Variations in Leucocyte Count During Menstrual Cycle

Abstract

The neutrophil counts of seven women, three taking oral contraceptives and four not taking them, showed cyclical variations during the menstrual cycle, most consistently a fall in the neutrophil count at menstruation. The neutrophil count in women not taking oral contraceptives rose to a peak twice during each cycle. One woman not taking oral contraceptives was studied in detail over eight consecutive menstrual cycles. She showed two neutrophil peaks per cycle and a similar variation in the monocyte count. The eosinophil count showed a reciprocal relation with the neutrophil count and the basophil count fell in mid-cycle. The changes in her neutrophil count seemed to follow changes in oestrogen level with a delay of one to two days. Oestrogen probably promotes release of neutrophils from the bone marrow rather than from the marginated pool. © 1975, British Medical Journal Publishing Group. All rights reserved.