Unintended pregnancy-related factors and the occurrence of offspring congenital heart disease: a multi-site case-control study in China.

OBJECTIVES The aim of this study was to explore the association between unintended pregnancy and related factors among congenital heart defects (CHDs) in infants. METHODS A total of 1197 cases with isolated CHDs and 1125 controls without any abnormalities were analysed in this multicentre study at seven hospitals in China. According to the pregnancy intention, cases were divided into two groups: planned and unintended pregnancies. The adjusted odds ratio (AOR) was calculated by logistic regression analysis to assess the association between unintended pregnancy and CHD occurrence. The time to prepare for pregnancy and the influencing factors were also compared in this article. RESULTS The risk for CHD occurrence was significantly associated with unintended pregnancy (AOR: 1.42; 95%CI: 1.16-1.73), which may increase the risks for each subtype of CHD occurrence. Risks such as parental smoking, housing renovation, accidental alcohol consumption, lack of health check-ups, and no folic acid supplementation before pregnancy were distributed differently among the planned and unintended pregnancy groups and were associated with CHD occurrence. However, there was no significant association between the duration of planned pregnancy and the risk of CHDs. CONCLUSIONS Unintended pregnancy increased the risk of CHDs in infants. This risk may be related to some known and unknown factors. SYNOPSIS Some unintended pregnancy related factors may increase the risk for foetal CHDs. The duration of planning pregnancy may not be associated with the risk of CHDs.