Extract of Ocimum gratissimum (OG), also known as scent leaf, is popularly used to treat diabetes mellitus and its hypoglycaemic activity has been confirmed by in vivo studies. The aim was to investigate the effect of this extract on placenta development and birth outcome in diabetic pregnancy. Forty two pregnant rats weighing 150-200 g were used. They were divided into control and extract treated diabetic and non-diabetic groups with 6 rats in each subgroup. Extract treated groups were administered 200 and 400 mg/kg of ethanolic extract of OG orally after the induction of diabetes by administration of alloxan monohydrate after an overnight fast. Treatment commenced in the second trimester and lasted till end of pregnancy. On day 18 of pregnancy, 3 rats from each group were sacrificed and placentae harvested and weighed. On the day of delivery, birth weight and other parameters were recorded. Results show that OG administration caused a significant decrease in placental weights, birth weights, litter sizes and placental-birth weight ratio in both diabetic and non-diabetic pregnancy. In conclusion, the observed decrease in placenta-birth weight ratios may suggest a protective beneficial effect of this extract against macrosomia in diabetic pregnancies and increased risk of cardiovascular disease later in life.

Keywords: Ocimum gratissimum, gestational diabetes, placenta-birth weight ratio, pregnancy outcome, postnatal growth.