eng Science and Education Publishing American Journal of Biomedical Research 2328-3955 2017-03-30 5 1 14 16 10.12691/ajbr-5-1-3 AJBR2017513 article Salami S.A piety1424@yahoo.com 1 Department of Physiology, Lagos State University College of Medicine, Ikeja Objective: Haematological effect associated with Ricinus communis oil (RCO) ingestion at different gestation periods was investigated in wistar rats. Methods: 30 pregnant rats were randomly shared into 5 groups of six rats each. Group 1 (control) received distilled water while groups 2-5 received 950 mg/kg BW RCO orally between gestation days (GD) 1-7, 7-14, 14-21, and 1-21 respectively. Maternal haematological parameters were determined by conventional methods and data were analyzed using graph pad prism software. Statistical significance was taken at p<0.05. Results: There were significant increases in packed cell volume (PCV), haemoglobin concentration (Hb) and red blood cell count (RBC) in GD 14-21 treated rats as compared to control. However mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH) decreased significantly. GD 1-7 treated rats showed a reduction in PCVwhen compared to control. Percentage variations/changes in leucocyte cells values were all not statistically different from control values. Conclusion: Oral RCO exposure at different gestation periods has no significant effect on differential leucocytes cells count but appears to reduce and enhance erythropoiesis at early and late gestation period respectively. http://pubs.sciepub.com/ajbr/5/1/3/ajbr-5-1-3.pdf ricinus communis oil gestation days haematological parameters pregnant wistar rats