The soft birth canal includes the lower uterine segment, cervix, vagina and vulva. Lesions in the soft birth canal itself can cause obstructed labor, and lesions in and around other parts of the genital tract can also affect the soft birth canal and make labor difficult, but the former is more common. The obstructed labor due to soft birth canal abnormalities is much less common than that due to bony birth canal abnormalities, so it is easy to be overlooked, resulting in missed diagnosis. Therefore, vaginal examination should be performed routinely in early pregnancy to find out whether there are any abnormalities in the genital tract and pelvis. Since abnormalities of the soft birth canal can also cause obstructed labor, it is of clinical significance to perform a vaginal examination in early pregnancy to understand the condition of the vulva, vagina and cervix, as well as the presence of other pelvic abnormalities. The main causes are: 1. abnormal physical development, uterine dysplasia, short, small and long perineum, narrow vagina, long, small and hard cervical canal, lack of stretch and elasticity, and difficulty in opening wide during delivery. 2, senior primigravida A woman who is 35 years old or older is a senior primigravida. If you are married at the age of 35, you will have a different pregnancy than if you are married for 10 years and reach the age of 35. The former does not necessarily occur difficult delivery, the latter may occur due to poor development of reproductive organs delivery difficulties, general soft birth canal laceration formation of uterine prolapse chances increase. Because of the poor stretching of the pelvic floor muscle groups and muscle membranes in primiparous women in their senior years, the fetus can easily damage the pelvic floor muscles and muscle membranes when it passes, making it easy to form uterine prolapse.