Association between family health and fertility intention among women of childbearing age in China: evidence from a large multi-stage cross-sectional survey.

Background: Fertility has consistently been an imperative issue worldwide. Fertility intention plays a crucial role in predicting individuals' actual fertility behaviour. Family health may be effective in improving women's fertility intentions. However, the relationship between family health and fertility intention remains unclear. Therefore, we aimed to examine whether family health was associated with fertility intention among Chinese women of childbearing age. Methods: Using data from Psychology and Behaviour Investigation of Chinese Residents in 2021, we conducted a nationwide cross-sectional study in 1405 eligible women. Family health was measured using the Short Form of the Family Health Scale. Fertility intention was measured using a self-made questionnaire. We applied multivariate logistic regression and restricted cubic spline models to examine the association and dose-response relationship between family health and fertility intention. Subgroup analyses and interaction tests were further used to examine differences across strata. Results: After full adjustment, higher family health was associated with greater fertility intention (odds ratio (OR) = 1.07; 95% confidence interval (CI) = 1.03, 1.10), with consistent findings across quartiles. A linear dose-response relationship was observed (P for nonlinear = 0.724). Significant interactions by age and number of children were identified (P for interaction <0.001), with stronger associations among women aged 19-40 years without children. Conclusions: Family health is an important determinant of fertility intention, particularly among younger women without children. Therefore, public health policies aiming at enhancing fertility intentions should consider the importance of improving family health.