Objective: To evaluate lymphocyte subpopulations in pregnant women with intrauterine growth retardation (IUGR).
Study design: Forty-two normotensive and healthy women with singleton pregnancies and intrauterine growth retardation were studied in the third trimester of pregnancy and compared with 42 normal pregnant women. Peripheral blood lymphocytes were studied using murine monoclonal antibodies and flow cytometry.
Results: B-lymphocytes in both total number (312.54 vs. 163.19 cells/mm3; P = 0.000003) and percentage (11.04% vs. 7.07%; P = 0.000002) were significantly increased in patients with IUGR in comparison to normal pregnant women. Significant correlations were found between birthweight and both total number and percentage of lymphocytes B. In primigravid women, we found that women with IUGR had a higher total lymphocyte count (2749.09 vs. 2130 cells/mm3; P = 0.006), higher T-lymphocyte count (2053.77 vs. 1676.40 cells/mm3; P = 0.02), higher B-lymphocyte count and percentage (309.13 vs. 145.36 cells/mm3; P = 0.000001) (11.45 vs. 6.81%); P = 0.00001), higher CD4 lymphocyte count and percentage (1342.68 vs. 972.22 cells/mm3, P = 0.001) (49.18 vs. 44.04%; P = 0.04), lower CD8-lymphocytes percentage (28.27 vs. 32.9%; P = 0.04), and higher CD4/CD ratio (1.83 vs. 1.46; P = 0.02) than the normal control group.
Conclusions: B-lymphocytes are increased in women with IUGR in comparison to women with normal pregnancies and there was a significant negative correlation between maternal B-lymphocytes and birthweight. With respect to T-lymphocytes, the immunological profile is different according to the presence or absence of a previous pregnancy. Fetal immunological rejection could be involved in the pathogenesis of IUGR in primigravid women, but in multigravid women there were no differences between women with IUGR and those with normal fetal growth.