Socio-demographic, family, and health-related predictors of maternal mental health trajectories during eight years postpartum in a national cohort of 17,886 mothers in Taiwan

Abstract

Background

Previous studies on maternal postpartum mental health are limited by non-representative samples, a narrow focus on mental illness, and a lack of systematic examination of predictors for diverse mental health trajectories. We investigated maternal mental health trajectories during eight years postpartum and their socio-demographic, family, and health-related predictors in a large cohort of mothers in Taiwan.

Methods

Participants were 17,886 mothers drawn from the Taiwan Birth Cohort Study (TBCS), a cohort study of a nationally representative sample of children born in Taiwan in 2005 and their parents. Maternal mental health was assessed at 6, 18, 36, 66, and 96 months postpartum using the Mental Component Summary (MCS) from the 36-item Short-Form Health Survey (SF-36) Taiwan version. We used group-based trajectory modeling to identify trajectory groups of maternal mental health and examined their predictors using multinomial logistic regression.

Results

Five postpartum mental health trajectories were identified: persistently poor (6.7%), improving (12.1%), deteriorating (14.3%), persistently moderate (46.7%), and persistently good (20.1%), with the first two groups having the poorest mental health at six months postpartum. Immigrant status and higher household income were associated with favorable (i.e., improving, or persistently moderate or good) mental health trajectories, while low family function and poor general health at six months postpartum were associated with less favorable (i.e., deteriorating or persistently poor) trajectories. Among mothers with poor mental health at six months postpartum, being divorced or separated was additionally associated with persistently poor mental health. Among mothers with moderate mental health at six months postpartum, being a first-time mother was additionally associated with deteriorating mental health.

Conclusion

Our findings highlight distinct maternal mental health trajectories over eight years postpartum, with one in five mothers experiencing deteriorating or persistently poor mental health. Socio-demographic factors, family function, and early postpartum health were predictors of these trajectories.