Nitroblue tetrazolium reduction by leukocytes in the cervix of pregnant women.

We examined nitroblue tetrazolium reduction activity in leukocytes from cervical mucus as well as peripheral blood from pregnant and nonpregnant women by histochemical methods. More than 90% of the cells examined were polymorphonuclear cells. Nitroblue tetrazolium reduction in polymorphonuclear cells from peripheral venous blood was significantly enhanced in pregnant women compared with that in nonpregnant women. However, there was no difference in activity between pregnancy periods. On the other hand, nitroblue tetrazolium reduction in cervical polymorphonuclear cells excluding women with cervicitis was also greater in pregnant women than in nonpregnant women. Moreover, activity in cervical polymorphonuclear cells gradually increased as pregnancy progressed. This enhanced activity in polymorphonuclear cells may be involved not only in the defense mechanism but also in cervical ripening in pregnancy.