The effects of umblical cord clamping time on lymphocyte subgroups in term and late preterm infants

To evaluate the effect of umblical cord clamping time on lymphocyte subgroups in term and late preterm infants. Seventy-four infants between 34 and 41 weeks of gestation were included in the study. Of these, 37 were umbilical cord clamped immediately after birth and the remaining 37 were clamped after waiting one minute. Babies were divided into two groups as term and preterm. The prenatal, natal, postnatal characteristics of the infants were recorded. Hematologic and lymphocyte subgroups were investigated in cord blood and venous blood at day 7. Lymphocyte subgroups were evaluated using flow cytometry. With the delay of cord clamping, the leucocytes count and the percentage of CD3+T lymphocytes in cord blood of preterm infants decreased and this decrease continued at day 7. On the contrary, CD19+B lymphocyte levels in the cord blood of preterm infants increased, and this increase continued at day 7. Also, the percentage of CD4+T lymphocytes of preterm infants decreased with the delay of cord clamping at day 7. There was no difference between groups for the rate of sepsis development. With the delay of cord clamping, the leucocytes count, the percentage of CD3+T, and CD4+T lymphocytes decreased, and the percentage of CD19+B lymphocytes increased in preterm infants. The delay in cord clamping time in term and preterm infants seems to have no impact on the rate of sepsis development. Larger series of studies are needed to assess the effect of these findings on the development of infection in late preterm infants who have delayed cord clamping.