Advanced maternal age at first delivery and long-term maternal risk for endocrine morbidity

Purpose: The incidence of women giving birth at advanced maternal age is increasing. Literature regarding the long-term implications of delivery at advanced maternal age is limited. This study aimed to investigate whether advanced maternal age at first delivery correlates with elevated long-term risk of endocrine morbidities. Methods: This retrospective population-based study included women who gave birth between 1991 and 2021. Participants were categorized by age at first delivery: < 30, 30–35, 35–40, and > 40 years. Women with pre-existing endocrine disorders before pregnancy were excluded. Kaplan–Meier survival curves assessed cumulative incidence of endocrine disorders, while Cox proportional hazards models calculated adjusted hazard ratios (HR), accounting for confounders including fertility treatments, ethnicity, gestational diabetes mellitus, and hypertensive disorders. Results: A total of 77,746 women were included. Advanced maternal age at first delivery was significantly associated with increased risk for endocrine morbidity, particularly diabetes and hyperlipidemia, both showing a clear age-related progression. No significant differences were observed for thyroid, parathyroid disorders, or obesity. Kaplan–Meier curves showed the highest endocrine morbidity risk among women delivering after age 40 (log-rank p < 0.001). After adjustment, hazard ratios were: 30–35 years aHR 1.29 (95% CI 1.19–1.40, p < 0.001), 35–40 years aHR 1.27 (95% CI 1.10–1.47, p < 0.001), and > 40 years aHR 1.15 (95% CI 0.86–1.54, p = 0.339), compared to women < 30 years. Conclusions: Advanced maternal age at first delivery is independently associated with an increased risk of long-term endocrine morbidity, particularly diabetes and hyperlipidemia. This graded association underscores the need for long-term follow-up and preventive care in these women.