Pathway linking unwanted pregnancy to low birth weight in Indonesia: A conditional mediation analysis

Unwanted pregnancies resulting in detrimental consequences for both the mother and the child, including low birth weight, pose a remarkable challenge in developing countries. Although the association between low birth weight (LBW) and unwanted pregnancy is widely demonstrated, the results have been inconsistent, and the underlying mechanisms remain unclear. We examined maternal antenatal care (ANC) completeness as a potential mediating factor of the association between unwanted pregnancy and LBW among women in Indonesia, as well as the moderating effect of family support during pregnancy. We used women's records from the Indonesian Demographic and Health Survey (IDHS), a population-based survey conducted in 2017. This study involved 13,179 women aged 15–49 whose most recent child was aged 1–5 years. The multiple logistic regression results demonstrated that unwanted pregnancy was not associated with LBW. The generalized structural equation modeling (GSEM) results depicted that the effect of unwanted pregnancy on LBW was overwhelmingly explained by incomplete ANC, suggesting the mediation and suppression effect in the model (b = 0.32; 95 % Bias-corrected CI = 0.19–0.50; p = <0.001). The indirect impact of unwanted pregnancy on LBW also varied among different family support levels. This study filled the gaps in previous research on how unwanted pregnancy affects maternal and health outcomes. In conclusion, adequate ANC intervention and positive family support should be strengthened in future policy implementation to prevent the adverse effects of unwanted pregnancy.