The article mentions the cervix dilating during labor--but sometimes that can go way wrong. My sister was diagnosed with an incompetent cervix when she was pregnant with my nephew--she was dilating still in her second trimester. The doctor did a cerclage (stitched the cervix closed) and put her on bed rest. She managed to carry to term, but it was touch and go. The whole thing was such an ordeal, she doesn't plan to have any more kids even though she always wanted two or three.