Maternal dilation process

The technical name for opening the cervix is ​​cervical dilation. When a pregnant woman is about to give birth, her uterus contracts regularly, stretching the uterine muscles and surrounding fibers at the internal os of the cervix. In addition, the amniotic sac of the pregnant woman becomes wedge-shaped in front of the fetal presenting part, causing the internal os of the cervix to expand upward and outward, and the cervical canal gradually shortens until it disappears. The external os of the cervix is ​​usually only the size of a fingertip. As the labor progresses, the external os of the cervix expands to a diameter of 10 cm, allowing the head of a full-term fetus to pass through. This process is called dilation.

Introduction to Kaigongkou

The technical name for opening the cervix is ​​cervical dilation. The female cervical canal is a muscular tube about 2 cm long, connecting to the vagina on the outside and the uterus on the inside.

Opening of the cervix Opening of the cervix process

The process of cervical dilation is relatively slow. Generally, the cervix will slowly dilate in the second week after the ninth month of pregnancy, which is also the process of cervical formation. Your cervix dilates to 10 cm when the newborn is born. It is slow at the beginning. It takes an average of 8 hours from delivery to the cervical dilation of 1 cm, and an average of 4 hours from the cervical dilation of 3 cm to 10 cm. Generally, some medicines will not be used for pain until the cervix has dilated to one centimeter. It indicates that the pregnant woman has entered the active stage of labor. The cervix has already dilated to 3 cm, the cervix has become loose, soft, and quite elastic, and each uterine contraction is 2-3 cm. After delivery, the cervix will gradually dilate with regular uterine contractions. The first stage of labor is divided into two phases according to the degree of cervical dilation: the latent phase and the active phase. The latent phase is when regular uterine contractions occur until the cervix dilates to 3 centimeters, and the active phase is when the cervix dilates from 3 centimeters to 10 centimeters [1]. It should be pointed out here that the rate of cervical dilation is different for primiparas and primigravidas. In primiparas, the cervix first contracts and expands, and then the cervix expands; while in primiparas, the cervix contracts, expands, and expands at the same time. Therefore, the labor speed of primiparas is significantly higher than that of primiparas, which is also the key reason why the progress of the first stage of labor is different between primiparas and primiparas. The cervical dilation is slow during the latent phase and accelerates significantly during the active phase. The latent period for primipara is about 8 hours. The rate of primipara is faster than that of primipara, but there are great differences among individuals. The length of the latent period varies from person to person, ranging from tens of minutes to several hours. The active period of primipara takes about 4 hours. After entering the active period, primiparas should prepare for delivery, because the cervix of primiparas usually fully dilates soon after entering the active period.

How to check for dilatation of the cervix

1. After the baby enters the pelvis, the birth canal is ready, and the pregnant woman's vagina will naturally relax and open.

2. The doctor can check the degree of dilation of the cervical opening by observation.

3. The doctor can also use digital rectal examination to explore the condition of the cervical opening. Generally, the anus or vagina is examined. The doctor, wearing sterile gloves, inserts his fingers into the vagina and puts them on the cervical opening to accurately measure the opening of the cervical opening. Anal examination is only done when the pregnant woman is about to give birth, because the cervical opening in the vagina is very close, and there is a relatively thin retroperitoneum in the middle. Anal examination is to detect the opening of the cervical opening through this place. Regardless of whether the cervix is ​​dilated or not before delivery, repeated vaginal exploration will lead to iatrogenic infection, so digital rectal examination is used to distinguish it.