Advanced Maternal Age, Gestational Diabetes, and Parity: A Moderated Mediation Model for Preeclampsia

Abstract

Background:  As the trend of delaying pregnancy continues to grow globally, the prevalence of preeclampsia is expected to increase along with it, placing a significant burden on health systems. This study explores the mediating roles played by gestational diabetes and parity in the relationship between maternal age and preeclampsia.

Methods: This retrospective study considered 700 full-term pregnancies, with preeclampsia being the outcome of interest. Data were gathered from pregnant women at the El Idrissi provincial hospital in Kenitra, Morocco. We used Hayes' PROCESS macro model 7 (version 4.2) to analyze the direct effects and indirect effects in terms of moderated mediation while controlling for any family history of hypertension and hyperglycemia.

Result: The results show that gestational diabetes partially mediates the relationship between maternal age and preeclampsia with an indirect effect of 0.5275 (Boot SE = 0.2833, Boot CI%: 0.0151, 1.1258) for patients of advanced age and 0.8824 (Boot CI %: 0.0266, 1.7895) for those of very advanced age. In addition, parity moderates this relationship (advanced age x parity: β=0.2339, 95% CI: 0.1372, 0.3306; very advanced age x parity: β=0.2446, 95% CI: 0.0343, 0.4549). Finally, the mediating effect of gestational diabetes is also moderated by parity with a moderated mediation index of 0.4964 (Boot CI %: 0.0103, 1.1143) for patients of an advanced age and 0.5192 (Boot SE = 0.3677, Boot CI %: 0.0005, 1.4035) for those of a very advanced age.

Conclusion: A very advanced maternal age is an independent risk factor for preeclampsia. Multiparous women, especially older women, also have an increased risk of gestational diabetes, further increasing the risk of preeclampsia.