The reticulocyte count and its subfractions in smoking and non-smoking pregnant women.

UNLABELLED Our objective was to compare the reticulocyte count and its subfractions in smoking and non-smoking women at different stages of normal pregnancy. STUDY DESIGN In 247 non-smoking and 123 smoking healthy pregnant women the reticulocyte count and its subfractions were compared at four different stages of pregnancy: 0-10, 11-20, 21-30 and 31-40 weeks. Exclusion criteria were a diastolic blood pressure > or = 90 mmHg, an endocrine disease or a coagulation disorder. Women in the smokers group smoked more than 4 cigarettes a day. Non-smokers were defined as women reporting no smoking at all. Blood samples were run on the Sysmex R-3000 reticulocyte counter. RESULTS The absolute reticulocyte count was lower in the smoking group throughout pregnancy, but this was only significant in the last ten weeks of gestation (71.9 x 10(9)/l versus 78.8 x 10(9)/l). There was no difference between the low fluorescence, the medium fluorescence and the high fluorescence proportions in the non-smoking and the smoking group. Both groups behaved similarly during pregnancy; there was a decrease of mature reticulocytes and a significant increase of more immature reticulocytes. CONCLUSION These data show a moderate measurable effect of cigarette smoking on the reticulocyte count and the absence of an effect on the reticulocyte subsets.