Shelby Martin still can't believe she gave birth to a nearly 13-pound baby. This past summer, the Tennessee-based mom had the "perfect birth plan" in place before her fourth baby came into the world. Everything changed, however, when she and her partner, Joshua Thomas, found out their baby was measuring big. "There was a real risk he could get stuck during delivery," Martin, 30, shared with People in an interview published Tuesday, October 21. "That changed everything.