Global review reveals gaps in PAS guidelines

Global review reveals gaps in PAS guidelines | Image Credit: © khunkornStudio – © khunkornStudio – stock.adobe.com.

Additional research is needed to expand on placenta accreta spectrum (PAS) guidelines, according to a recent study published in JAMA Network Open.¹

A comprehensive multidisciplinary approach is needed to manage PAS. This involves multiple specialties such as obstetrics and maternal-fetal medicine, urology, surgical oncology, and advanced gynecologic surgery.² Therefore, standardized clinical practice guidelines (CPGs) are used to ensure the best possible outcomes.¹

“Although previous reviews have provided some comparisons between the main guidelines on PAS, a gap remains in systematically evaluating discrepancies and evidence across all CPGs, particularly concerning variations between high-income countries and low- to middle-income countries (LMICs),” wrote investigators.

Systematic review and expert panel

The systematic review was conducted to provide a comprehensive analysis of PAS guidelines. All CPGs published from January 1, 2014, to January 31, 2024, focusing on PAS or including recommendations related to cesarean delivery (CD) were included in the analysis.

Guidelines were identified through professional societies’ websites, medical databases, and cited references from relevant CPGs. Data was extracted by 2 independent reviewers, with conflicts resolved by cross-checking the original articles.

The extracted information was reviewed by a panel of 15 to 18 experts through 2 SurveyMonkey rounds. During the review, experts commented and revised recommendations and highlighted areas of disagreement.

There were 18 articles included in the final analysis, 14 of which primarily addressed PAS and 4 mainly focused on management of CD or postpartum hemorrhage. Recommendations specific to LMICs were reported in only 1 article.

Epidemiology and screening guidelines

An agreement rate of 75% was reported across the guidelines’ epidemiology sections. CD was recognized as a significant risk factor of PAS in all guidelines, with additional CD further increasing risk. Notably, a referenced source highlighted an odds ratio of 1.96 for PAS in patients with a prior CD vs no CD.

Additional risk factors discussed in the guidelines include prior myomectomy, minor uterine operations, and placenta previa or low-lying. However, these associations were supported by moderate to low evidence.

Inconsistent reports were noted for multiparity, multiple pregnancies, smoking, cocaine use, anemia, and other factors. For prenatal screening, an overall agreement rate of 76.9% was reported, vs a 7.7% disagreement rate and 15.4% insufficient evidence. Ultrasonography was unanimously recommended as the first-line method of PAS screening.

Second-trimester screening was most often recommended, though 3 guidelines recommended first-trimester initiation. Priority candidates included patients with known risk factors, but less agreement was reported for anterior low-lying placenta cases.

A 2013 meta-analysis was frequently cited. In the study, ultrasonographic sensitivity and specificity of 90.7% and 96.9%, respectively, were reported. Less agreement was found for magnetic resonance imaging, with some guidelines reporting value in certain scenarios but highlighting conflicting evidence.

Management guidelines

An agreement rate of 88.9% and insufficient evidence of 11.1% was reported for antenatal management across guidelines. No consensus has been reached about the optimal surveillance timeframe in patients suspected to have PAS. Variations were also noted in the recommended gestational age for inpatient admission.

The need to manage suspected PAS disorders and specialized disorders had unanimous agreement across the guidelines. Comprehensive counseling was also strongly recommended for patients considering fertility preservation in all guidelines. This is needed to ensure patients understand the risks associated with fertility preservation.

Evidence to definitively provide future pregnancy rates and whether to mention risks about intensive care unit admission and death remains insufficient in patients considering conservative management. However, all guidelines recommended the decision to receive conservative management should only be made after thorough counseling.

Limitations in current evidence

The review highlighted discrepancies and evidence gaps in vital areas of PAS identification and management. Investigators concluded there is a need for context-specific recommendations made with these resource limitations in mind.

“With PAS incidence increasing worldwide, prioritizing these research areas and developing comprehensive, globally applicable guidelines are essential steps toward improving outcomes for all patients affected by this life-threatening condition,” wrote investigators.

References

1. Bonanni G, Lopez-Giron MC, Allen L, et al. Guidelines on placenta accreta spectrum disorders: A systematic review. JAMA Netw Open. 2025;8(7):e2521909. doi:10.1001/jamanetworkopen.2025.21909
2. Shamshirsaz AA, Fox KA, Salmanian B, et al. Maternal morbidity in patients with morbidly adherent placenta treated with and without a standardized multidisciplinary approach. Am J Obstet Gynecol. 2015;212(2):218.e1-9. doi:10.1016/j.ajog.2014.08.019