Normally, placenta is usually expelled within 10 to 15 minutes of baby’s birth.
A retained placenta occurs when placenta fails to be delivered after 30minutes of the delivery of the baby. The failure of uterus to expel the placenta after this time can be attributed to:
What are causes of retained placenta?
- Mismanagement of third stage of labour: This includes fiddling with uterus, or overzealous massage of the uterus, and may cause an hour-glass constriction of the uterus.
- Hour- glass contraction: a contraction ring in the third stage caused by giving ergometrine and not expelling the placenta in time
- Faulty technique: This is where an inexperienced midwife tries to expel the placenta before it separated or is not quite competent with expulsion by fundal pressure.
- A full bladder: this may prevent adequate and effective uterine contraction and retraction and hence impedes placental expulsion.
- Retention of separated placenta: This is commonly caused by uterine atony and constriction ring.
- Poor and ineffective uterine contractions secondary to uterine inertia
- Morbid adherence of the placenta
What is morbid adherence of the placenta?
Retention of adherent placenta can occur either of the two ways:
- Ordinary adherence — its cause is not known but it tends to recur in the same patient. Where there is total adherence, there will no associated haemorrhage, where there is a partial separation, vaginal bleeding occurs. In each of these cases, manual removal of the placenta by a skillful birth attendant is recommended.
- Pathological adherence — this is a very rare condition. It occurs where there is no line of cleavage between the placenta and the uterine walls, usually because of the deficiency or absence of the deciduae. That’s, abnormal implantation of the placenta in the uterus results in this condition. Pathologic adherence of placenta occurs in three patterns:
Placenta accreta: This is when the chorionic villi invades up to the myometrium
Placenta increta: Here, the chorionic villi invade the myometrium.
Placenta percreta: The chorionic villi invade or penetrate the whole uterine wall to the serosal layer.
The exact causes of pathologic adherence of placenta are not properly understood but its risk factors are uterine scar, previous manual removal of the placenta and/or placenta praevia in the present pregnancy because of poor decidual reaction in the lower uterine segment.
What are dangers associated with retained placenta?
Retained placenta may cause atonic postpartum haemorrhage, particularly if it is partially separated. Its presence in the uterus inhibits adequate uterine contraction and retraction. The accompanying haemorrhage may result in shock.
Prolonged retention of the placenta can cause severe shock in the patient even in the absence of haemorrhage.
An attempt to do manual removal of the manual may expose the patients to complications such as rupture or inversion of the uterus and puerperal sepsis.
How to treat retained placenta
- Carefully monitor the patient’s pulse, blood pressure and vaginal bleeding
- Check and empty her bladder
- Rub up for contractions and deliver the placenta
- Gently try to deliver by controlled cord traction
- If the placenta does not leave the upper uterine segment after 30 minutes and there is no bleeding, suspect the retention of an adherent placenta and never attempt to separate the placenta. Partial separation would result in bleeding.
- Call in the doctor who will do manual removal of the placenta under general anaesthesia.
Manual Removal of Placenta
If the patient is bleeding is bleeding with the placenta in-utero, a dose of ergometrine (0.5mg) is administered intramuscularly or intravenously. Then manual removal of placenta is attempted.
What is manual removal of placenta?
This is procedure that where the midwife or obstetrician inserts his hand inside to remove retained placenta and membrane under aseptic technique so as to make the uterus to contract effectively and in turn prevents postpartum haemorrhage.
Manual removal of placenta is usually done by the obstetrician under general anaesthetic or using intravenous Pethidine (100mg) and chlorpromazine (Largactil, 50mg) or intravenous morphine (15mg), well mixed with 10ml of sterile water for injection and given very slowly.
If the retention is caused by constriction ring, which is usually diagnosed when an attempt is being made to remove the placenta manually, general anaesthesia can be given to relax the spasm. However, inhalation of one ampoule of amyl nitrite may also be helpful.
How to do manual removal of placenta
Method: Place one hand on the fundus to support the uterus, gently let the other hand follow the cord until it reaches the placenta, move hand up to the edge of placenta and find where it is partiality separated (remember, there won’t be bleeding if it is not separated) then move your hand up and down, until you have it completely separated then bring it out in your hand.
Do the following:
- Examine the removed placenta for its completeness.
- Properly empty the uterus of any blood clots and debris
- Rub uterus to contraction
- Encourage breastfeeding if the woman has not initiated because it helps in releasing more oxytocin.
- Administer uteronics(e.g. 10IU) intramuscularly to contract the uterus
- Give antibiotics such as Ampclox, or metronidazole to prevent infection
- Administer analgesia such as diclofenac or ibuprofen or injection to alleviate any pain.
- Thank the woman and make her comfortable.