The cervix is the organ that connects the uterus cavity with the vagina and performs certain functions. Its main function is protective, so due to tightly closed outer yawn it prevents penetration of flora from the vagina into the uterus. The cervix consists of the external and internal pharynx, and also the opening connecting the uterus with the vagina - the cervical canal. The normal length of the cervix during pregnancy should be at least 3 cm, with a decrease in its length, talk about the risk of abortion and decide whether to go on outpatient or inpatient treatment.
Cervical Length in Pregnancy
As already mentioned, the cervix performs a protective function, especially during pregnancy. In the early stages, it becomes very dense, it forms a slimy plug, which further prevents the penetration of infection into the uterine cavity. The length of the closed part of the cervix before the 36th week of pregnancy should be at least 3 cm. How long can the cervix be determined by a gynecologist during internal obstetric examination and ultrasound examination.
Cervical length by week
Specially conducted studies have revealed the dependence of the length of the cervix on the gestational age. So, the length of the cervix in the period of 10-14 weeks in the norm varies within 35-36 mm. At 15-19 weeks the length of the cervix is 38-39 mm, at 20-24 weeks - 40 mm, and at 25-29 weeks - 41 mm. After 29 weeks, the length of the cervix decreases and at 30-34 weeks is already 37 mm, and at 35-40 weeks - 29 mm. As you can see, after 29 weeks the cervix starts preparing for the forthcoming birth. After 36 weeks of gestation, the cervix begins to soften before birth , shortens, its pharynx starts to center and passes the tip of the finger. The length of the cervix in the re-born at 13-14 weeks should be 36-37 mm.
Cervical length before delivery
Immediately before birth, the cervix ripens, called "ripening." The neck is softened, centered (located in the center of the small pelvis), its length decreases to 10-15 mm, and the inner pharynx dilates by 5-10 mm (passes the tip of the finger or one finger). There is a smoothing of the inner part of the neck, it becomes, as it were, an extension of the lower segment of the uterus. The length of the cervix during childbirth rapidly decreases - it opens, so that the fetus can pass through the birth canal. On the beginning of labor is a cramping pain in the abdomen, which are called contractions. During the contraction, the uterine muscle fibers contract and at the same time the cervix opens. When the opening of the cervix reaches 4 cm, the labor activity is established and its subsequent opening occurs 1 cm per hour.
Length of cervix in case of threat of abortion
Reduction in the length of the cervix less than 30 mm at 17-20 weeks of pregnancy is regarded as istmiko-cervical insufficiency . With this pathology, the length of the cervix can be gradually shortened, and the fetus descends to the exit, which
We examined what should be the length of the cervix during pregnancy and before childbirth. And also got acquainted with such obstetric pathology as istmiko-cervical insufficiency, which can be said to reduce the length of the cervical canal less than 29 mm.