(129) Basal Plate Myometrial Fibers and Risk of Placenta Accreta Spectrum in Subsequent Pregnancies: A Meta-analysis

Basal plate myometrial fibers (BPMF) refer to the histopathologic finding of myometrial fibers attached to the basal plate of the placenta, with or without intervening decidua. This systematic review was undertaken to determine whether the presence of BPMF on placental pathology is associated with increased risk of Placenta Accreta Spectrum (PAS) and need for peripartum hysterectomy in subsequent pregnancies.

Study Design:
A systematic review of several databases was performed to identify studies reporting BPMF on placental pathology with a subsequent livebirth that also had placental pathology report. The study protocol was registered in PROSPERO (CRD420251103171). Statistical analysis was conducted using STATA, with pooled prevalence of PAS and peripartum hysterectomy as primary outcomes.

Results:
Of 167 articles retrieved, three met inclusion criteria including 278 patients who had BPMF during their previous pregnancy. The pooled prevalence of PAS in subsequent pregnancies for this cohort of patients was 8% (95% CI: 0.00–0.17, I² 83%). The prevalence of peripartum hysterectomy was 10% (95% CI: 0.08–0.29, I² 79%).

Conclusion:
These findings suggest that, following a prior diagnosis of BPMF in the index pregnancy, the prevalence of PAS and the need for peripartum hysterectomy in a subsequent pregnancy are approximately 8% and 10%, respectively.