The birth canal is the passageway a baby travels through during birth. It consists of the cervix, vagina, and vulva. During pregnancy, the baby grows inside the uterus. As labor begins, the cervix softens, thins, and opens, allowing the baby to pass through.
The cervix, located at the lower end of the uterus, acts as the entrance to the birth canal. During pregnancy, it remains closed to protect the baby. As labor starts, the cervix dilates (opens) and effaces (thins) to prepare for delivery. This process is known as cervical ripening.
Once the cervix is fully dilated (about 10 centimeters), the baby moves into the vagina. The vagina is a flexible, muscular tube that connects the cervix to the outside of the body. Its elasticity allows it to stretch wide enough for the baby’s head and body to pass through.
The Role of the Birth Canal in Delivery
Once the baby enters the vagina, contractions help push the baby downward. The baby’s head rotates and molds to fit through the mother’s pelvis. This molding allows the baby to safely navigate through the narrowest parts of the birth canal.
The vulva is the outermost part of the birth canal, and it’s where the baby’s head first becomes visible during delivery. As the baby’s head crowns (appears at the opening), the vaginal opening stretches to accommodate the baby’s head and body.
In some cases, a baby’s position or size can make delivery difficult. This can occur in breech, face, or transverse presentations. When this happens, a C-section may be necessary to ensure the safety of both the baby and mother.
After the baby is delivered, the placenta, or afterbirth, passes through the birth canal. This final stage of labor helps complete the delivery process.
In summary, the birth canal is the pathway a baby follows during vaginal birth. It includes the cervix, vagina, and vulva. These parts work together, stretching and opening to help the baby move through and enter the world.