Childbirth Health Article

Definition

Childbirth includes both labor (the process of birth) and delivery (the birth itself); it refers to the entire process as an infant makes its way from the womb down the birth canal to the outside world.

Description

Childbirth usually begins spontaneously, following about 280 days after conception, but it may be started by artificial means if the pregnancy continues past 42 weeks gestation, or if complications develop. Labor may also begin prematurely. The average length of labor is about 14 hours for a first pregnancy and about eight hours in subsequent pregnancies. However, many women experience a much longer or shorter labor.

Labor can be described in a series of phases.

First phase of labor

During the first phase of labor, the cervix dilates (opens) from 0–10 cm (0–4 in). This phase has an early, or latent, phase and an active phase. During the latent phase, progress is usually very slow. It may take quite a while and many contractions before the cervix dilates the first few centimeters. Contractions increase in strength and frequency as labor progresses. Most women are relatively comfortable during the latent phase.

As labor begins, the muscular wall of the uterus contracts and relaxes as the cervix thins and expands. As a portion of the amniotic sac surrounding the baby is pushed into the opening, it bursts under the pressure, releasing amniotic fluid (water breaking). Sometimes the amniotic sac breaks before labor begins.

During this first phase the birth attendant or nurse will do periodic pelvic exams to determine how the labor is progressing. If the contractions aren't forceful enough to open the cervix, a drug called oxytocin (Pitocin) may be given to make the uterus contract.

As pain and discomfort increase, women may be tempted to request pain medication or anesthetics. If possible, though, these should be delayed until the active phase of labor begins—at which point the medication will not slow down or stop the labor.

The active stage of labor is faster and more efficient. In this phase, contractions are longer and more regular, usually occurring about every two to three minutes. These stronger contractions are also more painful. Women who use the breathing exercises learned in childbirth classes find that these can help them cope with the pain experienced during this phase. Many women also receive some pain medication at this point—either a short-term narcotic or epidural anesthesia.

As the cervix dilates to 8–9 cm (3.15–3.54 in), the transition phase begins. This refers to the progression from the first phase, during which the cervix dilates, to the second phase, during which the baby is pushed out through the birth canal. As the cervix dilates completely and the baby's head begins to descend, women feel the urge to push or bear down.