A longitudinal study of leucocyte blood counts and lymphocyte responses in pregnancy: a marked early increase of monocyte-lymphocyte ratio
Valdimarsson, H.; Mulholland, C.; Fridriksdottir, V.; Coleman, D.V.
Clinical and Experimental Immunology 53(2): 437-443
1983
ISSN/ISBN: 0009-9104 PMID: 6603933 Document Number: 213759
Pregnant women (77) were studied repeatedly from the 1st trimester until 4 wk after delivery. Neutrophil count was increased but constant in all stages of pregnancy. There was a marked increase in monocyte numbers in the 1st and early 2nd trimester, followed by a gradual decrease towards normal before term. A progressive decrease in total lymphocyte count was observed up to 25-28 wk, when it increased again, although not reaching the non-pregnant level before term. These fluctuations in monocyte and lymphocyte numbers have not been described before, could explain contradictory findings of previous studies, and may be important in relation to the mechanisms which prevent rejection of the fetal allograft. Absolute T cell counts were not significantly decreased, but a striking reduction was observed in B cell numbers in early pregnancy. Lymphocytes response to T cell mitogens was decreased throughout pregnancy. Immunological studies of pregnancy must take account of the dynamic nature of this condition.