B- Bladder, V-Vagina, R-Rectum, C-Cervix
|B- Bladder, V-Fetal Head, C-Cervix|
c) Speculum or vaginal examination- cervical shortening (effacement) and dilatation of the internal os.
A patient who has had a previous second trimester loss or preterm delivery should be seen for pre-pregnancy counseling and assessment. A badly lacerated cervix can be repaired before the patient embarks on her pregnancy.
Early ultrasound scan is necessary for dating. Subsequent scans and vaginal examination will indicate the need for a cervical suture.
A Shirodkar suture using Merselene tape or a McDonald suture with #4 mersilk at the level of the internal os is the treatment available. This may be carried out under a spinal or a general anaesthetic.
|Incompetent Cervix with herniation of membranes||Shirodkar suture in place|
Prophylactic, Therapeutic and Rescue Sutures
Prophylactic suture may be placed when there is a clear history supported by pre-pregnancy hysterogram or Hegar dilator test. Success rate is very high in this group. However, some of the sutures may be unnecessary.
Therapeutic sutures are placed when there is clinical or ultrasound evidence of cervical incompetence in the index pregnancy. Success rate is high and all sutures are indicated.
Rescue sutures are those inserted as an emergency when the cervix is effaced and the internal os dilated, often with the membranes bulging into the vagina. (Hour glass appearance on sonogram). Success rate is low here with high complication rate (rupture of membrane, infection and bleeding)
Patients with cervical suture are monitored more closely with frequent assessment of cervical length by USS and/or pelvic examination. Cervical suture is usually removed at about 37 weeks of gestation and a vaginal delivery is expected. Occasionally, a cervical suture induces fibrosis and the cervix fails to dilate in labour requiring a C. Section for delivery.