In women, pregnancy often results in a mild increase in the white blood cell count due to the effects of the embryo, while during the onset of labor and during the puerperium, there is a significant increase in white blood cells. The increase in leukocytes is predominantly an increase in neutrophils, while the increase in lymphocytes is insignificant, while monocytes and eosinophils remain virtually unchanged. Therefore the high percentage of neutrophils in women after pregnancy is not determined by the sex of the fetus, but is the result of the pregnancy itself. It can be caused by either a boy or a girl, so it is not possible to say that a high neutrophil percentage means that the pregnancy is with a boy.