How is cervical laxity caused?

Cervical laxity, that is, cervical dysfunction, it is due to congenital or acquired various reasons, cervical functional or cervical structural changes and defects, unable to support the pregnant uterus, and make the shape and function of the cervical orifice abnormal, resulting in non-delivery state of cervical pathological expansion, painless cervical regression, and ultimately abortion or premature birth. At this stage clear reasons are: congenital factors, acquired factors and infection factors. 1, congenital factors, accounting for about 1/3 of cervical insufficiency, congenital cervical insufficiency, often combined with abnormal development of the Muller canal, such as unicornuate uterus, septate uterus, double uterus, etc., in addition, there may also be cervical histological defects, such as collagen fiber reduction, collagen/smooth muscle ratio reduction, etc. 2, acquired factors, including mechanical damage, trauma and biochemical factors, mainly surgery and birth injury caused by cervical damage, especially mid-term pregnancy induced labor caused by cervical tissue damage, can also be secondary to cervical or lower uterine anatomical structure changes.3, infection factors, is also a factor that can not be ignored, as we all know, cervical local infection, but also an important cause of cervical dysfunction in the future.