The Best Dark Horror and Fantasy 2010, edited by Paula Guran.
The Eddington triplets were each born with an extra mouth on their foreheads; the better to sing His praises, Father Quine had said, smiling. Justice Peck arrived, took two deep breaths, and burst into silent blue flame. The great granddaughter of Old Khoas was born flower-faced and her every breath was a yellow cloud of pollen. Jirrup the Younger emerged limbless and scaled, and like the original beast his eyes were eyes of gold. The blind watchmaker’s daughter Undulia grew monstrously fat and fetid as she approached her blessed day. She spilled her blue-eyed daughter in a ruinous, thick tide. To the shock of all, this new born daughter, grunting and wailing, then gave birth to another smaller girl the size of a fist, swollen with child. This last tiny daughter, still nameless, still shivering with the chill outside the womb, stood shakily and birthed a finger-sized son whose wormy penis dragged on the floor.
Wow, beautifully written, horrifically disturbing. I would have to rank the Ick Factor at a high 7.