Labor and delivery definitions and facts
Every woman's experience is unique. Below are typical guidelines that will help you understand what to expect during labor and delivery.
- Normal labor can begin three weeks prior to the anticipated due date up until two weeks afterwards.
- There is no way to precisely predict when labor will begin.
- In the first stage of labor the cervix dilates and effaces (thins out). Once contractions begin, they usually increase in strength, duration, and frequency.
- The second stage of labor begins when the cervix is completely (i.e. 10 centimeters) dilated. It ends when, following expulsive efforts (pushing) by the mother, the infant is delivered.
- During the third stage of labor, the placenta and membranes are delivered.
- There are a number of methods for monitoring the fetus that may be used during labor.
- Options for pain control during labor include breathing exercises, imagery, relaxation techniques, medications, and regional anesthesia.
What are the signs of labor and delivery?
Signs and symptoms of impending labor are not uniform among all women.
Lightening is a term used to denote the descent of the fetal head into the pelvis as labor approaches. It can occur up to two weeks prior to the onset of labor, or it may not occur at all. At that time, there may be increased pressure on the maternal bladder accompanied by the urge to urinate more frequently. Many women find it easier to breathe after lightening occurs because upward pressure on the diaphragm diminishes.
Release or passage of the "mucus plug" can be another sign that labor is near. Mucus produced by the cervical glands normally blocks the entrance to the cervix and helps prevent infection. When the fetal head impinges on the cervix, mucus from the cervical glands, along with a small amount of blood, is expelled. This results in a blood-tinged or brownish discharge being expelled from the vagina. Passage of the mucus plug may occur days before or after labor begins. It is also common after a vaginal examination.
Spontaneous rupture of the fetal membranes is referred to as one's "water breaking." This means that the membranes that surround the baby have ruptured, and clear amniotic fluid is often expelled from the vagina at that time. Once this occurs, labor will generally ensue spontaneously. If it does not, induction of labor may be necessary to avoid infection ascending upward through the vagina into the uterus. Most commonly rupture of the membranes does not occur until labor has already begun.
Finally, labor begins with the onset of contractions. At that point, the cervix begins to thin out and dilate. When contractions begin to occur less than ten minutes apart, this frequently signals the onset of labor. Irregular contractions, known as Braxton-Hicks contractions or "false labor," occur toward the end of pregnancy during the third trimester, and they do not necessarily signify that labor is imminent. Some women even experience these contractions during the second trimester. Braxton-Hicks contractions are usually milder than those of true labor are, and they do not occur at regular intervals.
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Braxton Hicks Contractions (False Labor) vs. Labor Contractions
Braxton-Hicks contractions "false labor" are uterine contractions that predominantly occur during the third trimester of pregnancy. Usually, labor contractions are more painful than Braxton-Hicks are.
What are the stages of labor and delivery?
Labor is divided into three stages; corresponding to the dilation of the cervix, the birth of the baby, and the delivery of the placenta.
Stage 1 of labor and delivery
Stage 1 is the longest stage of labor. It is characterized by thinning (effacement) and dilation of the cervix. Sometimes doctors subdivide this stage into three separate phases: the latent phase, the active phase, and the transition phase. Contractions, occurring with increasing frequency, are present during all phases of Stage 1. Early contractions last from 30 to 45 seconds and are several minutes apart. During the latent phase, the cervix dilates to about 3 to 4 centimeters. Many women are admitted to the hospital during this phase. In the active phase, the cervix dilates to about 7 centimeters, and the contractions become more intense. During the transition phase, the cervix dilates completely to 10 centimeters, and the contractions are strong and painful. Contractions can occur every 3 to 4 minutes and last from 60 to 90 seconds.
Stage 2 of labor and delivery
Stage 2 refers to the passage of the baby through the birth canal until delivery. It begins when the cervix has fully dilated and voluntary pushing is initiated. Sometimes this is referred to as the "pushing" stage. The head is typically delivered first, and sustained pushing allows for delivery of the infant's shoulders and body. Some women prefer different body positions during this stage of labor. These may include kneeling, squatting, lying down, or even on the hands and knees. This stage may take minutes to a few hours. According to the American College of Obstetricians and Gynecologists (ACOG), a woman giving birth for the first time should complete Stage 2 within 2 hours if no regional anesthesia has been used, and up to 3 hours if she has received anesthesia. Stage 2 is usually shorter in subsequent pregnancies, up to 2 hours if anesthesia has been given and 1 hour if none has been used.
Stage 3 of labor and delivery
Stage 3 begins at the time the infant is delivered. In stage 3, the placenta and fetal membranes are expelled. The placenta and membranes are sometimes referred to as the afterbirth. Stage 3 usually takes only 5 to 10 minutes, but it can take up to 30 minutes. Mild contractions may occur during stage 3, and there may be some associated bleeding.
What are pain control options during labor and delivery?
Many women opt not to receive medications or interventions for pain control during labor and delivery, while others choose medical or procedural pain control methods. Several different opioid analgesic and opioid agonist medications are acceptable for pain control. Examples are
Regional anesthesia is another option. This can be administered as an epidural, spinal, or combined spinal-epidural block. Research has shown that regional anesthesia is more effective than injectable medications for controlling pain. Moreover, large-scale clinical trials did not show an increase in the C-section rate in women who opted for regional anesthesia.
Women who choose not to receive pain medications can use breathing techniques and/or imagery for pain control. Relaxation techniques and yoga have also proved beneficial.
What kind of monitoring is done during labor and delivery?
- During the first stage of labor, you will likely have pelvic examinations to check the dilation and thinning of the cervix.
- The baby's heart rate is usually checked intermittently with a Doppler device, or continuous electronic fetal monitoring may be employed.
- External fetal monitoring is accomplished by placing a transducer on the maternal abdominal wall. The transducer detects the fetal heart rate and displays it on a visual tracing.
- Internal monitoring is another method used to follow the fetal heartbeat. With this technology, a small electrode is passed through the cervix and attached to the fetal scalp.
- The type of monitoring selected depends upon a number of factors, and it will vary from patient to patient. Your health-care professional will choose the most appropriate type for your individual situation.
- Continuous fetal monitoring is almost universally used if the woman receives epidural anesthesia, or if oxytocin (Pitocin) is used to induce labor. It is also employed with high-risk pregnancies or if the labor is complicated.
Medically Reviewed on 7/9/2018
Cheng, Y. et al. "Normal Labor and Delivery." Medscape. Updated: Nov 16, 2017.