[Quantitative study of nonsegmented and segmented neutrophilic granulocytes in newborn]

Serial white blood cell counts were studied in 20 healthy full-term babies and 252 newborn babies of different birthweights (61 of them without and 191 with perinatal risks). Nonsegmented (band form) and segmented neutrophils participate in roughly equal quantities in the physiological postnatal neutrophil reaction, which begins 1 hour after birth (8100/mm3 +/- 2600), reaches the peak after 9 hours (15 500/mm3 +/- 4000), and drops to the initial level within 42 hours. During the first 3 days the shift to the left with the relative and absolute increase of the band forms is more significant for a perinatal infection than the rise of total neutrophil count, which can remain within the normal range. However, these changes are not specific for infectious diseases. In the period the white blood count has only a diagnostic value in relation with the age of the newborn in hours and with short term follow-ups. Newborns of low birth weight (under 2500 g) show lower absolute counts and less significant changes than newborns of normal birth weight.