Longitudinal study of CD4⁺cell counts in HIV-negative pregnant patients

OBJECTIVE: To evaluate the absolute CD4+, CD8+, and lymphocyte cell counts and percentages from the first trimester through 6-12 weeks post-delivery in normal human immunodeficiency virus (HIV)-negative pregnant patients. METHODS: A longitudinal laboratory analysis was performed during pregnancy that involved 51 HIV-negative subjects with blood analysis obtained in all trimesters, at delivery, and 6-12 weeks post-delivery. Twenty-five HIV-negative non-pregnant controls were also evaluated. Blood was analysed for absolute CD4+, CD8+, and lymphocyte cell counts and percentages. Means, standard deviations, trends, and differences were examined. RESULTS: The mean white blood cell (WBC) count is elevated above the non-pregnant state and this parameter increases through the pregnancy up to and including parturition. The mean absolute lymphocyte cell count, lymphocyte percentage, and absolute CD4+ cell count are significantly lower during pregnancy and the progression through pregnancy appears U-shaped. The mean absolute CD8+ cell count is not significantly different. The CD4+ and CD8+ percentages are higher during pregnancy and this elevation persists into the 6-12 week post-delivery time period. A 3-digit drop in CD4+ percentage is common during pregnancy between blood draws; whereas, a 30% decrease or more in absolute CD4+ cell count is rare. CONCLUSIONS: By longitudinal analysis, pregnancy appears to significantly elevate the mean values of the WBC count, CD4+ percentage, and CD8+ percentage, but significantly decreases the absolute lymphocyte count, lymphocyte percentage, and absolute CD4+ cell count when compared to non-pregnant controls. The mean absolute CD8+ cell count appears to be unaffected.