We empirically analyze the effects of psychological factors, such as the fear of parenting, on fertility rates. An index is calculated based on the share of negative news articles on child care in all social articles from 2000 to 2018. The analysis result shows that as the index increases, the fertility rate after three years falls. This result is repeated in the correlation analysis, simple regression, and VAR analysis. According to Granger causality analysis, it is found that the relation between the index and the fertility rate after three years is not just a simple correlation but a causal relationship. There are differences among age groups. The fertility rate of women in their 20s and 30s shows a significant response to the index, but that of the 40s does not. The index affects the birthrate of first child, but do not affect the birthrate of second or more children. These results are consistent with the intuition that younger women are more likely to be affected by the negative articles about parenting, but not to those who have already experienced childbirth. This study is meaningful in that a significant index for predicting social phenomena is extracted beyond the limited use of news big data such as a simple keyword mention volume monitoring. Also, this big data-based index is a 3-year leading indicator for fertility, which provides the advantage of providing information that helps early detection.