There is ABSOLUTELY no way an x-ray or ultrasound of your pelvis has ANY bearing on your birthing potential. Pelvises are not fixed like fences, they swing like gates and babies mold. Even breech babies bums mold perfectly and so do their heads, they just do it in reverse. How your pelvis looks when you're lying down has nothing whatsoever to do with how it performs when you're brimful of relaxin and progesterone and in an upright open position with a baby being pressed down by a powerful uterus. Obviously breech babies can be born or we wouldn't keep producing them.