Placenta Accreta Spectrum: a “dangerous gap” in maternity care in the UK
“…they had to get several members of staff who were on call because they weren’t prepared… If they had found the condition before, none of this may have happened.”
“I get panicky when I hear sirens. I can’t drive past the hospital without feeling like I’m about to have a panic attack.”
Hundreds of mothers are banding together to campaign to address “a dangerous gap in maternity care” relating to placenta accreta spectrum (“PAS”). This rare complication of pregnancy can be life-threatening for both mother and baby. Campaigners say that many cases are not diagnosed until birth. The reality is that if the diagnosis is made too late, medical staff are often underprepared to deal with the surgery adequately.
Action for Accreta, a campaign led by survivors of PAS, is calling for more recognition of PAS, and changes to medical guidelines in order to diagnose and treat patients with PAS more appropriately.
This blog looks at PAS and its complications, and how the complications can be exacerbated by the failure to diagnose PAS before birth. It also looks at what Action for Accreta is doing to help.
What is PAS?
PAS is a rare complication of pregnancy, in which the placenta is abnormally attached into the wall of the uterus.
In a pregnancy uncomplicated by PAS, the placenta attaches to the lining of the uterus, and provides the baby with oxygen and nutrients. After the baby’s birth, the placenta detaches and is expelled (often called the “afterbirth”). Commonly, the uterus then contracts to prevent the area from which the placenta has been detached from bleeding.
Where the placenta is attached in an abnormal way to the wall of the uterus, it can be difficult for it to be separated during birth.
The most frequent complication of PAS is heavy vaginal bleeding, which can lead to low blood pressure and fainting. In extreme cases, it can be life-threatening for the mother.
Most of the time, Caesarean hysterectomy is required: delivery is carried out by Caesarean section, and the uterus is removed with the placenta still attached. This leads to the mother being infertile for the remainder of her life.
PAS shows many of the same early warning signs as sepsis, which contributes to its frequent misdiagnosis.
Different levels of severity
As suggested by its name, PAS is a spectrum. The different conditions within the spectrum are “placenta accreta,” “placenta increta,” and “placenta percreta.” In order to understand the differences, it is important to know that behind the uterus lining is a muscle layer of the uterus, which is called the myometrium. The conditions are defined as follows:
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Placenta accreta
Placenta accreta reportedly accounts for 78% of cases of PAS. It happens when the placenta invades through the lining and attaches to the myometrium.
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Placenta increta
Placenta increta reportedly accounts for 17% of cases of PAS. It happens when the placenta is embedded more deeply into the myometrium.
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Placenta percreta
Placenta percreta reportedly accounts for 5% of cases of PAS. It happens when the placenta passes through the myometrium and attaches to the outer layer of the uterus, called the serosa. It can then affect or even attach itself to surrounding organs, such as the bladder.
Factors increasing risk of PAS
The risk of PAS is increased by the presence of a scar on the wall of the uterus, such as a Caesarean section scar. This is because the placenta can attach to the scar.
Other risk factors reportedly include advanced maternal age, a higher number of previous pregnancies, and smoking.
Complications
For mother
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Bleeding
As mentioned above, it is very common for women who have had PAS to experience heavy vaginal bleeding following birth. Most women who have had PAS require a blood transfusion as a result; and some require repeated surgery following the birth to treat the bleeding. The blood loss can lead to anemia.
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Placental retention
This is when the placenta does not detach following birth.
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Damaged organs
In cases of placenta percreta, local organs can be permanently damaged by the placenta, such as the bladder or the bowel. The damage may be caused by direct tissue invasion, and/or haemorrhage during attempts at surgical separation. Surgical interventions such as cystectomy (bladder removal) may be necessary.
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Infertility
Mothers become infertile following hysterectomy.
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Psychological damage (e.g., PTSD)
The process of childbirth in these cases is often very traumatic for the mother, as she must undergo major surgery (often unplanned as discussed below), which can include organ removals as mentioned above. There have been cases where the extreme blood loss has led to PTSD diagnoses.
For baby
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Prematurity
The risk of premature birth is increased by PAS. Premature babies face risks due to underdeveloped organs, including breathing difficulties, heart defects, and brain damage.
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Fetal hypoxia
This is a broad term for oxygen deprivation to part of the body. Hypoxic-ischaemic encephalopathy (HIE) can occur if the brain does not receive enough oxygen around the time of birth. HIE can cause permanent brain damage, often leading to developmental delay, epilepsy and cerebral palsy.
Further complications if undiagnosed until birth
If undiagnosed, there is a high risk of mothers bleeding to death due to the extreme blood loss.
Action for Accreta reports that around 50% of cases of PAS are undiagnosed until birth. These cases are often diagnosed only once the abdomen has been opened for a Caesarean section, often following previously unexplained heavy bleeding and a traumatic birth process.
The reality of this is that specialist surgeons required to deal with the necessary surgeries for PAS (such as Caesarean hysterectomies) are often not in the room at the time of birth; this can lead to delays, panic, and inadequate management of the emergency.
The chances of the above complications such as PTSD for the mother and brain damage for the baby are increased by these circumstances. Delays obtaining specialist staff could exacerbate the amount of blood lost by the mother; further increasing risk of the baby experiencing HIE. Unplanned emergency procedures like hysterectomies may need to occur without prior counselling or consent.
Action for Accreta
On 5 May 2026, 100 women shared their survival stories of PAS, to raise awareness of the condition and to highlight the dangers of late diagnosis. Their stories highlight systemic failures in diagnosing PAS, and treating it once diagnosed. 61 of the survivors were undiagnosed until birth. You can read their stories here.
Action for Accreta is calling for:
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Tracking
Better data tracking with regard to PAS (how many women experience it per year, how many are diagnosed prior to birth, which hospitals detect it well, etc).
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Training
Staff to be trained to identify the condition earlier; and staff to be trained to stabilise and treat at the birth.
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Trust
Maternity units to be prepared with adequate equipment and protocols to stabilise and escalate births complicated by PAS safely and efficiently.
You can read more about their campaign here.
Baroness Amos is currently conducting a thorough independent investigation into NHS maternity and neonatal services in England, and she is anticipated to release her final report in June 2026. Her previous interim report published in February 2026 in this investigation did not highlight the systemic failures in relation to the diagnosis of PAS.
Please see the February 2026 report here.
