Five of the 13 regained continence before the second birth, but two became incontinent again as a result of a second vaginal delivery.

BBC: Post-birth incontinence 'tough to fix'

The couple had traveled to Atlanta because they had found there a doctor who was willing to perform a vaginal delivery even if the babies were in the breach position.

CNN: STORY HIGHLIGHTS

If you include vaginal deliveries, more than half of all pregnant women receive this type of medication to reduce pain during labor and delivery.

CNN: Can C-section anesthetic lead to low back pain?