Global burden, trends and inequalities of maternal hypertensive disorders among reproductive-age women of advanced maternal age, 1990-2021: a population-based study.

Background: Maternal hypertensive disorders (MHD) are leading causes of maternal morbidity and mortality worldwide, particularly among reproductive-age women of advanced maternal age (AMA), representing a significant global public health challenge.

Objective: This study aimed to analyze the global trends, inequalities, and disparities in the burden of MHD among reproductive-age AMA women from 1990 to 2021.

Methods: We conducted a population-based study using data from the Global Burden of Disease (GBD) 2021 study, covering 204 countries and territories. The study included women aged 35-49 years with hypertensive disorders during pregnancy. We assessed age-standardized incidence rate (ASIR) and age-standardized death rate (ASDR) of MHD among reproductive-age AMA women. Temporal trends were evaluated using joinpoint regression analysis, while health inequalities were measured using the concentration index and the slope index of inequality (SII).

Results: Between 1990 and 2021, the global ASIR of MHD decreased from 568.10 (95% UI: 412.06-738.55) to 491.49 (95% UI: 368.78-619.84) per 100,000 population (AAPC: -0.46%, 95% CI: -0.54% to -0.38%), and ASDR declined from 2.57 (95% UI: 2.23-2.97) to 1.44 (95% UI: 1.19-1.76) per 100,000 population (AAPC: -1.83%, 95% CI: -1.99% to -1.67%). Substantial disparities persisted across socio-demographic index (SDI) regions, with high and high-middle SDI regions showing increasing incidence trends (AAPC: 2.36% and 1.45%, respectively). The slope index of inequality (SII) for ASIR improved from -3,052.73 (95% CI: -3,329.55 to -2,775.91) to -1,209.36 (95% CI: -1,393.12 to -1,025.61) per 100,000 women, while the SII for ASDR decreased from -11.29 (95% CI: -12.38 to -10.20) to -3.66 (95% CI: -4.13 to -3.20) deaths per 100,000 women. The concentration index for ASIR showed slight improvement (from -0.46 to -0.34), while ASDR inequality marginally worsened (from -0.62 to -0.66).

Conclusion: Despite overall declines in MHD burden, significant disparities persist, particularly in low SDI regions. These findings highlight the need for targeted public health interventions to reduce inequalities, improve healthcare access, and enhance maternal outcomes for reproductive-age AMA women globally.