immune function. The objective of this study was to determine whether obesity in pregnancy alters T lymphocyte sub-populations or function. Methods Women were recruited for the study between 24 and 28 weeks of pregnancy in two groups based on pre-pregnancy BMI; obese (OB) had BMI > 30 (N=12) and lean controls (C) had a BMI 20–25 (N=10). Flow cytometry was used to measure cell populations and intracellular cytokine expression. In addition lymphoproliferation was assessed with 3H-thymidine incorporation. Conclusion Obese women had fewer CD8+ cells (OB 15.1+6% vs. C 25.9¬+8.2%) and RA+ (OB 53.5+10.4% vs. C 66.8+17.2%) cells compared to lean controls (p<0.05). In addition, obese pregnant women had significantly impaired cell proliferation in response to PHA 5ug/ml and anti CD3 1ug/ml, 5ug/ml and 10ug/ml compared to the lean pregnant women (p<0.05). These marked differences in the immune response of obese and lean pregnant women may explain the increase in infectious morbidity in obese pregnancy and have implications for fetal health and diseases in later life. Grant Funding Source: Tufts Medical Center research grant and USDA grant #58-1950-7-707