ABSTRACT
Forty pregnant female albino rats of the Rattus Rattus Norvigicus strain were utilized in this work. They were divided into 10 rats in the control group, which were injected intramuscularly with distilled water [2 ml / kg / day] from the 6[th] to the 15[th] day of gestation, and 30 rats in the experimental group which were injected intramuscularly with 10 mg phenobarbital / kg / day during the period of organogenesis from the 6[th] to the 15[th] day of gestation. On the 20[th] day of gestation, the pregnant rats were sacrificed and the uterus and ovaries were removed. Gross morphological examination of all fetuses was performed then the fetuses were examined by free hand-razor blade sectioning, staining the skeleton with alizarin red stain and histological examination of serial sections of the fetuses using hematoxylin and eosin stains. The present study showed that administration of phenobarbital resulted in decreased number of pregnant rats which continued their pregnancy while the mean number of resorptions and dead fetuses was increased when compared to the control group. The fetuses exposed to phenobarbital in-utero showed under development and several congenital anomalies. The highest incidence of anomalies was recorded in the central nervous system in the form of hydrocephalus. Skeletal anomalies were observed in the form of delayed, incomplete or absent ossification in the lumber, sacral and tail vertebrae as well as bones of the hands and feet. Craniofacial anomalies were seen in the form of enlargement of the head, macroglossia, cleft palate, nasal septal defect and protrusion of eyeballs. Generalized oedema, cardiomegaly, bilateral polycystic lungs and club foot were also found. In conclusion, this study has revealed that phenobarbital administration during the period of organogenesis is teratogenic in albino rats. The possible teratogenic effect of phenobarbital in human being needs further investigations. The pregnant females should be prohibited from using this drug during pregnancy