Quantitative aspects of red cell size variation during pregnancy.

Red cell volume distribution curves may be readily obtained using electronic cell counters, and the proportion of cells that deviate from the normal population may be determined. In this study, we report the results of red cell volume distribution analyses in pregnant and non-pregnant females. The relationship between red cell volume distribution and other red cell indices is also studied. Statistical analysis showed good correlation between various Channelyzer parameters and red cell indices including Hb, RCC, MCV, MCH, and MCHC. A significant proportion of pregnant patients showed abnormal red cell volume distribution curves particularly in the latter half of pregnancy. During the latter half of pregnancy there was an increased proportion of microcytic cells in 8% of patients and evidence for macrocytosis was found in 67% of patients. In general there was good correlation between stages of gestation and Channelyzer parameters associated with macrocytosis. It is suggested that analysis of red cell size, which may be simply performed with minimal quantities of blood and inconvenience using the Channelyzer, could give insight into those conditions associated with variation in red cell size including iron deficiency and folate deficiency in pregnancy and it is conceivable that repeated estimations of these parameters could obviate the need for blanket administration of haematinics to the pregnant patient.