- What is Placenta Accreta Spectrum?
What is placenta accreta spectrum?
“Placenta accreta spectrum” covers a range of clinical conditions where the placenta is imbedded too deeply into the lining of the womb. The placenta is a temporary organ that connects the unborn baby to the wall of the womb via the umbilical cord. It provides oxygen and nutrients to the baby and removes waste products. In a normal pregnancy, the placenta will separate from the lining of the womb after the baby has been delivered. In cases of placenta accreta spectrum, the placenta is strongly attached to the lining of the womb and does not separate after the baby is born. The condition is rare, however due to various factors such as an increasing caesarean section rate and fertility treatments, placenta accreta is becoming more common. At the National Maternity hospital, between 5 and 10 patients are diagnosed with placenta accreta spectrum every year currently.
What is the difference between placenta accreta, increta and percreta?
Placenta accreta spectrum consists of three conditions; placenta accreta, placenta increta and placenta percreta, depending on how deeply the placenta is attached to the lining of the womb. Normally, the placenta attaches to the endometrium, the innermost lining of the womb However, in placenta accreta spectrum the placenta has grown beyond the endometrium .
Placenta accreta - the placenta has grown beyond the endometrium and has attached strongly to the myometrium, the muscular layer of the womb.
Placenta increta, the placenta has grown beyond the endometrium and has grown into and deeply invaded the myometrium.
Placenta percreta -, the placenta can attach and grow so deeply into the lining of the womb that it grows right through the outermost layer of the womb, the uterine serosa and often impacts other organs, such as the bladder.
- What causes placenta accreta spectrum to develop?
What causes placenta accreta spectrum to develop?
Placenta accreta spectrum usually affects patients with one or more known risk factors.
The most common risk factors are:
- Having had a previous caesarean section. Placenta accreta spectrum can develop even after only one caesarean section. The higher the number of previous caesarean sections, the greater the risk.
- Having a low-lying placenta, a condition known as placenta previa. However, most women who have placenta previa do not have placenta accreta.
- Having had previous removal of a fibroid, a surgical procedure known as a myomectomy.
- Previous surgery for a miscarriage such as a “D&C”, Dilation and curettage
- Previous “stuck placenta” in a prior pregnancy requiring removal in an operating theatre, referred to as “Manual Removal of Placenta”
- Infertility treatments such as in-vitro fertilization
- Patients who have a combination of previous caesarean section and have a low-lying placenta (placenta previa) are at greatest risk of developing placenta accreta spectrum
- Some patients may have no know risk factors, however this is very rare
- How is placenta accreta spectrum diagnosed?
How is placenta accreta spectrum diagnosed?
Usually there may be no signs or symptoms of placenta accreta. Some women may present with bleeding.
Placenta accreta spectrum is diagnosed on ultrasound. Diagnosis during pregnancy is important as it this allows the appropriate management and treatment plan to be put in place. Usually a number of ultrasounds are performed throughout the pregnancy to look closely at the placenta as the pregnancy progresses. While it is possible to diagnose the condition at any stage during pregnancy, usually the first signs are not seen until the 20 – 22 week anatomy ultrasound.
Sometimes an MRI is arranged. MRI uses a strong magnetic field and radio waves to create detailed images of the organs and tissues within the body. While ultrasound is the best test to look at the placenta itself, an MRI allows the team of doctors to get more detailed images of how attached the placenta appears in relation to other organs surrounding the womb, such as the bladder. An MRI is also helpful where the diagnosis is not clear from the ultrasound images. Your team of doctors will use both the ultrasound and MRI images together to determine how deeply the placenta is attached to the lining of the womb. Both ultrasound and MRI are safe during pregnancy and do not harm your baby.
- How is placenta Accreta Managed?
How is placenta Accreta Managed?
Following a diagnosis of placenta accreta a number of specialists become involved in your pregnancy care . These include
- consultant obstetrician ,
- anaesthetist ,
- a specialist in gynaecology surgery (usually a gynaecology oncologist ) ,
- Radiologists ( xray doctors )
- ultrasonographers ,
- midwifery input.
- urologists( surgeons which look after your bladder your kidneys )
A patient support group is also available and they may contact you.
Each month at a multidisciplinary meeting members of the team meet to discuss your care and put in place a plan for the delivery of your baby .
You will meet a number of these specialties during your care .
You may need to be monitored as an inpatient in hospital . This may happen if you have had any bleeding or pain during your pregnancy or if you live a long way from the hospital. Some patients may be suitable for outpatient management.
An elective caesarean section is usually performed to deliver the baby . In the majority of cases a hysterectomy is also performed. This generally occurs between 34-36 weeks gestation . As the baby is delivered early you will need to receive 2 doses of antenatal steroids for your baby prior to your caesarean section . These help aid the babies lung development. Your baby may need to spend some time in the neonatal unit following delivery. A paediatric team are present at the delivery.
2 types of anaesthesia are used to perform the surgery
Spinal anaesthetic . A needle is inserted into the back and the medication given makes you numb from the breasts to the tips of your toes . You do not feel any pain but you will still have sensation to touch . This allows you to be awake for the delivery of your baby .
General anaesthetic . This is where mediation is given via a drip and face mask to make you go sleep . This can be given following the delivery of the baby to proceed with the hysterectomy or it may be given at the start of the procedure.
A large incision is usually made on your abdomen usually from your pubic bone to above the belly button . In a selected number of cases an incision across your can abdomen can be performed. This incision is usually closed with surgical staples and a special dressing known as a pico dressing is applied .
Following the delivery of the baby , the placenta remains inside the womb. A hysterectomy ( removal of your womb and fallopian tubes) is performed. The reason for this is to prevent heavy bleeding from the placenta as it is unable to detach from the lining of the womb. The ovaries are left behind so you do not go into menopause.
You may require a blood transfusion during or post surgery . A special machine called a cell salvage is used to collect your own blood during the surgery . This is then given back to you following the procedure . You may also require blood from the laboratory .
Some mothers may need to have the surgery performed at either St Vincents University Hospital or the Mater Misericordiae hospital . Following surgery at these hospitals you may be transferred back to the National Maternity Hospital after a few hours .Some mothers may need to stay overnight for observation. This is usually in a high dependency ward .
In selected cases a specialist X-ray doctor may insert balloons Into the blood vessels that supply the womb during the surgery . This helps to reduce the blood loss.
A planned delivery is the safest method for mother and baby . If there is any severe bleeding or imminent concerns about the health of the mother or baby an emergency delivery may need to be performed .
- What are the risks associated with placenta accreta?
What are the risks associated with placenta accreta?
- Heavy bleeding
- As the risk of bleeding is high during a hysterectomy, it may be necessary to place “balloons” in the blood vessels which bring blood to the womb to reduce the risk of bleeding heavily
- The balloons are usually inserted through a blood vessel in the groin
- The balloons are inflated during the surgery and help to reduce the amount of blood lost during surgery
- This is only performed in select cases
- The need for a blood transfusion – 3 in 10 patients require a blood transfusion
- Hysterectomy and loss of fertility
- Damage to the organs close to the womb – most commonly the bladder
- In some cases, where the placenta is invaded very deeply into the womb, the ureters (tubes which carry urine from the kidney to the bladder) are at risk of being injured. This is because the ureters lie very close the womb. To reduce the risk of injury, a small stent may be placed in the ureter to protect the ureters during the surgery.
- Developing a blood clot in the leg or the lung
- Infection of the wound following surgery
- Most commonly associated with heavy bleeding
- Higher risk if placenta accreta spectrum is not diagnosed during the pregnancy
- For baby – early delivery requiring admission to the special care unit
- Approximately 1 in 10 patients will have a severe complication
- Postnatal Period
After surgery you will be monitored closely in a high dependancy ward. In most cases this is only for one night. Following this you are transferred back to post natal ward.
A urinary catheter is inserted during your surgery. This stays in place until you are able to walk safely to the bathroom. Usually the next day.
A number of drips and monitors may be still attached following your surgery. Once again these are all usually removed the next day.
Blood test are usually taken to check your iron levels and the function of your kidneys.
To prevent blood clots forming ( a risk factor following surgery ) you are required to wear stockings for the duration of your stay in hospital. A small blood thinning injection is also given every day. Some mothers may require this medication at home for a few weeks following delivery. We encourage you to mobilise as soon as it safe to do so. A member of the physiotherapy team will help and guide you on how to do this safely.
You will be given pain relief medication to help ease any post operative pain. This can be in the form a tablets or a drip.
Most women are allowed to eat and drink soon after surgery.
You will normally be in hospital for approximately 4-5 days. If there are any concerns or complications you may need to stay for an extra period of time.
- What happens to my baby?
What happens to my baby?
Following the delivery of your baby he or she will need to be admitted to the neonatal unit. This is usually because we are delivering the baby earlier than expected. They may need help to fed, breathe and to regulate their temperature. Once mobilising you can visit your baby in the unit.
If you have your surgery in either St Vincents Hospital or the Mater Misericordiae Hospital, a team of Paediatric doctors and neonatal nurses will be present for the delivery of your baby. This is known as the neonatal transport team. Following delivery they will accompany your baby back to the neonatal unit.
How long your baby stays in the baby unit usually depends on how early they are born.
Your baby may need to stay in the hospital after you are discharged.
- What do I need to know about going home?
What do I need to know about going home?
On average it takes up to 6 weeks to recover from surgery. For some women this may be longer.
You may be discharged home before your baby can be discharged from the neonatal unit.
It is important to have someone at home with you.
On discharge from hospital you will be given a prescription for pain relief and any other medication that you may require such as the blood thinning injections, antibiotics or iron supplementation.
It is important to take these medications as directed.
It is important to eat and drink as normal.
The physiotherapists may give you exercises to perform at home . Avoid heavy lifting and strenuous exercise for the 1st 6 weeks.
You are advised not to drive. The can be for up to 6 weeks post surgery. You will need to check with your insurance company.
The public health nurse will visit with you post surgery. You may also be asked to attend you gp to have your staples removed. This usually 7-10 days post surgery.
A 6 week follow up appointment will be given to you.
If you have any concerns or are feeling unwell post surgery it is important to contact the hospital. You may be asked present to your GP or to the emergency department.
Some women may experience mental health changes following the birth of your baby.
These can include:
Baby blues - common , normal usually day 3-5 after the delivery of your baby.
Post natal depression 10-15% of women within the first year of giving birth.
Post traumatic stress disorder - a disorder which may present with intrusive and persistant re-experiences of traumatic events.
Support services are available trough the hospital via the perinatal mental health health department. You can also access help via your GP.
- Patient Stories
Is placenta previa part of placenta accreta spectrum?
No, placenta previa is not part of placenta accreta spectrum. In placenta previa, the placenta is low lying and covering the cervix. The placenta is normally attached to the lining of the womb and will separate naturally following delivery of the baby. The term “previa” refers only to the location of the placenta inside the womb and there is no invasion of the placenta into the womb.
Are all cases diagnosed during the pregnancy?
In the National Maternity Hospital, 92% of cases are diagnosed during the pregnancy. Approximately 1 in 10 patients will not be diagnosed during pregnancy and the diagnosis is only made either at the time of caesarean section or following a vaginal delivery, where the placenta does not separate from the lining of the womb.
What happens after a diagnosis of placenta accreta?
Where a diagnosis of placenta accreta spectrum has been made, delivery of the baby will be by caesarean section.
In most cases, the baby will be delivered a number of weeks before the due date. Usually the delivery is planned for between 34-36 weeks. In some cases, where a diagnosis of placenta accreta spectrum is made very early in the pregnancy, delivery before 30 weeks may be necessary. Approximately 80% of patients will have an elective delivery if a pre-term delivery is planned. In some circumstances, an emergency delivery is necessary. This occurs in approximately 20% of patients. The most common reason for an emergency delivery is if you start bleeding or going into labour before your scheduled delivery date.
A planned delivery is safer for mother and baby as it minimizes the risk of bleeding and needing an emergency caesarean section.
Hospital admission may be necessary for close observation and monitoring in some cases, especially in cases where there has been bleeding in the pregnancy.
Is bed rest required once a diagnosis of placenta accreta spectrum has been made?
There is currently no evidence to support that bed rest is necessary. Any limitation to normal activities will be discussed on an individual case basis with the team providing care. Sexual intercourse can cause bleeding from the placenta and is not recommended once a diagnosis of placenta accreta spectrum has been made.
During the caesarean section what type of anesthetic is given?
The options for pain relief include either a spinal anaesthetic or a full anaesthetic.
Spinal: an injection is given into the lower back and the patient is numb from the waist down. This means the patient is awake for the delivery of the baby.
General anaesthetic: during a full anaesthetic the patient is fully asleep for the delivery of the baby. In cases where the patient remains awake for the delivery of the baby, they will routinely be then given a full anaesthetic and put to sleep after the baby has been delivered and while the hysterectomy is completed.
Many patients prefer to go asleep at the beginning of the surgery. This may be necessary in some cases to provide adequate pain relief or where heavy bleeding occurs.
What else is involved in preparation for surgery?
Arterial line: before the surgery is started, an arterial line will be placed in the patient’s wrist, as well as a number of other drips in the arm.
Central line: A central line is a long, thin, flexible tube placed in the neck through which medicines, fluids, or blood products can be given as well as blood tests taken. A central line may stay in for number of days, if required, and avoids the need to repeatedly use new needles to give medication and take blood tests.
Urinary Catheter: A tube will be placed in the bladder before surgery is started. This usually stays in until the patient is able to walk comfortably, however where a balder injury has occurred the catheter may need to stay for a number of days.
Why is removal of the womb necessary in placenta accreta spectrum?
In placenta accreta spectrum, once the baby has been delivered, the placenta stays firmly attached to the womb and there is a high risk of bleeding if attempts are made to remove the placenta.
Therefore, often the safest option is to remove the womb (hysterectomy) with the placenta to minimise the risk of blood loss.
Approximately 80% of patients will require a hysterectomy
- At the time of delivery of the baby, the womb is removed in the same surgery
- This may require a large incision on the skin from above the belly button to just above the pubic bone
- The baby will be delivered through an incision away from the placenta and the placenta is left undisturbed. This minimizes the risk of bleeding
- The womb is removed along with the fallopian tubes and the ovaries are left inside
Are there any alternative treatment options to hysterectomy?
While most patients with a diagnosis of placenta accreta spectrum will require removal of the womb, in some select cases other treatment options are available
- 1) The placenta may have grown deeply into the lining of womb only in one small area. The rest of the placenta may not be stuck and is attached normally to the rest of the womb. In these cases, this small area of the womb can be removed along with the placenta and the womb left inside. This is only suitable in a small number of cases. In cases where this approach has been planned during the pregnancy, sometimes during surgery it does become necessary to remove the womb. This may be because the placenta is grown more deeply into the womb than expected from ultrasound or due to heavy bleeding.
- 2) If the placenta starts to separate by itself, a gentle attempt to remove the placenta can be made. However, this is often associated with heavy bleeding and will only be attempted if the placenta starts to separate naturally.
- 3) In a few cases, there may be very little blood loss and the placenta can be left inside the womb, where it may absorb over a few months. However, this is not always successful, and 6 in 10 patients will need a hysterectomy at a later date. There is also a risk of heavy bleeding or developing an infection.
Will the ovaries be removed at the time of surgery?
No, your ovaries will not be removed. If you require a hysterectomy, your fallopian tubes will be removed and your ovaries left inside
What happens after the surgery?
- Most women will need to be admitted to the high-dependency unit for close monitoring and observation for at least 24 hours. During this time, the patient will have a catheter in the bladder and may have a number of drips in the arms and neck.
- Where the surgery has been uncomplicated and the blood loss minimal, the patient may only need to spend 3-4 nights in hospital after the delivery.
- However, if there was a complication or heavy bleeding, intensive care admission may be necessary for closer monitoring.
Will the baby need admission to the special care unit?
- The baby will usually need admission to the special care unit for support with breathing and feeding. This means that mother and baby will be separated following delivery.
- Steroids will be given to the mother which help to mature the baby’s lungs before delivery.
- How long the baby spends in the special care unit will depend on how early the baby is born.
Is it possible to breast feed after a hysterectomy?
Yes it is possible to breastfeed after a hysterectomy. Breastfeeding can be challenging with a premature baby after major surgery and lactation support is available if requested.
What recommendations are there for recovery from surgery?
- Iron supplementation if iron level was low on leaving the hospital
- To minimise the risk of a blood clot, wear compression stockings for 6 weeks and take blood thinning injections as prescribed, usually for 10 days
- The wound will take around 3-6 weeks to heal
- Regular pain relief is recommended after surgery in order to minimise break through pain
- Physiotherapy for pelvic floor function
How long will it take until normal activities can be resumed?
Recovery time is different for every person. It may take at least 6 weeks for the wound to heal and post-surgery pain to resolve. However, for some women this may take longer. During the first 6 weeks driving is not recommended.
- A postnatal review will be arranged in the hospital 6 weeks after surgery for a check up
- Patients may have spent a long time in the hospital before their surgery, and may go home before their baby has been discharged from the special care unit, so this can be a very challenging time for patients and their families
- Some women may suffer from depression, anxiety and post traumatic stress disorder
- Where a hysterectomy has been performed, it will not be possible to have further pregnancies and this can create additional anxiety around loss of fertility
- Follow up and support services are available in the hospital and through the patient support group to address any ongoing concerns.
- Additional Support