Hour 18 Pregnancy Yoga – Birth Canal and Cervical Changes

Birth Canal and Cervical Changes

The cervix and birth canal are central to the labor and birth process. The anatomy and physiological changes of these structures during pregnancy are crucial for all who are supporting pregnant individuals, especially prenatal care, preparation for labor, and giving birth. The following chapter will discuss the pregnancy changes of the birth canal and cervix, and how these changes prime for an easy, healthy birth process

Anatomy of the Birth Canal

The birth canal is made up of multiple structures that collaborate to allow the baby through the birth process. They include:

Cervix: The lower portion of the uterus leading into the vagina. The cervix is the door to the uterus and helps protect the fetus during pregnancy. It also experiences dramatic changes to prepare for delivery.

Vagina: The muscular tube between the cervix and the external genitalia. The vagina dilates during labor to make room for the baby’s passage.

Pelvic Floor: The muscles, ligaments, and tissue that hold the uterus, bladder, and rectum in place. These same structures also stretch and support the passage of the baby during birth.

Cervical Changes During Pregnancy

During pregnancy, the cervix goes through some main changes that help it prepare for labor and delivery. These alterations are regulated by hormonal changes that happen in response to the expanding fetus and the imminent time of birth. The most important cervical changes are:

Softening: The cervix starts softening during early pregnancy as a result of hormonal changes, mainly the rise in estrogen. This softening is important for the opening of the cervix during labor.

Effacement: During preparation for delivery, the cervix effaces, meaning the cervix thins out. This makes the cervix more flexible and is necessary for the dilation process of labor. Effacement is quantified in percentages, with 100% effacement being the complete thinning.

Dilation: Dilation means the opening of the cervix. During labor, the cervix opens to enable the baby to travel through the birth canal. Dilation is quantified in centimeters, with 10 cm being fully dilated, which is required for the baby’s head to enter the birth canal.

Mucous Plug: During pregnancy, the cervix also creates a thick mucous plug that guards the fetus against infections. As labor begins, the cervix starts to dilate and efface and the mucous plug is ejected. This is also loosely termed as “losing the plug” and could occur days or even weeks prior to labor.

Birth Canal Changes During Labor

As labor progresses, the birth canal needs to stretch and expand to allow for the passage of the baby. The cervix further softens, effaces, and dilates. The vaginal tissues also become more elastic and lubricated as a result of heightened blood supply and changes in hormones. These changes are meant to assist in allowing the baby to descend and come out.

Pelvic Floor and Muscles: The muscles of the pelvic floor, which hold up the uterus and other organs, stretch and relax during childbirth. This opens up the space for the head of the baby to move through the birth canal.

Vaginal Expansions: The vaginal canal widens and becomes more elastic to accommodate the passage of the baby. The vagina enlarges with every contraction, facilitated by the release of hormones like relaxin, which cause the pelvis’s ligaments and muscles to relax.

Conclusion

The birth canal and cervix both experience dramatic anatomical and physiological alterations in pregnancy to prepare for giving birth. These transformations, such as softening, effacement, and dilation of the cervix, and the stretching and enlargement of the vagina and the muscles of the pelvic floor, are all essential to provide a safe passage for the baby. Awareness of these changes offers valuable information for pregnant individuals’ workers, allowing them to provide proper guidance and support throughout labor and delivery. The remarkable flexibility and adaptability of the cervix and birth canal illustrate the body’s natural ability to prepare for and navigate the complexities of childbirth.