Mental Health
Modifiable Lifestyle Factors for Perinatal Depression among Women with a History of Premenstrual Disorder: A Nationwide Register-Based Study in Sweden Jane Yan* Jane Yan Donghao Lu
Background: Perinatal depression (PND) is a major depression episode that occurs during pregnancy or postpartum. Recently, our work has identified that women with premenstrual disorder (PMD) are at high risk of PND, potentially due to the vulnerability to hormonal fluctuations. However, little is known about risk factors modifying the risk of PND in this high-risk group – women with PMD.
Aim: The study aims to estimate the risk of PND associated with modifiable lifestyle risk factors (smoking, snuff use, BMI) comparing women with and without PMD.
Methods: We conducted a prospective cohort study of all women who gave birth during 2003-2021 in Sweden. PMD diagnosed before pregnancy and PND (depression diagnosed during pregnancy or within one year postpartum) were identified from National Patient Register and regional primary care registers. Lifestyle risk factors in early pregnancy, including smoking, snuff use, and maternal BMI was obtained from the Medical Birth Register. Log-binomial regressions with robust estimator were used to calculate Risk Ratio (RR) of PND associated with individual lifestyle exposure, stratified on women with and without PMD, with adjustment for demographic and pregnancy characteristics and history of psychiatric disorders.
Results: In total, 1,236,980 women (2,195,838 pregnancies) were included in the study, with 22,914 (1.85%) diagnosed with PMDs before pregnancy. Compared to women without PMD, women with PMD were more likely to be born in Sweden, have a higher education attainment, and have a history of psychiatric. Among women without PMD, smoking or snuff use in early pregnancy was associated with 20-36% increased risk of PND when comparing to no use, while no pronounced association was found across BMI categories. Compared to women without PMD, women with PMD were at about two-fold risk of PND, independent of psychiatric history. Exposure to tobacco use moderately altered the association (e.g., RR changed from 2.06 (95%CI 2.01-2.12) (no smoking) to 1.75 (95%CI 1.40-2.17) (≥10 cig/day), whereas a 44% reduction of RR was observed from overweight/obesity (RR 2.17/2.18, 95% CI 2.08-2.27/2.05-2.31) to underweight (RR 1.74, 95% CI 1.42-2.13) in early pregnancy. Similar trends were noted regardless of psychiatric history, although among women without psychiatric history PMD was associated with about eight times higher risk of PND.
Conclusion: Women with PMD, particularly in absence of psychiatric history, were at high risk of PND. Such risk may be modified by body adiposity, but not by tobacco use, although future studies are warranted to confirm the causal relationship.