Prevalence of abnormally invasive placenta among deliveries in mainland China: A PRISMA-compliant Systematic Review and Meta-analysis

BACKGROUND: Abnormally invasive placenta (AIP) or placenta accreta (PA) is considered numerous adverse maternal and fetal-neonatal complications. There has been no detailed study to characterize the prevalence of AIP among deliveries in mainland China. OBJECTIVES: We aimed to fill this gap and obtained overall and regional estimates of AIP prevalence via a systematic review and meta-analysis. METHODS: This systematic review and meta-analysis was totally performed following the Meta-analysis of Observational Studies in Epidemiology guidelines for systematic reviews of observational studies, and the Preferred Reporting Items for Systematic reviews and Meta-Analysis statement for reporting systematic reviews and meta-analysis. RESULTS: A total of 23 articles (including 350,939) were included. Most studies (22) focused on the placenta increta (PI), only 2 articles in PA, and none in placenta percreta (PP). In this meta-analysis, the overall prevalence of AIP was 0.22% (95% confidence interval 0.18%–0.27%) in a heterogeneous set of studies (I(2) = 93.5%). In a subgroup, the prevalence of PA and PI was 0.48% and 0.23%, respectively. Stratified analyses of PI found that the prevalence was similar in North (0.23% [0.14%–0.32%]) and South (0.23% [0.15%–0.32%]), and lower in Central (0.20% [0.09–0.31%]); the inlanders (0.17% (0.12%–0.23%]) had a lower prevalence of PI than those living in coastal areas (0.24% [0.35%–0.63%]). As time goes on, the prevalence, from 0.03% (0.02%–0.04%) in 1970 to 1979 to 0.48% (0.30%–0.66%) in 2010 to present, was higher and higher. The different prevalence was also found in different in maternal age groups. CONCLUSIONS: This first systematic review and meta-analysis found that the prevalence differed among different geographic areas and maternal age groups. The results would be useful for the design of abnormally invasive placenta planning and implementation adequate health care systems and treatment programs in mainland China.