Which of the following best describes the events that occurred during the first stage of labor?

Labour has three stages:

The first stage of labour: dilation

Before labour starts, your cervix is long and firm. During the first hours of labour, the muscles of the uterus (womb) contract and help shorten and soften the cervix, so that it can dilate (open).

For first-time mothers, this stage can last from six to 36 hours.

During this time you might experience:

• Contractions - some can be quite mild, like a period pain; others can be sharp and strong. Initially, the contractions will be short (between 30 to 40 seconds) and irregular. Once contractions are five minutes apart and a minute or more in length, labour is said to be 'established'.

• A 'show' - the discharge of a plug of mucus that can be thick and stringy or blood-tinged. This may happen the day you go into labour, or up to a week before.
• 'Breaking of your waters' - this means the amniotic sac around your baby has ruptured.

Every labour is different. If you think you could be in labour, the first thing to do is relax and stay calm. The best place for early labour is at home.

When women who are planning to birth in a primary maternity unit or hospital stay at home until their labour is established, they are less likely to have interventions in their labour and are more likely to have a normal birth. 

Keeping yourself comfortable and supporting your labour to establish while you're at home.

Click here for information on things to do and try and home, and how to look after yourself during early labour. [PDF, 1.1 MB]

When to ring your lead maternity carer (LMC) or our Labour & Birthing Suite (if you are giving birth at Auckland City Hospital):

• Your contractions are coming every five minutes, lasting longer than 50 seconds and have been getting stronger for at least two to three hours.
• You have severe or constant abdominal pain with a tight abdomen.
• Your water has broken and it is clear or has a tinge of pink. Put on a sanitary pad and check it after an hour. If it is wet, please ring us.
• Your water has broken and it is green or brown. Call us immediately - you will be advised to come into hospital.
• If there is a change in the pattern of your baby's movements..
• You notice any vaginal bleeding - bright red vaginal bleeding is not normal.

Things to do and try at hospital:

• Try not to tense up during contractions. Your body is trying to release something, not tighten up.
• Find positions that feel comfortable. Walk the corridors slowly, lean on the walls, use the Swiss ball and La-Z-boy chairs. Try to stay off the bed, unless for a short rest.
• Water is great for relaxation and coping with contractions. If you don't have use of a pool, try the shower.
• Bring music and a player, if it relaxes or calms you.
• Bring an electric oil burner and use your aromatherapy oil.
• Continue to take refreshments and drink small amounts frequently.
• Phone calls are a distraction from your tasks of giving birth and looking after your new baby. Encourage family and friends to phone one designated person for updates.

The second stage of labour: your baby

The second stage of labour begins when the cervix is fully dilated (open) and the baby's head moves down out of the uterus and into the vagina (or birth canal). Your job at this stage is to push the baby through the birth canal, so you'll need focused determination and energy.

The birth of your baby may take 30 minutes to an hour or longer. This second stage could be further extended if you have an epidural.

A small number of women will require assistance with their births, either by forceps or ventouse (vacuum extraction). The obstetrician will choose which is best for your situation.

Find out more about your pain relief options and coping with labour.

The third stage of labour: the placenta

The final stage of labour is delivery of the placenta. There can happen in one of two ways listed below.

Your LMC can help you to decide which approach would be best for you, taking into considering your health, how your pregnancy has progressed and the type of labour and birth you experience.

1. Physiological management

Physiological third stage means waiting for your placenta to deliver spontaneously with your effort. This may take up to an hour following the birth; while you're waiting, skin-to-skin with your baby and a first breastfeed will be encouraged.

2. Active management

Active management involves injecting an ecbolic (contracting drug) into your leg as your baby's shoulders are born. The ecbolic speeds up placental separation and your uterus (womb) contracts down to reduce blood loss and ensure your womb remains contracted.  

Please read our leaflet on caring for your whenua [PDF, 1 MB] for more information.

Labor is a process that subdivides into three stages. The first stage starts when labor begins and ends with full cervical dilation and effacement. The second stage commences with complete cervical dilation and ends with the delivery of the fetus. The third stage initiates after the fetus is delivered and ends when the placenta is delivered. This activity outlines the stages of labor and its relevance to the interprofessional team in managing women in labor.

Objectives:

• Summarize the three stages of labor.

• Describe potential complications that may arise during each stage of labor.

• Identify what therapies may be targeted at the different stages of labor to result in better patient outcomes.

• Review the importance of accurate communication between the interprofessional team members regarding the stages of labor, leading to improved patient outcomes.

Labor is the process through which a fetus and placenta are delivered from the uterus through the vagina.[1] Human labor divides into three stages. The first stage is further divided into two phases. Successful labor involves three factors: maternal efforts and uterine contractions, fetal characteristics, and pelvic anatomy.[1] This triad is classically referred to as the passenger, power, and passage.[1] Clinicians typically use multiple modalities to monitor labor. Serial cervical examinations are used to determine cervical dilation, effacement, and fetal position, also known as the station. Fetal heart monitoring is employed nearly continuously to assess fetal well-being throughout labor. Cardiotocography is used to monitor the frequency and adequacy of contractions. Medical professionals use the information they obtain from monitoring and cervical exams to determine the patient's stage of labor and monitor labor progression.

Initial Evaluation and Presentation of Labor

Women will often self-present to obstetrical triage with concern for the onset of labor. Common chief complaints include painful contractions, vaginal bleeding/bloody show, and fluid leakage from the vagina. It is up to the clinician to determine if the patient is in labor, defined as regular, clinically significant contractions with an objective change in cervical dilation and/or effacement.[1] When women first present to the labor and delivery unit, vital signs, including temperature, heart rate, oxygen saturation, respiratory rate, and blood pressure, should be obtained and reviewed for any abnormalities. The patient should be placed on continuous cardiotocographic monitoring to ensure fetal wellbeing. The patient's prenatal record, including obstetric history, surgical history, medical history, laboratory, and imaging data, should undergo review. Finally, a history of present illness, review of systems, and physical exam, including a sterile speculum exam, will need to take place.

During the sterile speculum exam, clinicians will look for signs of rupture of membranes such as amniotic fluid pooling in the posterior vaginal canal. If the clinician is unsure whether or not a rupture of membranes has occurred, additional testing such as pH testing, microscopic exam looking for ferning of the fluid, or laboratory testing of the fluid can be the next step.[2] Amniotic fluid has a pH of 7.0 to 7.5, which is more basic than normal vaginal pH. A sterile gloved exam should be done to determine the degree of cervical dilation and effacement. The measurement of cervical dilation is made by locating the external cervical os and spreading one's fingers in a ‘V’ shape, and estimating the distance in centimeters between the two fingers. Effacement is measured by estimating the percentage remaining of the length of the thinned cervix compared to the uneffaced cervix. During the cervical exam, confirmation of the presenting fetal part is also necessary. Bedside ultrasound can be employed to confirm the presentation and position of the fetal presenting part. Particular mention should be noted in the case of breech presentation due to its increased risks regarding fetal morbidity and mortality compared with the cephalic presenting fetus. 

Management of Normal Labor

Labor is a natural process, but it can suffer interruption by complicating factors, which at times necessitate clinical intervention. The management of low-risk labor is a delicate balance between allowing the natural process to proceed while limiting any potential complications.[3] During labor, cardiotocographic monitoring is often employed to monitor uterine contractions and fetal heart rate over time. Clinicians monitor fetal heart tracings to evaluate for any signs of fetal distress that would warrant intervention as well as the adequacy or inadequacy of contractions. Vital signs of the mother are taken at regular intervals and whenever concerns arise regarding a clinical status change. Laboratory testing often includes the hemoglobin, hematocrit, and platelet count and is sometimes repeated following delivery if significant blood loss occurs. Cervical exams are usually performed every 2 to 3 hours unless concerns arise and warrant more frequent exams. Frequent cervical exams are associated with a higher risk of infection, especially if a rupture of membranes has occurred. Women should be allowed to ambulated freely and change positions if desired.[3] An intravenous catheter is typically inserted in case it is necessary to administer medications or fluids. Oral intake should not be withheld. If the patient remains without food or drink for a prolonged period of time, intravenous fluids should be considered to help replace losses but do not need to be used continuously on all laboring patients.[3] Analgesia is offered in the form of intravenous opioids, inhaled nitrous oxide, and neuraxial analgesia in those who are appropriate candidates.[4] Amniotomy is considered on an as-needed basis for fetal scalp monitoring or labor augmentation, but its routine use should be discouraged.[3] Oxytocin may be initiated to augment contractions found to be inadequate.

First Stage of Labor

The first stage of labor begins when labor starts and ends with full cervical dilation to 10 centimeters.[1] Labor often begins spontaneously or may be induced medically for a variety of maternal or fetal indications.[5] Methods of inducing labor include cervical ripening with prostaglandins, membrane stripping, amniotomy, and intravenous oxytocin.[5] Although precisely determining when labor starts may be inexact, labor is generally defined as beginning when contractions become strong and regularly spaced at approximately 3 to 5 minutes apart.[1] Women may experience painful contractions throughout pregnancy that do not lead to cervical dilation or effacement, referred to as false labor. Thus, defining the onset of labor often relies on retrospective or subjective data. Friedman et al. were some of the first to study labor progress and defined the beginning of labor as starting when women felt significant and regular contractions.[6] He graphed cervical dilation over time and determined that normal labor has a sigmoidal shape. Based on the analysis from his labor graphs, he proposed that labor has three divisions. First, a preparatory stage marked by slow cervical dilation, with large biochemical and structural changes. This is also known as the latent phase of the first stage of labor. Second, a much shorter and rapid dilational phase is also known as the active phase of the first stage of labor. Third, a pelvic division phase, which takes place during the second stage of labor.[1]

The first stage of labor is further subdivides into two phases, defined by the degree of cervical dilation. The latent phase is commonly defined as the 0 to 6 cm, while the active phase commences from 6 cm to full cervical dilation. The presenting fetal part also begins the process of engagement into the pelvis during the first stage. Throughout the first stage of labor, serial cervical exams are done to determine the position of the fetus, cervical dilation, and cervical effacement. Cervical effacement refers to the cervical length in the anterior-posterior plane. When the cervix is completely thinned out, and no length is left, this is referred to as 100 percent effacement.[1] The station of the fetus is defined relative to its position in the maternal pelvis.  When the bony fetal presenting part is aligned with the maternal ischial spine, the fetus is 0 station. Proximal to the ischial spines are stations -1 centimeter to -5 centimeters, and distal to the ischial spines is +1 to +5 station.[1] The first stage of labor contains a latent phase and an active phase. During the latent phase, the cervix dilates slowly to approximately 6 centimeters. The latent phase is generally considerably longer and less predictable with regard to the rate of cervical change than is observed in the active phase. A normal latent phase can last up to 20 hours and 14 hours in nulliparous and multiparous women, respectively, without being considered prolonged.[1] Sedation can increase the duration of the latent phase of labor.[7] The cervix changes more rapidly and predictably in the active phase until it reaches 10 centimeters and cervical dilation and effacement are complete. Active labor with more rapid cervical dilation generally starts around 6 centimeters of dilation. During the active phase, the cervix typically dilates at a rate of 1.2 to 1.5 centimeters per hour. Multiparas, or women with a history of prior vaginal delivery, tend to demonstrate more rapid cervical dilation.[1] The absence of cervical change for greater than 4 hours in the presence of adequate contractions or six hours with inadequate contractions is considered the arrest of labor and may warrant clinical intervention.[7] 

Second Stage of Labor

The second stage of labor commences with complete cervical dilation to 10 centimeters and ends with the delivery of the neonate. This was also defined as the pelvic division phase by Friedman. After cervical dilation is complete, the fetus descends into the vaginal canal with or without maternal pushing efforts. The fetus passes through the birth canal via 7 movements known as the cardinal movements.  These include engagement, descent, flexion, internal rotation, extension, external rotation, and expulsion.[1] In women who have delivered vaginally previously, whose bodies have acclimated to delivering a fetus, the second stage may only require a brief trial, whereas a longer duration may be required for a nulliparous female. In parturients without neuraxial anesthesia, the second stage of labor typically lasts less than three hours in nulliparous women and less than two hours in multiparous women. In women who receive neuraxial anesthesia, the second stage of labor typically lasts less than four hours in nulliparous women and less than three hours in multiparous women.[1] If the second stage of labor lasts longer than these parameters, then the second stage is considered prolonged. Several elements may influence the duration of the second stage of labor, including fetal factors such as fetal size and position, or maternal factors such as pelvis shape, the magnitude of expulsive efforts, comorbidities such as hypertension or diabetes, age, and history of previous deliveries.[8] 

Third Stage of Labor

The third stage of labor commences when the fetus is delivered and concludes with the delivery of the placenta. Separation of the placenta from the uterine interface is hallmarked by three cardinal signs, including a gush of blood at the vagina, lengthening of the umbilical cord, and a globular shaped uterine fundus on palpation.[1] Spontaneous expulsion of the placenta typically takes between 5 to 30 minutes.[1] A delivery time of greater than 30 minutes is associated with a higher risk of postpartum hemorrhage and may be an indication for manual removal or other intervention.[1] Management of the third stage of labor involves placing traction on the umbilical cord with simultaneous fundal pressure to effect faster placental delivery. 

The function of the stages of labor is to create a universal definition that medical professionals can use to communicate with each other about labor. The stages of labor can be used to help determine where the patient is on the labor spectrum. Clarifying the stages of labor has helped create guidelines, which define normal and abnormal trends in labor. Clinical management also gears toward the various stages of labor. 

Complications may arise during any of the stages of labor to result in abnormal labor. During the first stage, women may experience the arrest of parturition, necessitating cesarian delivery, which may carry greater maternal or fetal risk. Second stage complications include a variety of complications related to the trauma of the delivery process to either the fetus or the mother. The fetus can suffer acidemia, shoulder dystocia, bony fractures, nerve palsies, scalp hematomas, and anoxic brain injuries. Similarly, the mother can develop a host of traumatic complications ranging from uterine rupture, vaginal laceration, cervical laceration, uterine hemorrhage, amniotic fluid embolism, and death. The third stage of labor may encounter complications from hemorrhage, cord avulsion, retained placenta, or incomplete removal of the placenta.[5]

Defining the stages of labor with a specific beginning and end has allowed clinicians to study labor trends and to create labor curves. For example, in the 1950s, Dr. Friedman created a graphical representation of the rate of normal labor during latent and active labor using observed clinical data.[9] These, in turn, can be used to determine if a woman is progressing through labor as expected and helping to identify abnormal labor. Friedman observed that labor typically has a sigmoidal shape when measured by cervical dilation over time. During the active phase of labor, cervical dilation occurs at a rate of 1 centimeter or more per hour.  If dilation occurs much slower, the patient may be at risk for abnormal labor or arrest of labor.[10] 

If a woman is found not progressing through the first stage of labor as expected, this could lead to the diagnosis of the arrest of dilation or descent, which could result in cesarean delivery. The findings of Dr. Friedman have recently been challenged, and the current consensus is the normal latent phase of labor lasts longer than was previously observed.[8] The criteria for the stages of labor create a universal language that allows healthcare professionals to communicate with one another about patient care accurately. Also, specific interventions are tailored to particular stages of labor to try to create better patient outcomes. For example, active management in the third stage of labor is carried out by placing immediate traction on the umbilical cord and administering intravenous oxytocin, which correlates with a lower risk of postpartum hemorrhage.[11] Clinicians will continue to use the stages of labor to guide labor management and study labor patterns to improve patient care.

The stages of labor describe a complex physiologic process that starts when labor beings and ends with the delivery of the fetus and placenta. Labor is usually monitored clinically with multiple modalities by an interprofessional team. The process of labor can proceed as typically expected with certain cardinal events and time parameters or can encounter complications and delays, which may require identification and medical intervention.

The role of the interprofessional team in monitoring and caring for women during labor is critically important in keeping women safe and improving outcomes during the labor process.

A wide variety of medical professionals such as nurses, midwives, pharmacists, family physicians, anesthesiologists, and obstetrician/gynecologists may be involved in a woman’s labor process. Close communication is needed between these professionals to create an atmosphere of safety and patient-centered care. Midwives often manage labor and delivery and work closely with physicians when complications arise, requiring physician intervention, such as Caesarian section or operative delivery. Pharmacists ensure that patients receive the proper analgesics, tocolytics, and other medications that may be needed during or following labor. Anesthesiologists and nurse anesthetists administer epidurals for analgesia and are available for general endotracheal anesthesia when necessary. Nurses monitor the patient’s vital signs, contractions, cervical exams, pain scores, administer medications, recognize complications, and update the physician or midwife responsible for the patient. Each labor is unique, but an interprofessional approach prenatally and during labor can be used to improve patient outcomes and provide patient-centered care, as each provider class works collaboratively to ensure communication lines remain open between different disciplines on the health care team [Level 5]

A Canadian retrospective cohort study of 1238 women found that an interprofessional team approach to obstetrical care was shown to provide better patient outcomes by decreasing the rate of cesarian sections and length of hospital stays for women.[12] [Level 4]

Nurses are intimately involved in monitoring and caring for laboring women. Nurses administer and titrate medications during labor, such as oxytocin. Nurses monitor the vital signs, pain scores, and labor progression of women and fetuses closely and are responsible for recognizing and then notifying physicians and midwives when abnormalities arise.

Review Questions

1.

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Cheng YW, Caughey AB. Defining and Managing Normal and Abnormal Second Stage of Labor. Obstet Gynecol Clin North Am. 2017 Dec;44(4):547-566. [PubMed: 29078938]

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