incompetent cervix

• an internal os >1.0 cm (by US) is considered dilated
• normal cervical length is >3.0 cm

• tx: circlage
  • contraindicated if fetal parts or cord are seen in the cervical canal

• hourglass deformity:
  • seen when the cervix is open to the external os
  • amniotic membranes herniate through to the vagina

© 2002, C.E. Kahn, Jr.
2002-04-18