What is childbirth
Childbirth | Stages of Labor | Effacement
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When you are ready to have your baby, you'll go through labor. Labor is the process of giving birth. Signs that you might be going into labor include:
- Contractions that are regular then start to come closer together
- Leaking fluid or bleeding from the vagina
- Low, dull backache
- Abdominal cramps
Call your health care provider if you have any of these signs, even if it is before your due date. Preterm labor can start before 37 completed weeks of pregnancy.
Labor happens in three stages. The first stage begins with contractions. It continues until your cervix has become thinner and dilated (stretched) to about 4 inches wide. The second stage is the active stage, in which you begin to push downward. Crowning is when your baby's scalp comes into view. Shortly afterward, your baby is born. In the third stage, you deliver the placenta. The placenta is the organ that supplied food and oxygen to your baby during pregnancy.
Mothers and babies are monitored closely during labor. Most women are able to have a baby through normal vaginal delivery.
If there are complications, the baby may need to be delivered surgically by a Cesarean section.
NIH: National Institute of Child Health and Human Development
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- Monitoring Baby's Heart Rate during Labor (American Academy of Family Physicians) Also in Spanish
- Water Breaking: Understand This Sign of Labor (Mayo Foundation for Medical Education and Research) Also in Spanish
- Dealing with Pain during Childbirth (Nemours Foundation) Also in Spanish
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- Elective Deliveries Before 39 Weeks: Is It Worth It? (American Academy of Pediatrics)
- Why at Least 39 Weeks Is Best for Your Baby (March of Dimes Birth Defects Foundation)
- Assisted Vaginal Delivery (American College of Obstetricians and Gynecologists)
- Cesarean Section: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
- Episiotomy: When It's Needed, When It's Not (Mayo Foundation for Medical Education and Research) Also in Spanish
- Induction of Labor at 39 Weeks (American College of Obstetricians and Gynecologists)
- Labor Pain (American Society of Anesthesiologists)
- Natural Childbirth (Nemours Foundation) Also in Spanish
- FastStats: Births -- Method of Delivery (National Center for Health Statistics)
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gov: Delivery, Obstetric (National Institutes of Health) - ClinicalTrials.gov: Labor, Obstetric (National Institutes of Health)
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Birth | Definition, Stages, Complications, & Facts
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Summary
Read a brief summary of this topic
birth, also called childbirth or parturition, process of bringing forth a child from the uterus, or womb. The prior development of the child in the uterus is described in the article human embryology. The process and series of changes that take place in a woman’s organs and tissues as a result of the developing fetus are discussed in the article pregnancy.
Initiation of labour
Despite decades of research, the events leading to the initiation of labour in humans remain unclear. It is suspected that biochemical substances produced by the fetus induce labour. In addition, the timing of the production of these substances and their interaction with placental and maternal biochemical factors appear to influence this process.
Among the most studied of these biochemical substances are fetal hormones such as oxytocin and placental inflammatory molecules. Increased placental and maternal production of inflammatory molecules in late pregnancy has been strongly linked to the initiation of labour. Hormonelike substances called prostaglandins, which are produced by the placenta in response to various biochemical signals, can induce inflammation and are present in increased levels during labour. Several factors that increase the production of prostaglandins include oxytocin, which stimulates the force and frequency of uterine contractions, and a fetal lung protein called surfactant protein A (SP-A). Surfactant production in the fetal lung does not begin until the last stages of gestation, when the fetus prepares for air breathing; this transition may act as an important labour switch.
The stages of labour
First stage: dilatation
Early in labour, uterine contractions, or labour pains, occur at intervals of 20 to 30 minutes and last about 40 seconds.
They are then accompanied by slight pain, which usually is felt in the small of the back.
As labour progresses, those contractions become more intense and progressively increase in frequency until, at the end of the first stage, when dilatation is complete, they recur about every three minutes and are quite severe. With each contraction a twofold effect is produced to facilitate the dilatation, or opening, of the cervix. Because the uterus is a muscular organ containing a fluid-filled sac called the amnion (or “bag of waters”) that more or less surrounds the child, contraction of the musculature of its walls should diminish its cavity and compress its contents. Because its contents are quite incompressible, however, they are forced in the direction of least resistance, which is in the direction of the isthmus, or upper opening of the neck of the uterus, and are driven, like a wedge, farther and farther into this opening. In addition to forcing the uterine contents in the direction of the cervix, shortening of the muscle fibres that are attached to the neck of the uterus tends to pull those tissues upward and away from the opening and thus adds to its enlargement.
By this combined action each contraction of the uterus not only forces the amnion and fetus downward against the dilating neck of the uterus but also pulls the resisting walls of the latter upward over the advancing amnion, presenting part of the child.
In spite of this seemingly efficacious mechanism, the duration of the first stage of labour is rather prolonged, especially in women who are in labour for the first time. In such women the average time required for the completion of the stage of dilatation is between 13 and 14 hours, while in women who have previously given birth to children the average is 8 to 9 hours. Not only does a previous labour tend to shorten this stage, but the tendency often increases with succeeding pregnancies, with the result that a woman who has given birth to three or four children may have a first stage of one hour or less in her next labour.
The first stage of labour is notably prolonged in women who become pregnant for the first time after age 35, because the cervix dilates less readily.
A similar delay is to be anticipated in cases in which the cervix is extensively scarred as a result of previous labours, amputation, deep cauterization, or any other surgical procedure on the cervix. Even a woman who has borne several children and whose cervix, accordingly, should dilate readily may have a prolonged first stage if the uterine contractions are weak and infrequent or if the child lies in an inconvenient position for delivery and, as a direct consequence, cannot be forced into the mother’s pelvis.
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On the other hand, the early rupturing of the amnion often increases the strength and frequency of the labour pains and thereby shortens the stage of dilatation; occasionally, premature loss of the amniotic fluid leads to molding of the uterus about the child and thereby delays dilatation by preventing the child’s normal descent into the pelvis. Just as an abnormal position of the child and molding of the uterus may prevent the normal descent of the child, an abnormally large child or an abnormally small pelvis may interfere with the descent of the child and prolong the first stage of labour.
Second stage: expulsion
About the time that the cervix becomes fully dilated, the amnion breaks, and the force of the involuntary uterine contractions may be augmented by voluntary bearing-down efforts of the mother. With each labour pain, she can take a deep breath and then contract her abdominal muscles. The increased intra-abdominal pressure thus produced may equal or exceed the force of the uterine contractions. These bearing-down efforts may double the effectiveness of the uterine contractions.
As the child descends into and passes through the birth canal, the sensation of pain is often increased. This condition is especially true in the terminal phase of the stage of expulsion, when the child’s head distends and dilates the maternal tissues as it is being born.
What is childbirth and how terrible are contractions?
Childbirth is the physiological process of expulsion of the fetal egg from the uterus after the fetus has reached viability. Childbirth occurs at a certain maturity of the uteroplacental system and is regulated by the nervous and endocrine systems.
Labor can be urgent, premature or late.
Term delivery is observed at 37-42 weeks of gestation. Childbirth before the 37th week is usually called premature, and after the 42nd week late. nine0003
Childbirth consists of three periods:
1. The first period (cervical dilation period) it starts from the beginning of regular contractions until the cervix is fully dilated. The degree of cervical dilatation is expressed in centimeters from 0 to 10 and is determined by vaginal examination. As the birth act develops, the intensity and duration of contractions constantly increase, and the duration of the intervals between contractions decreases. In turn, the first stage of labor is divided into: the initial (early or open) phase; middle (active) phase; transitional (deceleration phase). nine0009 2. The second period (exile period) begins from the moment of full dilation of the cervix until the birth of the fetus.
Its average duration is from 30 minutes to 1 hour. After the outflow of amniotic fluid, the contractions weaken for a short time, and then intensify again, which contributes to the advancement of the fetus through the birth canal. The presenting part of the fetus gradually approaches the pelvic floor and exerts pressure on it, as a result of which attempts appear. Over time, the contraction of the muscles of the uterus is joined by the contraction of the muscles of the abdominal press, diaphragm and pelvic floor. As a result, the presenting part of the fetus stretches the genital slit and the head is born, after which the entire torso of the baby appears, at the same time as the posterior amniotic fluid is poured out. nine0009 3. The third stage of childbirth (postpartum period) begins after the birth of the child. The placenta separates and the placenta is born, resulting in about 300 ml of blood being released. As a rule, the placenta separates on its own 5-30 minutes after the birth of the fetus.
This leads to the end of childbirth.
And yet, what worries women in labor the most during childbirth? Naturally - these are contractions - the fear of strong and unbearable pains - is it so? As a rule, the first contractions are not intense and in most cases resemble painful sensations during menstruation. In the future, the strength and intensity of contractions increase. If you put your hand on your stomach, you can feel how the uterus thickens, becomes hard, and then gradually relaxes. At the beginning of labor, the duration of the contractions is from 10 to 15 seconds, and they occur after 10-20 minutes. Then the frequency and strength of contractions continue to increase. In the most active stage, contractions occur after 2-3 minutes, and their duration reaches 60 seconds. Despite the fact that different sections of the uterus begin to contract at different times, the maximum contraction of the vaginal muscles occurs simultaneously. In the normal course of childbirth, with the contraction of the uterus, the necessary conditions are created for the opening of its cervix, as a result of which intrauterine pressure increases, which in turn contributes to the advancement of the fetus through the birth canal.
To understand whether labor activity is regular, it is necessary to watch the frequency and duration of contractions by the clock. It should be borne in mind that after the 20th week of pregnancy, some women experience so-called false contractions, called Braxton-Hicks contractions, which prepare the pregnant woman's body for the upcoming birth. Such contractions are not regular, help soften the cervix and prepare it for childbirth, but do not cause it to open. nine0009 During contractions, a thorough monitoring of the condition of the pregnant woman, the nature of labor, the condition of the uterus and the opening of the cervix is carried out.
Doctors make careful observations by measuring the mother's pulse, examining the fetal heartbeat, and observing other physiological signs. In most modern maternity hospitals, special devices are used to control labor activity, as well as special heart monitors with special sensors. At certain intervals, including during the outflow of amniotic fluid, a vaginal examination is performed to clarify the obstetric situation.
Then, after the full opening of the uterine pharynx, contractions turn into attempts and the second stage of labor begins. nine0003
Childbirth (persons) | it's... What is Rod (human)?
A newborn with an uncircumcised umbilical cord
Childbirth is a natural physiological process that ends the pregnancy and consists in the expulsion of the fetus and placenta from the uterus through the cervical canal and vagina, in this case called the birth canal. The onset of labor is preceded by the appearance of contractions.
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Contents
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2 Promotion (broadcast) Term delivery
Term delivery (urgent) - delivery that took place in the period from the 37th full week to the end of the 42nd week of pregnancy (260-293 days).
Duration of labor
The normal duration of labor may vary slightly. As a rule, the second and subsequent births pass faster than the first. nine0003
- In primiparas, on average, about 9-11 hours, the maximum allowable duration is about 18 hours.
- In multiparous women, on average, about 6-8 hours, the maximum allowable duration is about 13-14 hours.
- If the duration of labor exceeds the maximum allowable duration, then labor is considered prolonged.
- If the birth ended within 4-6 hours in primiparas (2-4 hours in multiparous), then these births are called fast. If the birth ended in less than 4 hours for primiparous (2 hours for multiparous), then these births are called rapid. nine0048
- Any duration of labor that does not meet the standard indicators will be pathological.
Periods of childbirth
The onset of labor is the appearance of regular labor activity (labor pains). There are 3 periods of childbirth: the first period (disclosure), the second (exile), the third (afterbirth).
Cervical dilatation
When contractions begin, the cervix dilates. Also characteristic is the retraction of muscle fibers (displacement of muscle fibers relative to each other). The contraction begins in one of the uterine angles, extends to the body of the uterus, the lower segment. During a normal contraction, the so-called triple downward gradient is observed - the duration, strength and length of the contraction decreases as it spreads from the bottom to the lower segment.
nine0003
The cervix should open from 2-3 cm at the onset of labor to 10-12 cm (depending on the size of the pelvis) or the so-called full opening. Full opening of the cervix (or when the cervix is not defined) is the border between the first and second stages of labor. The opening of the cervix occurs along with its shortening (smoothing).
Most often, at the end of the first stage of childbirth, the fetal bladder opens and amniotic fluid flows out under the influence of many factors acting in childbirth. nine0003
Opening up to 4 cm is slow (0.35-0.5 cm per hour) and is called the latent phase of the first stage of labor. From 4 to 8 cm, the cervix opens quite quickly (1-2 cm per hour) and this phase of the first period is called active. From 8 cm to full opening, the opening speed of the cervix slows down again and this phase is called the deceleration phase.
The duration of the opening period is from 5-8 to 9-12 hours. As a rule, it takes longer in primiparas than in multiparas.
Premature rupture of amniotic fluid
Main article: Premature rupture of amniotic fluid
Premature rupture of amniotic fluid - rupture of membranes and rupture of amniotic fluid before the onset of labor. From the onset of labor to the opening of the cervix, the outflow of amniotic fluid is called early.
Fetal expulsion
From the moment the cervix is fully opened until the fetus is born, this period of labor is called the expulsion period or second period. Obstetricians within this period allocate a straining period - when arbitrary contractions of the diaphragm and muscles of the anterior abdominal wall are connected from the side of the woman. The fetus “makes” translational and rotational movements in the second period (fetal movements are involuntary, due to the expelling forces of the uterus, obstacles from the pelvis - it has the appearance of a transverse ovoid at the entrance, and a longitudinal ovoid at the exit; resistance of the perineum and unequal articulation of the cervical spine and skulls).
The movements are called the biomechanism of childbirth and distinguish between moments that are different depending on the presentation, type and insertion of the fetus. Attempts are desirable to "connect" to contractions when the presenting part completes the internal rotation, and even better when the "lowering" of the presenting part to the pelvic floor. nine0003
In the fetus, as in the object of childbirth, presentation is distinguished (head, pelvic - purely gluteal, mixed and foot variants), view (the ratio of the back of the fetus to the anterior abdominal wall of the mother - anterior or posterior). In the presenting part, identification points are distinguished, by which the physiological or pathological course of childbirth is judged. At the head, this is an sagittal suture (between the parietal bones of the skull) and small and large fontanelles (the junction of three or four bones of the cranial vault). In the case of breech presentation, identification points are distinguished - the intertrochanteric size and the sacrum of the fetus.
Identification points of the presenting part of the fetus are considered in relation to the size, parts and planes of the woman's small pelvis. nine0003
In the second period, the woman receives an allowance to protect the perineum from tearing. This allowance was widely used when it was necessary for a woman to be able to resume work soon after giving birth. Now some elements of the protection of the perineum have not lost their relevance as a factor preventing birth injuries of women. Excessive enthusiasm for the protection of the perineum leads to birth trauma to the fetus. Surgical protection of the perineum is often used - perineo- or episiotomy, as a compromise that prevents, on the one hand, severe trauma to the woman, and on the other, to the fetus. nine0003
Afterbirth
This period starts from the birth of the fetus and ends with the birth of the placenta. The afterbirth consists of the placenta and fetal membranes. In the third period, 2 processes occur: the separation (detachment) of the placenta and the allocation (birth) of the placenta.
It is believed that the third period should normally end in 30 minutes. In order to control the physiological course of the third period, signs of separation of the placenta are used in practice. If there are signs of separation of the placenta, but the placenta is delayed in the uterus, methods are used to isolate the placenta. With the birth of the placenta, the birth is considered completed and the postpartum period begins, lasting (by orders of the Russian Federation and WHO recommendations) 42 days, of which the first 2-4 hours are the early postpartum period. nine0003
Biomechanism of labor
The set of basic movements performed by the fetus during passage through the birth canal is called the biomechanism of labor and includes insertion, advancement, flexion of the head, internal rotation of the head, extension of the head, external rotation of the head and expulsion of the fetus.
For didactic purposes, the various moments of the biomechanism of childbirth are considered as if they occur separately, but in fact they are all closely related and occur simultaneously.
Indeed, flexion, extension and rotation of the head are impossible if at the same time the fetus does not move down the birth canal. In addition, the contractile activity of the uterus affects the articulation of the fetus, especially after the head has descended into the cavity of the small pelvis - the fetus straightens, and the limbs are pressed closer to the body. Thus, the fetus from an ovoid shape becomes cylindrical and in all its parts (head, shoulders, pelvic end) is approximately the same size. nine0003
Insertion
Overcoming the large segment of the head (a circle corresponding to the biparietal size - the maximum transverse size of the head in the occipital presentation) of the entrance to the small pelvis is called its insertion. Insertion can occur in the last weeks of pregnancy or after the onset of labor. Before insertion, the head is free, mobile over the entrance to the small pelvis and ballots during palpation. The head of a full-term baby is almost never inserted so that the sagittal suture is set in the direct size of the entrance to the small pelvis; usually it is located either in transverse or in one of the oblique dimensions.
nine0003
Asynclitism
The sagittal suture of the fetal head tends to enter the small pelvis through the transverse dimension of the entrance plane, however, in practice, remaining parallel to this dimension, it may not lie strictly between the promontory and the pubic symphysis, but move either back, towards the promontory, or forward, to the symphysis. Such lateral tilts of the head with a shift of the swept seam back and forth are called asynclitism.
Slight asynclitism is common for normal births, but severe asynclitism is dangerous due to the discrepancy between the size of the fetal head and the normal pelvis of the woman in labor (clinically narrow pelvis). nine0003
Advancement (broadcast)
Translational movement of the fetus through the birth canal is the first condition for normal delivery. In nulliparous women, the insertion of the head is possible even before childbirth, however, further omission of the fetus will not occur until the second stage of labor (exile period) begins.
In multiparous, the advancement of the fetus coincides with the insertion. There are several forces that ensure the movement of the fetus through the birth canal: 1) pressure of amniotic fluid, 2) direct pressure of the fundus of the uterus on the pelvic end of the fetus during contractions, 3) contraction of the striated abdominal muscles during attempts, and 4) extension of the body of the fetus. nine0003
Flexion of the glans
When the glans encounters an obstacle in its path, whether it be an undistended cervix, pelvic wall or pelvic floor muscles, the glans flexes. In this case, the chin is even more tightly pressed against the breast of the fetus, and instead of a straight size, the head turns into the birth canal with a small oblique one.
Internal rotation of the head
Internal rotation is the rotation of the head of the fetus so that the occiput gradually turns either forward, towards the pubic symphysis, or, more rarely, backwards, towards the anterior surface of the sacrum.
Internal rotation is required for full-term delivery; it can fall out of the general biomechanism of childbirth only when the fetus is unusually small. Internal rotation is always combined with the translational movement of the fetus, but does not occur before the lower pole of the head reaches the iliac spines, that is, after insertion. nine0003
Extension of the head
When the head reaches the plane of exit from the small pelvis, the birth canal turns upward, and for further advancement, it rests with the suboccipital fossa (point of fixation) on the lower edge of the pubic symphysis and rotates around this point; thus, the extension of the head occurs. Extension is provided by the simultaneous action on the fetus of the forces developed by the uterus and the resistance of the pelvic floor muscles.
External rotation of the head
The born head, trying to return to its natural position, turns in the opposite direction: if before the internal rotation the back of the head was directed to the left, then now it turns to the left, to the left ischial tuberosity; if it was directed to the right, then it turns to the right, to the right ischial tuberosity.
Further rotation of the head occurs due to the internal rotation of the shoulders, which are set by the interacromial size in the direct size of the exit from the small pelvis. In this case, one (anterior) shoulder extends beyond the pubic symphysis, and the second (posterior) shoulder lies on the anterior surface of the sacrum. The internal rotation of the shoulders is carried out under the action of the same forces that cause the internal rotation of the head. nine0003
Expulsion of the fetus
Almost immediately after the external rotation of the head under the womb, the anterior shoulder is shown, and soon the posterior shoulder is also born. This is followed by rapid expulsion of the fetal body.
Terminology
Woman in labor and childbirth
- Woman in labor is a medical term in obstetrics and gynecology; a pregnant woman who is already in labor (giving birth).
- Postpartum - this term refers to a woman who has already (just, recently) given birth.
