Introduction
Although intrapartum hypoxia-ischemia is associated with cerebral palsy (CP), many CP cases’ etiology remains unknown.1A systematic review found that CP associated with intrapartum hypoxia-ischemia accounted for 14.5% of CP in developed countries, and the incidence of CP has persisted over the past 30 years.1 Placental and umbilical cord abnormalities are likely to induce fetal hypoxia, and the association between CP development and these abnormalities has been previously reported.2-4
The pathology of umbilical cord abnormality might be associated with its vulnerability to the external force during uterine contraction, resulting in acute intrapartum hypoxia-ischemia. However, the pattern and extent of deterioration in umbilical blood flow might vary depending on the type of umbilical cord abnormalities. A recently published nationwide study showed that the umbilical cord troubles were responsible for one-fourth of CP in term or near-term infants.5 This study also classified each CP case into five fetal heart rate (FHR) pattern categories. The FHR pattern evolution suggests the timing of fetal brain injury, which is expected to be critical considerations for the provision of safe delivery. Therefore, we focused on these notable features in elucidating CP associated with the umbilical cord troubles. We hypothesized that the FHR pattern evolution provides clues to prevent cord-related brain damage. The objective was to identify the FHR patterns in patients with CP associated with cord problems.