With the high incidence of pregnancy associated hypertension as well as its associated complications, there has been a need for the use of anti-hypertensive drugs, thus a careful study of current anti-hypertensive agents has become very imperative. The present work was aimed at investigating the effects of oral administration of nifedipine and labetalol on hypertensive pregnant rats. In this study twenty (20) pregnant female rats were randomly divided into four (4) groups of five (5) rats each and were treated as follows: Group 1: Normotensive pregnant control rats , Group 2: Hypertensive pregnant control rats, Group 3: Hypertensive pregnant rats + 51.1mg/kg b w of Nifedipine and Group 4: Hypertensive pregnant rats + 2.5 mg/kg b w of Labetalol. Hypertension was induced in rats by using 8% sodium chloride added to their regular feeds for a period of eight weeks. Subsequently, the elevated blood pressure was then confirmed with a tail cuff platysmograph. The female rats were mated with fertile male rats in a ratio of 2:1. The gestation day one was depicted as the day that copulation occurred as demonstrated by the presence of vaginal plugs; hence pregnancy and the male rats were then separated from the female rats and returned to respective cages. Treatment was given orally to animals once daily throughout gestation period in all groups till ten (10) days postpartum. The findings of our study showed that there was no significant change (p>0.05) on the maternal weight, gestational age, litter size, litter weight and crown rump of nifedipine and labetalol treated hypertensive pregnant rats in all groups when compared to control groups respectively. In conclusion, the present study have showed that oral administration of nifedipine and labetalol at doses of 51.1mg/kg b w and 2.5mg/kg b w produced no significant change on the maternal weight, gestational age, litter size, litter weight and crown rump length of litters of hypertensive pregnant rats.
