A systematic review of clinical guidelines showed wide variation and evidence gaps in the diagnosis and treatment of placenta accreta spectrum, a pregnancy complication associated with life-threatening hemorrhage. While experts largely agreed on diagnostic tools and antenatal management, recommendations varied in surgical approaches, conservative treatment, and postnatal care.
The researchers analyzed 18 articles from 14 national and international clinical practice guidelines published between January 1, 2014, and January 31, 2024. Only one guideline (5.6%) focused on low- and middle-income countries (LMICs), they reported.
Consensus was highest on managing placenta accreta spectrum (PAS) in specialist centers with multidisciplinary teams (100% agreement), antenatal management (88.9%), diagnosis (76.9%), and epidemiology (75%).
Previous cesarean delivery (CD) was consistently identified as a primary risk factor. One cited study reported increasing PAS incidence with the number of prior CDs: 0.2% after 1 CD, 0.3% after 2, 0.6% after 3, 2.1% after 4, 2.3% after 5, and 6.7% after 6 or more. Among patients with placenta previa, PAS incidence rose to 3.3%, 11.1%, 40%, 61%, and 67% for 1 to 5 prior CDs, respectively.
Ultrasonography with color Doppler was universally recommended as the first-line screening tool. Reported sensitivity was 90.7%, and specificity was 96.9%. Key sonographic markers included placental lacunae (77% sensitivity), loss of retroplacental clear space (66%), bladder border abnormalities (50%), and color Doppler abnormalities (91%).
Most guidelines recommended planned CD between 34 and 35 weeks’ gestation for patients with PAS. Corticosteroid administration was advised if delivery was expected before 35 weeks. However, timing of hospital admission and use of pharmacologic thromboprophylaxis varied across guidelines.
Surgical management, including cesarean hysterectomy, also showed poor consensus, the reviewers noted. Among 13 recommendations, 38.5% showed agreement, 38.5% had insufficient evidence, and 23% had disagreement. Variations were found in anesthesia choice, incision type, and the use of procedures such as ureteric stents and balloon occlusion catheters.
Conservative management recommendations were inconsistent. Of 30 related topics, 46.7% had agreement, 40% had insufficient evidence, and 13.3% had disagreement. Most guidelines discouraged forcible placental removal but differed on the acceptability of gentle removal. Leaving the placenta in situ was generally supported in select cases, although detailed monitoring protocols were lacking.
Postnatal care guidance was also limited. While 42.9% of recommendations aligned on components such as placental pathology review and referral to mental health services, 57.1% lacked sufficient evidence for iron supplementation strategies and thromboembolism prevention.
“The findings underscore the urgent need for further research and quality measures to enhance standardized approaches and improve patient outcomes,” wrote lead author, Giulia Bonanni, MD, of the Fetal Care and Surgery Center, Division of Fetal Medicine and Surgery at Boston Children’s Hospital, Harvard Medical School, with colleagues.
The researchers concluded that although global guidelines align on core diagnostic and antenatal practices, substantial variation persists in surgical, conservative, and postnatal care. The lack of guidance tailored to LMICs indicates a need for further research and standardized protocols to support clinical decision-making across diverse health care settings.
Full disclosures can be found in the published review.
Source: JAMA Network Open