The presence of threads on the outside of the laceration wound may be due to incomplete absorption of the suture of the laceration wound in normal labor and delivery, loosening of the knot of the suture, or exposure of the suture on the outside of the laceration wound. Vaginal and perineal lacerations often occur during normal delivery, especially when there is maternal perineal edema, vaginal inflammation, fetal oversize, forceps delivery, etc., and even need to perform episiotomy suture. The laceration may be left unsutured if it is small and there is no active bleeding, but it is often sutured if there is active bleeding or if an episiotomy is performed. Perineal suture can be external or internal, external suture is often non-absorbable and needs to be removed after a few days, while internal suture does not need to be removed and can be absorbed on its own. However, some patients have poor absorption, which may result in residual knots, and some patients may have knots loosened during the absorption process, resulting in the threads being exposed. Patients with lacerations with threads are advised to consult a doctor to clarify the cause of the laceration and follow the doctor’s instructions for treatment.