Severe maternal morbidity in patients of advanced maternal age with and without metabolic syndrome

Abstract

Purpose

To estimate the burden of metabolic syndrome (MetS) on severe maternal morbidity (SMM) in women of advanced maternal age (AMA), quantify age-related escalation in SMM risk, and evaluate sociodemographic influences.

Methods

We retrospectively conducted a cross-sectional, population-level analysis of the Nationwide Inpatient Sample (Q4 2015–2019), a discharge-level database, to identify delivery hospitalizations among patients aged ≥ 35 years. MetS was defined by ICD-10 codes indicating ≥ 3 of the following: hypertension, type 2 diabetes, obesity, hypertriglyceridemia, or low high-density lipoprotein cholesterol. The primary outcome was SMM as defined by the Centers for Disease Control and Prevention; a secondary outcome excluded blood transfusion. Multivariable logistic regression adjusted for race, income quartile, primary payer, hospital characteristics, and substance use. Weighted adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were reported.

Results

Among 3.1 million delivery hospitalizations, 556,609 (17.8%) occurred in AMA patients; 12,188 (2.2%) experienced SMM and 6,528 (1.2%) experienced nontransfusion SMM. SMM was significantly higher among patients with MetS compared to  those without (7.37% vs 2.17%; nontransfusion SMM: 5.36% vs 1.16%). SMM rates increased with advancing age. After adjustment, MetS was associated with markedly increased odds of SMM (AOR 2.75, 95% CI 2.29–3.30) and nontransfusion SMM (AOR 3.59, 95% CI 2.90–4.44), both p < 0.001.

Conclusion

MetS is associated with SMM risk among AMA patients, independent of sociodemographic factors, with risk increasing further at older maternal ages. This study quantifies the disproportionate burden of MetS in this high-risk population.