. >> reporter: as ultraconservative baptists, the bates are now the largest family in america.ied with the duggars, who also happen to be their good friends. the bates feel it's up to god to handle family planning. wife kelly gave birth to all 19 kids. ♪ as the world >> reporter: from 23-year-old zach to 6-month-old jeb. at 45 years old, kelly says she could easily have more. you now have 19. are there more kids down the pipe, so to speak? are we looking at more bates kids in the future? >> whatever the lord gives us, we'd be grateful. >> reporter: we've been following the bates for nearly two years, through courtships, two pregnancies and even one of several miscarriages. a few years ago, kelly began taking hormones to help make her pregnancies viable. if you don't feel right taking birth control to stop a pregnancy, why is it okay to take medicine to help a pregnancy? >> well, for us, that would be like -- that baby is already alive. it is a life. >> reporter: the only way gil and kelly bates can afford to raise so many kids is by pinching pennies. while gil runs a modest tre