Labor and Delivery
Labor and delivery is the process that transports the fetus from the uterus through the vagina (birth canal) and results in the birth of a baby. Signs and symptoms of impending labor are: lightening (the descent of the fetal head into the pelvis), softening of the cervix, Braxton Hicks contractions (contractions which occur that have no measurable effect on the cervix), bloody show (the expulsion of a mucus plug from the cervix), a spurt of energy, and increased gastrointestinal discomfort. The presence of contractions, which become regular and increase in frequency, intensity and duration is an important sign that labor has begun.
Labor is divided into four stages, briefly described below:
Regular contractions of the uterus cause the cervix to become thinner and the cervical os to open wider (dilation). Rupture of membranes (the amniotic sac containing the amniotic fluid breaks producing a gush of fluid) usually takes place during this phase. The first stage of labor continues from the onset of labor, until the dilation of the cervical os progresses to 10 cm.
In the second stage, the cervical opening has completely dilated (to 10 cm.) Contractions last longer and are more frequent. The woman is instructed to "push" while she experiences contractions, which facilitates the passage of the fetus through the cervix, and into the vaginal canal. The fetal head descends as the woman pushes the baby with each contraction. When birth is imminent, the head of the fetus can be seen (crowning). The second stage ends with the delivery of the baby.
The delivery of the placenta, membranes of the amniotic sac, and the umbilical cord (sometimes referred to as the afterbirth) occur during the third stage. The uterus continues to contract, which results in the separation of the placenta from the uterine wall. Placental delivery normally takes place within five minutes of infant delivery.
Marking the beginning of the post-partum period, the fourth stage takes place between one and four hours immediately following the delivery of the placenta. During this time, contractions of the uterus close off the blood vessels leading to the site of placental attachment.
There are many factors which contribute to decisions about obstetrical management during childbirth which include: maternal preference and health status, fetal maturity and health status, fetal position, the stage of labor, and maternal and fetal responses to the labor.
Interventions that monitor both fetal and maternal responses to labor include internal and external fetal heart rate monitoring, maternal blood pressure, and fetal scalp sampling.
Decisions about the use of pain medication and Pitocin (a synthetic hormone which enhances uterine contractions) are also made based on the clinical situation.
In the United States, many women take childbirth education classes in order to learn relaxation and breathing techniques learned during childbirth education classes. These techniques help to reduce anxiety and provide varying levels of pain relief.
At the time of delivery, the prenatal care provider may perform an episotomy, a surgical incision of the perineum (the area between the vagina and the anus) in order to prevent the tissues from tearing, and/or to expedite delivery. The incision is repaired following delivery.
A systemic review of the outcomes of routine episiotomy was published in JAMA in 2005, which concluded that the procedure does not demonstrate maternal benefits. In fact, the authors conclude that routine use more often causes injury rather than benefit to women. The study calls upon clinicians and other public health practitioners to track the prevalence of circumstances that do warrant use of episiotomy (i.e. fetal distress) and develop standards of care that optimize neonatal outcome and minimize maternal harm.
A Cesarean Section (C-Section) is a surgical procedure that allows for the birth of a baby through the abdomen instead of the vagina. C-Sections are performed in instances where vaginal delivery presents an unreasonable risk to the mother and/or the fetus (i.e. placental abnormalities, fetal position, disproportion between the size of the fetus' head and the size the woman's pelvis, and other medical problems including known HIV infection under certain circumstances). Complications related to C-Section are higher than those related to vaginal delivery, as with any surgery. C-Sections should be reserved for circumstances where the benefits outweigh the risks.
The post-partum period, also know as the puerperium, begins with the delivery of the placenta and last for six weeks following delivery. During this period, the uterus goes through a process called involution (reduction in the size of the uterus following childbirth). The uterus discharges a fluid called lochia (fluid containing blood and other fluids) for a period of two-to-three weeks. During the first two-to-three days, the lochia is red because it is filled with blood. As post-partum adjustment continues, the lochia becomes lighter in color.