Haematological changes during normal pregnancy in New Zealand white rabbits: A longitudinal study

The present study was undertaken to investigate changes in haematology parameters over the course of normal pregnancy in New Zealand White rabbits. Blood samples were collected on gestational days (GD) 0, 4, 8, 12, 16, 20, 24, and 28. Red blood cell counts and haemoglobin concentrations on GD 20-28 were lower than those of normal non-pregnant rabbits. These values fluctuated slightly between GD 0 and 12 and subsequently decreased to reach a nadir on either GD 24 or 28. Haematocrit value in pregnant rabbits also decreased slightly in the third trimester, but the difference was not statistically noticeable. Mean corpuscular volume in pregnant rabbits increased gradually during the course of gestation and was larger on GD 24 than that in non-pregnant rabbits. There were no differences in mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration between pregnant and non-pregnant rabbits. Platelet counts on GD 24-28 were lower than that of normal non-pregnant rabbits. These values increased slightly in the first half of gestation and then decreased to reach a nadir on GD 28. Total white blood cell and lymphocyte counts on GD 24 were lower than those of normal non-pregnant rabbits. These values increased maximally by GD 4 and then decreased progressively to a minimum level on GD 24. No significant differences were observed in the numbers of neutrophils, eosinophils, basophils, and monocytes between pregnant and non-pregnant rabbits. Neutrophil counts of pregnant rabbits fluctuated minimally between GD 0 and 12 and then decreased to reach a lowest level on GD 24. Eosinophil counts increased to a maximum value on GD 4 and subsequently decreased to reach a nadir on GD 24. Basophil and monocyte counts were not different throughout the course of pregnancy. These data can be used not only as a historical database for the effective evaluation of data from reproductive toxicology studies, but also as a contribution to biological characterization of New Zealand White rabbits.