Objective. We report on the distribution of traditional Chinese medicine (TCM) constitution in the first trimester and on the association between TCM constitution and maternal symptoms related to pregnancy. Methods. Participants were followed up until delivery to observe primary measures (gestational hypertension and gestational diabetes mellitus) and secondary measures (signs of miscarriage, miscarriage, nausea and vomiting, and sleepiness and defecation during pregnancy). Descriptive analysis, t-tests, chi-square tests, and logistic regression analysis were used in this study. Results. 61.8% of the participants had unbalanced constitutions. We did not find a significant association between the TCM constitution and gestational hypertension, gestational diabetes, miscarriage, signs of miscarriage, and defecation during pregnancy. And we found that women with unbalanced constitutions in early pregnancy had a greater likelihood of severe nausea and vomiting and poor sleep during pregnancy in the logistic regression analysis. Conclusions. These results have implications for female health care providers and policy makers. Identification of TCM constitution may be helpful for understanding nausea and vomiting and poor sleepiness during pregnancy, especially in the condition that can not be explained by modern medical science, and be helpful for making program to improve these uncomfortable symptoms.