Associations of Diabetes, Mental Health, and Asthma with Hypertensive Disorders of Pregnancy: A Population-based Case-Control Study in Alberta, Canada

Objective

To explore direct and indirect associations of diabetes, mental health, and asthma diagnosed before or during pregnancy with gestational hypertension (GH) or preeclampsia (PE).

Study design

This population-based case-control study conducted in Alberta, Canada, analyzed perinatal registry data from primiparous pregnant women aged 16 years and above, with no prior hypertension history, during the period 2010 to 2013. Cases of GH and PE were matched on gestational age with a random sample of controls at a 1:3 ratio.

Main outcome measures

We examined the presence of type 2 diabetes mellitus (T2DM) or gestational diabetes, depression, anxiety, and asthma diagnoses within five years before and during pregnancy. To estimate direct and indirect associations between these diagnoses and GH and PE, we used multivariable logistic and mediation models, adjusting for covariates.

Results

The analysis included 18,381 women (3,443 GH cases, 1,152 PE cases, and 13,786 controls). We found a direct association between anxiety during pregnancy and GH (adjusted Odds Ratio [aOR] 2.18, 95 % confidence interval (CI) 1.43–3.31). Depression before pregnancy increased the odds of anxiety during pregnancy (aOR 4.78, 95 % CI 2.89–7.92) resulting in an indirect effect on GH (aOR 3.63, 95 % CI 1.67––7.87). For PE, we observed direct associations with pre-pregnancy T2DM (aOR 1.58, 95 % CI 1.12–2.24), gestational diabetes (aOR 1.28, 95 % CI 1.04–1.56), and asthma during pregnancy (aOR 2.23, 95 % CI 1.41–3.51).

Conclusion

These findings highlight the interplay of mental health factors in influencing GH and underscore the clinical importance of diabetes and asthma in the pathogenesis of PE.