The placenta is a vital organ that supplies blood and nutrition to the fetus. During the third stage of labor, the body pushes it out as its work is done. However, if it doesn’t come out easily, it results in the retained placenta. This can be a serious problem that could cause life-threatening, severe infections and blood loss without prompt medical care. Keep reading as we tell you more about the causes of retained placenta, its risks factors, diagnosis, treatment, and possible complications.
What Is Retained Placenta?
Labor usually proceeds in three stages –
- The first stage is when you experience the contractions which dilate your cervix to prepare for childbirth (cervical dilatation up to10cm)
- Second is when your baby delivers.
- Third is when you deliver placenta and membranes, and goes on for five to 15 minutes.
Retained placenta is a condition in which you fail to expel placenta and membranes within 30 minutes of the birth of your baby. This condition is also known as retained fetal membrane or retained cleansing.
As per the US National Institute for Health and Care Excellence (NICE), the third stage is considered retained or delayed if it takes more than 30 minutes with active management, or 60 minutes with maternal effort (1).
What Causes A Retained Placenta?
There are three main reasons for retained placenta:
- Uterine Atony: The most common type of retained placenta is where the uterus does not contract enough or stops contracting for the placenta to come out from the uterus (2).
- Trapped Placenta: It occurs when the placenta detaches from the uterus but gets trapped behind the closed cervix. It usually happens when the cervix begins to close before the placenta is completely removed (3). Hour-glass contracture of uterus.
- Placenta Adherens: When complete or a part of the placenta is firmly attached to the uterine wall, it is known as placental adherens. In rare cases, it happens when the part of the placenta is deeply embedded into the wall of the uterus, known as placenta accreta. It is more likely to occur when the placenta embeds itself in a previous C-section scar.
If the placenta is grown all over the wall of the uterus, it is known as placenta percreta.
Some other rare causes include:
- Succenturiate Lobe: Retained placenta can also develop when a small piece of placenta is connected to the main part by a blood vessel that is left behind in the uterus. This blood vessel is known as a succenturiate lobe (4).
Retained Placenta Risk Factors:
We cannot predict if any of the above cases could happen to a mother. However, certain factors increase the risk of the condition (5).
- Premature labor or giving birth before the 34th week of pregnancy.
- Induction or augmentation of labor.
- Lobulated placenta.
- Previous cases of retained placenta.
- Having more than five births previously.
- Conceiving after the age of 35.
- Giving birth to a stillborn baby.
- Prolonged first or second stage of labor.
- Previous uterine surgery.
Signs And Symptoms Of Retained Placenta:
When there is retained placenta in the body, you will experience symptoms a day after your delivery. They may include:
- Foul smelling discharge containing large tissue residue
- Persistent bleeding
- Severe cramps and contractions
- Delay in milk production
The International Board Certified Lactation Consultant (IBCLC) Renee Kam states that the placental expulsion is the signal for the breastmilk production. If placenta remains inside the uterus, this signal is interrupted, and therefore the milk supply alters.
Diagnosis Of Retained Placenta:
A careful examination by your midwife or the doctor can diagnose the retained placenta. She checks if the expelled placenta is still intact with the uterus after delivery. Even a small retained portion can be a cause of worry.
In a few cases, your doctor may not diagnose the missing part of the placenta. But, when you begin to experience the symptoms after delivery, it signals the retention.
Complications Of Retained Placenta:
In a standard delivery, the uterus contracts to hinder all the blood vessels inside it. But, if the placental tissue is left in the uterus, it cannot contract properly, and the blood vessels continue to bleed.
If it is a managed third stage, and placenta delivery takes more than 30 minutes after the baby is out, the risk of heavy bleeding increases significantly. Excessive blood loss during the first 24 hours after delivery is called Primary Postpartum Hemorrhage (PPH) (6).
If there are still small fragments left in the uterus, it can lead to heavy bleeding even after three to seven days of delivery and infections later though it occurs in just one percent of all the births (7). This condition is called Secondary Postpartum Hemorrhage.
How You Can Separate The Placenta:
If your third stage of labor is taking time, you should try to breastfeed your little one or rub your nipples so that oxytocin hormone releases. It causes contractions in the uterus and helps in birthing the placenta and membranes (8). You should also try to change your position by turning upright so that gravity helps in expelling the placenta.
In a physiological third stage of labor, if the placental delivery does not happen within an hour, go for managed third stage. Your doctor gives an oxytocin injection for your uterus to contract. Also, your doctor will assist in pulling out the placenta.
Retained Placenta Treatment:
If the above doesn’t work, you may go for further treatments.
- Manual removal of placenta: Your doctor performs this either in a delivery room or operation theater. She will insert a catheter to empty the bladder, and give you intravenous antibiotics to prevent any infection. You will also get a local anesthesia, either spinal or epidural. The practitioner will then place her hand inside the uterus to remove the placenta. You will require more intravenous drugs after the manual placental removal for the uterus to contract (9).
- Controlled cord traction: This is performed when the placenta is separated from the uterus, but is still not able to come out. In this case, your doctor will gently pull the umbilical cord to help rid the body of the placenta (10).
- Curettage: In the case of placenta accreta, manual removal is done partially, and curettage removes the rest. Under this method, a curette is used to remove the placental debris from the uterus through scrapping (11).
- Hysterectomy: In the case of placenta percreta, where the placenta is deeply grown into the uterus, hysterectomy helps. It is a surgical process of uterus removal. The drawback in this treatment is you cannot carry pregnancies in the future (12).
Can You Prevent Retained Placenta?
- You cannot do much to prevent retained placenta.
- If you have experienced a retained placenta in a previous delivery, there is a higher risk of another one. You should inform your doctor so that she would pay close attention during the third stage of labor. Skin to skin contact with the baby could lessen the risk.
- Avoid prolonged use of artificial oxytocin (syntocinon) inductions so as to reduce the risk of retained placenta, caesarean section, and uterine scar. Too much oxytocin will lead to uterine atony, which is again a leading cause for retained placenta.
Retained placenta can cause complications and hence needs to be treated immediately. Since the condition may not be preventable, it is advisable to discuss with your doctor any history of the retained placenta or any other risk factors beforehand to help with the prompt treatment. In case breastfeeding or skin-to-skin contact does not work, your doctor may proceed with other medical or surgical treatments that include removing the placenta manually, curettage or hysterectomy. Remember to stay calm amidst these and trust the process.
- Third stage of labour.
- Shimma S Rahman et al.; (2008); Post partum haemorrhage secondary to uterine atony complicated by platelet storage pool disease and partial placenta diffusa: a case report.
- Blake Conley Rodgers et al.; (2013); A novel treatment for management of a trapped placenta using intracervical nitroglycerin tablets.
- Shunji Suzuki and Miwa Igarashi; (2008); Clinical significance of pregnancies with succenturiate lobes of placenta.
- M H Soltan and T Khashoggi; (1997); Retained placenta and associated risk factors
- C A Klufio et al.; (1995); Primary postpartum haemorrhage: causes aetiological risk factors prevention and management.
- Pavol Zubor et al.; (2014); Recurrent secondary postpartum hemorrhages due to placental site vessel subinvolution and local uterine tissue coagulopathy.
- Elizabeth Abrams and Julienne Rutherford; (2011); Framing Postpartum Hemorrhage as a Consequence of Human Placental Biology: An Evolutionary and Comparative Perspective.
- Ezinne C. Chibueze et al.; (2015); Prophylactic antibiotics for manual removal of retained placenta during vaginal birth: a systematic review of observational studies and meta-analysis.
- G Justus Hofmeyr et al.; (2015); Controlled cord traction for the third stage of labour.
- Carlos F Grillo-Ardila et al.; (2014); Prostaglandins for management of retained placenta.
- Clara Bodelon et al.; (2009); Factors associated with peripartum hysterectomy.