Ovarian aperture failure in preterm infants can be a normal phenomenon, usually fusion occurs at 5-7 months of age, most do not require treatment, and the prognosis is good with aggressive treatment. In preterm infants, non-closure of the foramen ovale is normal and fusion usually occurs between 5 and 7 months of age, but may occur relatively late in preterm infants. If fusion has not occurred by 1 year of age, the diagnosis of patent foramen ovale is made. In the majority of cases of patent foramen ovale, there are no other abnormalities that require treatment, and the prognosis is good for aggressive treatment of cryptogenic stroke, venous thrombosis, and increased atrial pressure at a later stage of life. To summarize, preterm infants with patent foramen ovale is not very harmful, so there is no need to be too anxious. Regular follow-up is sufficient. Daily care of preterm infants should pay attention to keep warm, timely supplementation, breastfeeding as much as possible.