The Midwich Cuckoos -- John Wyndham

What if the women of a sleepy English village all became simultaneously pregnant, and the children, once born, possessed supernatural—and possibly alien—powers? A mysterious silver object appears in quiet, picture-perfect Midwich. A day later, the object is gone—and all the women in the village, they will come to learn, are now pregnant. The resultant children of Midwich are shockingly, frighteningly other. Faced with these unfathomable and potentially unstoppable children, the question arises: What will humanity do when faced with the threat of the unknown?