Pregnancy is a long and critical period for most women and a period that has significant impacts for newborns. Many pregnancies have an increased risk for complications for a variety of reasons. Fortunately, early prenatal care and regular examination can help women have healthy pregnancies and deliver with fewer complications. However, current research shows that many expectant mothers do not have a clear understanding of the pregnancy process due to the complexity of medical information and inadequate attention from caregivers. Therefore, in this work, we collected data on expectant mothers' requirements and investigated the various medical treatments during pregnancy and the correlations between possible symptoms and newborn diseases. Based on the above knowledge, we then developed a visual analytic system named PregnancyLine, which presents a pregnancy care plan and information on the medical examinations at each pregnancy stage using a series of vivid visual metaphors. This system is designed to improve communication between pregnant women and doctors and help doctors identify patients with abnormalities and abnormal events. The results of the evaluation and case studies indicate that our system is effective in helping pregnant women understand pregnancy risk and the importance of examinations and that it is very useful in the detection and understanding of abnormalities.