The effect of prenatal administration of valproic acid on the survivability and day of hatching of chick embryo.

Objective: To assess the effects of prenatal administration of valproic acid on the survivability and day of hatching of chick embryo in comparison with age-matched controls. Methods: The experimental study was conducted at the Department of Anatomy, Regional Centre of College of Physicians and Surgeons Pakistan, Islamabad, from February 2010 to February 2011. Fertilised chicken eggs were divided into two groups, labelled as experimental group-A and control group-B. Group-A eggs were injected with valproic acid, incubated and hatched. Group-B eggs underwent sham treatment using normal saline. The fully hatched chicks were then evaluated for the day of hatching and survivability, on hatching or on day 22 of incubation whichever was earlier. Outcome was statistically compared with the controls using SPSS 10. Results: The two groups had 30 eggs each. In Group-A 23(76.66%) chicks hatched out, while there were 7(23.33%) dead chicks. In Group-B, 28(93.33%) chicks hatched out and 2(6.66%) were dead. Chicken embryos exposed to valproic acid in ovo showed increased mortality (p<0.001) and delayed hatching (p<0.001). Conclusion: Prenatal exposure of chick embryos to valproic acid decreased embryo survival and also delayed hatching compared to age-matched controls.