In the beginning of The World on Turtle's Back why did the husband become terrified?

In "The World on Turtle's Back," the husband becomes terrified when he discovers that his wife is pregnant with a child who possesses a unique nature. This fear arises from the belief that the child could be a powerful being, potentially embodying the duality of good and evil. The husband's anxiety is compounded by the supernatural elements surrounding the conception, leading him to worry about the implications of bringing such a child into the world.