Abnormalities of the Third and Fourth Stages of Labour

Retained placenta

Acute inversion of the uterus

Repair of a third degree tear

RETAINED PLACENTA

The placenta is retained when it is not delivered from the uterus within 30 minutes of delivery of the baby. At times, the placenta is not truly retained, & it may be removed by simply lifting it out of the vagina, or manually helping it out of the cervix.

Management of retained placenta

1. Ensure that the bladder is empty by passing a urinary catheter
2. Start an infusion with oxytocin 20 units in 1L Ringer-Lactate at 250 mL/hour
3. Observe the woman constantly for vaginal bleeding or placental delivery
4. If there is excessive vaginal bleeding, or if the placenta has not been delivered after one hour of oxytocin infusion, arrange for manual removal in theatre under general anaesthesia
5. Take blood for Hb & crossmatch, & order 2 units of packed cells on standby
6. Just before anaesthesia is given, check if the placenta has passed into the cervical canal or vagina
7. For manual removal, try to remove the whole placenta with the hands. Use the ulnar surface of the palm to create a cleavage plane. If instruments are required, use the largest available forceps & curettes, to prevent uterine perforation
8. Call for senior help if bleeding persists or if placenta accreta is suspected
9. Give ampicillin 1 g IV followed by amoxycillin 500 mg 3 times daily orally & metronidazole 400 mg 3 times daily orally for 5 days

ACUTE INVERSION OF THE UTERUS

This emergency requires immediate action to prevent haemorrhage, shock & maternal death. Acute uterine inversion may be caused by inappropriate cord traction on a fundal placenta in a flaccid uterus, without providing the necessary upward counter-pressure on the uterus. At times it occurs spontaneously. Often, clinical shock is greater than expected for the amount of blood loss.

1. Immediately treat shock with Ringer-Lactate given through 1 or 2 lines using large bore (16G) IV cannulas
2. Explain the problem to the woman
3. Order blood for transfusion if there is haemorrhage
4. Give pethidine 50-100 mg IV if systolic BP ≥90 mmHg
5. Do not remove the placenta if it is still attached to the uterus
6. Give salbutamol 250 mcg IV to relax the uterus
7. Place the flat hand against the inverted surface of the uterus and push the uterus (with placenta if attached) as high up into the vagina as possible and hold that position for several minutes. Reduction should occur with sustained upward pressure (Johnson method)
8. If reduction is not achieved, fill the vagina with 500-1000 mL of saline, using a vacuum cup or other device to provide an external seal (O’Sullivan method)
9. Once reduction has been achieved, give syntometrine 1 amp IM & oxytocin 20 units in 1 L Ringer-Lactate. Do not remove the hand from the uterine cavity until a firm uterine contraction is felt
10. Carefully deliver the placenta when signs of separation are observed
11. If the placenta is not expelled spontaneously from the uterus, manual removal  needs to be done in theatre 
12. Observe the woman closely for haemorrhage or re-inversion
13. Failed reduction requires laparotomy. Using Allis clamps, pull on the round ligaments where they enter the uterine constriction ring , with an assistant pushing the inverted uterus up from below (Huntingdon method)
14. A tight constriction ring may prevent reduction. At laparotomy, the ring can be opened by a low vertical posterior incision in the uterus (Haultain method). Then proceed with the Huntingdon method

REPAIR OF A THIRD DEGREE TEAR

In a third degree tear, the anal sphincter is disrupted, & there may be injury to the rectal mucosa

1. Repair should be performed by a doctor in theatre, or in labour ward if an epidural anaesthetic is functional
2. Use polydioxanone & polyglycolic acid suture
3. Repair the rectal mucosa first with 3/0 suture, continuous or interrupted
4. Follow this by repairing the rectal muscularis layer with 3/0 suture, continuous or interrupted. Include the internal anal sphincter in this suture
5. Identify the disrupted ends of the external anal sphincter on each side just above the anal verge & extract and hold them with Allis clamps
6. Repair the external sphincter with 4 simple 2/0 sutures, either as an end-to-end or as an overlapping anastomosis
7. Complete the repair as for episiotomy
8. Give antibiotic prophylaxis – ampicillin 1 g IV 6 hourly for 24 hours followed by amoxycillin 500 mg orally 8 hourly, with metronidazole 400 mg 8 hourly, for a total of 5 days
9. Give oral analgesia, e.g. paracetamol 1 g orally 6 hourly or ibuprofen 400 mg  orally 8 hourly for 3-4 days
10. Prescribe stool softeners, e.g. ispaghula or bran, or lactulose 10 mL 12 hourly orally for 5 days. Advise on a high fibre diet
11. Advise on pelvic floor exercises & ask the woman to report any anal sphincter incontinence to her clinic or doctor