Smooth delivery is a gradual process, when the uterine opening is full, it means that the fetus can be delivered quickly. So, how does the cervix develop step by step, and finally become "uterine opening"?
The uterus can be likened to a balloon, and the cervical canal is a balloon mouth, which has a certain length, and the balloon opening is the cervical opening. Only when the cervical opening is fully open (10 cm) can the fetal head pass through the full-term pregnancy.
The process of cervical change
Prenatal cervical canal disappearance:
The cervical canal is about 2.5-3 cm long, and the cervical canal of transposal women is slightly shorter than that of the first woman. When a pregnant woman begins to contract regularly, bursts of uterine contractions pull on the muscle fibers and ligaments of the inner orifice of the cervix. Coupled with the support of the fetal first exposed part, the cervical canal is pulled and formed like a funnel. But at this time, the external cervical opening does not change much. As the uterus contracts more and more intensely, the inner cervical opening is constantly pulled, and the cervical canal slowly begins to change from hard to soft. When the cervical canal softens, the cervical canal begins to shorten and then disappears.
Cervical canal changes in the first trimester have a certain development process, generally slow progression; while transposal cervical canal changes are often relatively fast, cervical canal shortening and disappearance are almost carried out together, at the same time, uterine orifice dilation is also carried out simultaneously.
Uterine dilation:
When the cervical canal is completely gone, the external cervical opening can only accommodate one fingertip, that is, the uterine opening is unopened. After delivery, the uterine opening gradually opens due to the upward pulling of the uterine contraction, the preludum exposure and the expansion of the anterior amniotic sac. From regular contractions to uterine opening, also known as the first stage of labor, the first stage of labor can be divided into incubation period and active period.
Incubation period: from regular contraction to 3 cm expansion of the uterine orifice. In this process, the progress of uterine orifice dilation is slower, with an average of 2-3 hours of expansion of 1 cm, a total journey of about 8 hours, and the longest generally does not exceed 16 hours.
Active period: After the pregnant mother has experienced the incubation period, it will enter the active period of uterine orifice dilation, that is, the process of uterine orifice dilation of 3-10 cm. This process accelerates the expansion of the uterine opening, taking about 4 hours to complete, and the longest generally does not exceed 8 hours.
When the uterine opening is complete, the fetus is delivered. Generally, the first time the mother takes about 1-2 hours, and the fetus can be born in just a few minutes, and generally the mother does not exceed 1 hour.
Note: If a pregnant mother who is not yet full-term, especially a pregnant woman before 34 weeks of pregnancy, has a short cervical canal or that the cervical canal has disappeared, it is especially necessary to pay attention to the contractions. When home fetal heart monitoring is found to be frequent, you should seek medical attention in time and ask a doctor to intervene to extend the pregnancy time as much as possible so that the baby can give birth at term.