Patterns of care for women with placenta accreta spectrum

Placenta accreta spectrum (PAS) is a spectrum of conditions in which the placenta is abnormally adherent and invades the uterine wall. This invasion can cause life-threatening hemorrhage and lead to significant adverse maternal outcomes. Numerous studies have shown an association between treatment of PAS at high volume, specialized centers and improved maternal outcomes; however, little is known about how these data have influenced practice.

The objective of the study was to examine the patterns of care for women with placenta accreta spectrum over time.

Data from New York Statewide Planning and Research Cooperative System (SPARCS) from 2000 to 2017 was used for this analysis. The study cohort comprised of women aged 15-54 years with PAS who underwent a hysterectomy during their delivery hospitalization. Study outcomes included severe maternal morbidity as defined by the Centers for Disease Control and Prevention, surgical complications, and transfusion. Hospitals were stratified into tertiles based on the volume of PAS hysterectomy cases. Patient demographic and clinical characteristics were compared across volume tertiles. Random intercept log-linear regression models with Poisson distributions and log link functions were fit to examine the association between hospital PAS volume and the outcomes of interest.

A total of 1958 women with PAS who underwent hysterectomy at 123 hospitals were identified. The number of hospitals providing care ranged from 46 centers in 2000 to 52 hospitals in 2016. The median hospital-level case volume of PAS was 1 (interquartile range [IQR], 1-2) in 2000 and rose slightly to 2 (IQR, 1-4) by 2016. The PAS volume cut-point for the top decile of hospitals was three cases in 2000 and increased to six cases in 2016. There was no significant change in the median travel distance for women with PAS over time. The rate of severe maternal morbidity increased significantly from 14.1% (95% CI: 7.8-24.0%) in 2000 to 19.0% (95% CI: 13.6-25.8%) in 2016. Transfusion occurred in 66.2% (95% CI: 54.6-76.1%) of cases in 2000 compared to 60.1% (95% CI: 52.3-67.4%) in 2016. Surgical complications occurred in 16.9% (95% CI: 9.9-27.3%) of cases in 2000 to 24.7% (95% CI: 18.6-32.0) in 2016. There was no difference in the adjusted rates of transfusion or surgical complications based on hospital volume. Compared to low-volume centers, the risk of severe maternal morbidity was reduced by 33% (aRR = 0.67; 95% CI: 0.50-0.90) at the intermediate volume centers.

There has been little change in the patterns of care for women with PAS in New York State. While the volume of patients with PAS has increased at the highest volume centers, a large number of relatively low-volume centers still provide care for a significant number of women with PAS.