Vaginal delivery, or the natural birth process, is the birth or delivery of a child through a woman's birth canal and vagina. Most births occur this way. Some women, however, opt for a surgical delivery, or Caesarean section, rather than birthing their children via vaginal delivery. A surgical delivery may be necessary if there are complications that can endanger the mother or child.
Labor can be divided into three stages — pre-birth, birthing, and after birth. While the first stage can be the longest, it often varies in duration, depending on the woman. During pre-birth, the mother’s cervix starts to dilate and efface, and the birth canal shortens. Effacing refers to the thinning of the cervix. The cervix is the lower part of the uterus, which connects with the vagina, or birth canal. This stage may involve discomfort and pain but the longer this stage takes, the less noticeable these changes may be.
Pre-birth can be subdivided into three stages, usually called the early, active, and transitional stages. The early stage is typically the longest and is the start of cervix dilation and effacement. The active stage is the longest part of pre-birth.
The active stage of labor generally involves the cervix becoming dilated to between 1.18 inches (3 cm) to 1.57 inches (4 cm), and — if a woman's water breaks — it usually occurs during this stage. Contrary to popular belief, a pregnant woman’s water, which is also known as the sac of amniotic fluid, will only break on its own about 15% of the time. Rupturing of the sac often requires the help of a doctor. The pain associated with contractions is often exacerbated by this rupture because the fluid can act as a buffer.
The final part of pre-birth, called the transitional stage, is typically the shortest and most painful. At this stage the contractions are usually close together, about two to three minutes apart. The cervix becomes fully dilated, to between 3.15 inches (8 cm) to 3.937 inches (10 cm). When this happens, the woman's body is ready for vaginal delivery.
The second stage of labor is characterized by the descent of the infant into the birth canal, and the actual vaginal delivery. The mother usually feels the urge to bear down, which is similar to a bowel movement feeling. Due to this, with each contraction, the mother will typically push for about ten seconds. With each push, the baby will slowly move forward.
As the head nears the vaginal opening, the mother may feel intense pressure. When the head starts to appear, or crown, at the vaginal opening some precautions are usually taken. To prevent tears to the perineum — the area between the vagina and the anus — the attending doctor, midwife, or nurse may massage the area to help ease the baby’s head out. In some cases, a small incision may be made to allow the head through. After the head is passed through, the rest of the baby is generally pushed through the birth canal and vaginal delivery of the child is completed.
The third and final stage of labor is usually the vaginal delivery of the placenta, or afterbirth. During pregnancy the placenta, which connects the mother to the baby, provides nourishment for the growing fetus. After the child has been delivered, the umbilical cord connecting the child to the placenta is clamped and severed. The placenta must then be expelled from the womb, which can take some time to accomplish. Some intuitions will manually deliver a placenta if it is not expelled within two hours after the birth.