Excessive weight gain during pregnancy has shown to increase blood volume, cardiac output and blood pressure during pregnancy and remains a global challenge even in the 21st century with attendant increase in mortality rate during child bearing. Hence, the quest for alternative management medication suffixed our investigation of the effect of allium sativium (garlic) on pregnancy, fetal weights and some hematological parameters. In this present study, 40 female wistar rats were divided into 4 groups of 10 rats each. Group A served as a normal control group and was fed with normal rats chow and clean drinking water ad libitium. Group B were induced with pregnancy and received 100mg/kg body weight of the allium sativium extract. Group C were also induced with pregnancy and received same dose of the extract as group B. Group D was non- pregnant group but received the same dose of the allium sativium extract as B and C respectively. Their body weights and hematological parameters ( RBC, WBC,PLATELETS, HB and PCV) were accessed prior to commencement of the experiment and on weekly basis for 28 days .ANOVA was used to analyze the data and probability level of P<0.05 considered significant. Result of the study shows there was a significant decrease in the body weights of the groups (D<b<a0.05) between groups B,C and D when compared with control group A. Groups A & D showed a significant increase in the packed cell volume (PCV) while B and C decreased significantly. The Platelet counts decreased significantly in all the groups compared to group A and there was no significant difference (P>0.05). The fetal weights, decreased in the groups that received the allium sativium extract than those that did not receive it, though there was no significant difference between them(P<0.05). Therefore, the result of this study suggests that the consumption of garlic during pregnancy has a beneficial effect in the reduction of both maternal and fetal body weights and could serve as useful agent in the maintenance of blood parameters including the fasting blood sugar level.