The Royal College of Obstetricians and Gynaecologists (RCOG) has published an updated Green Top Guideline on the diagnosis and management of Placenta Praevia and Placenta Accreta Spectrum. The updated guidance reflects considerable advances in clinical understanding since the last edition was published in 2018.
What has changed?
The guidance strengthens early risk detection and recognises that Placenta Accreta Spectrum is not exclusively linked to Placenta Praevia or a previous caesarean birth. It reflects current evidence linking Placenta Accreta Spectrum to other forms of uterine surgical trauma, including curettage, hysteroscopic surgery, endometrial ablation, uterine artery embolisation, and myomectomy.
The guideline also reflects the latest available evidence across several clinical areas, including:
- Caesarean scar ectopic pregnancy - a new guideline section reflecting this condition can be a precursor to both Placenta Praevia and PAS.
- Earlier identification of risk - strengthened guidance on the role of the first antenatal appointment and the 18–20 week anatomy scan in identifying women at high risk of Placenta Accreta Spectrum
- Specialist referral and MDT care – recommends that women with a high probability of Placenta Accreta Spectrum should have an antenatal care plan involving an expert multidisciplinary team and delivery in a specialist centre
- Ultrasound - updated guidance on the role of transvaginal ultrasound in evaluating placental position and cervical length
- Intraoperative cell salvage - now recognised as beneficial and safe for women with placenta praevia and Placenta Accreta Spectrum
- Patient involvement - greater emphasis on involving women and their partners in decisions around anaesthesia, pain management, and access to psychological support
Dr Alison Wright President of the Royal College of Obstetricians and Gynaecologists said:
“Placenta Praevia and Placenta Accreta Spectrum can cause serious complications during pregnancy and labour, so early risk detection and good clinical management is vital. The latest RCOG guideline reflects the most up to date evidence and provides best practice advice on the management and care of women with these conditions. The RCOG will be actively promoting the guidance to members, and we urge NHS Trusts to embed its recommendations into local practice, enabling multidisciplinary teams to offer the highest standard of care to every woman affected.”
Jane Plumb, Chair of the RCOG Women’s Network, said:
“Being told you have a condition such as Placenta Praevia or Placenta Accreta Spectrum can be frightening. Clear information, personalised advise helping make informed decisions, and feeling able to trust your care team all matter at that point. This new guideline, based on the best available evidence, will support clinical teams to offer safe, personalised and responsive care.”
Guideline process
The updated Green Top Guideline on the diagnosis and management of Placenta Praevia and Placenta Accreta Spectrum (GTG27a) commenced development in 2022, as part of RCOG's standard three-year review cycle.
In line with the RCOG guidance production process, the GTG27a update was informed by a review of the peer-reviewed evidence base, plus external peer review and public consultation. The GTG27a guideline development group comprised eight clinical experts, and the updated guideline was reviewed by the RCOG's Guideline Committee, which includes two patient and lay representatives.
About the conditions
Placenta Praevia happens when the placenta develops inside the lower part of the uterus partially or fully covering the cervix, blocking the birth canal. It is more common in women who have had a previous caesarean birth, fertility treatment or who smoke. The condition can cause heavy vaginal bleeding later in pregnancy and may mean the baby may need to be delivered via caesarean because the placenta may block the birth canal.
Placenta Accreta Spectrum is a serious complication of pregnancy where the placenta develops inside a scar of the uterine muscle and becomes abnormally attached. Placenta Accreta Spectrum is more common in women with Placenta Praevia who have previously had a caesarean birth, but it can also occur if you have had other surgery to your uterus, such as for fibroids, endometriosis or a termination of a pregnancy
- Read Placenta Praevia and Placenta Accreta Spectrum: Diagnosis and Management- GTG 27a, here.
- The guideline was updated as part of the standard review process of Green-top Guidelines. To read more about how the RCOG develops its Green-top Guidance: https://www.rcog.org.uk/media/4xyn1qmb/guidelinedevelopementguide-minor-update_final_march-_2025.pdf
- To find out more about the RCOG Maternity Safety programme available here.
- Read the RCOG maternity safety policy position here.