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Childbirth

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Childbirth (also called labo(u)r, birth, partus or parturition) is the culmination of a human pregnancy with the emergence of a newborn infant from its mother's uterus.

A woman is considered to be in labour when she begins experiencing regular, strong uterine contractions, accompanied by changes of her cervix — primarily effacement and dilation. While childbirth is widely experienced as painful, some women do report painless labours. When the baby is born its birth weight is determined.

The normal birth

File:Normal Childbirth.jpg
Newborn with umbilical cord still attached after a Water birth

First stage: contractions

A typical human childbirth will begin with the onset of contractions of the uterus. The frequency and duration of these contractions varies with the individual. The onset of labour may be sudden or gradual, and is defined as regular uterine activity in the presence of cervical dilatation.

During a contraction the long muscles of the uterus contract, starting at the top of the uterus and working their way down to the bottom. At the end of the contraction, the muscles relax to a state shorter than at the beginning of the contraction. This draws the cervix up over the baby's head. Each contraction dilates the cervix until it becomes completely dilated, often referred to as 10+ cm (4") in diameter.

A gradual onset with slow cervical change towards 3 cm (just over 1 inch) dilation is referred to as the "latent phase". A woman is said to be in "active labour" when contractions have become regular in frequency (3-4 in 10 minutes) and about 60 seconds in duration. The now powerful contractions are accompanied by cervical effacement and dilation greater than 3 cm. The labour may begin with a rupture of the amniotic sac, the paired amnion and chorion ("breaking of the water"). The contractions will accelerate in frequency and strengthen. In the "transition phase" from 8 cm–10 cm (3 or 4 inches) of dilation, the contractions often come every two minutes are typically lasting 70–90 seconds. Transition is often regarded as the most challenging and intense for the mother. It is also the shortest phase.

During this stage, the expectant mother typically goes through several emotional phases. At first, the mother may be excited and nervous. Then, as the contractions become stronger, demanding more energy from the mother, mothers generally become more serious and focused. However, as the cervix finishes its dilation, some mothers experience confusion or bouts of self-doubt or giving up.

The duration of labour varies widely, but averages some 13 hours for women giving birth to their first child ("primiparae") and 8 hours for women who have already given birth.

If there is a significant medical risk to continuing the pregnancy, induction may be necessary. As this carries some risk, it is only done if the child or the mother are in danger from prolonged pregnancy. Forty-two weeks gestation without spontaneous labour is often said to be an indication for induction although evidence does not show improved outcomes when labour is induced for post-term pregnancies. Inducing labour increases the risk of cesarean section and uterine rupture in mothers that have had a previous cesarean section.

Second stage

In the second stage of labour, the baby is expelled from the womb through the vagina by both the uterine contractions and by the additional maternal efforts of "bearing down," which many women describe as similar in sensation to straining to expel a large bowel movement. The imminence of this stage can be evaluated by the Malinas score.

The baby is most commonly born head-first. In some cases the baby is "breech" meaning either the feet or buttocks are descending first. Babies in the breech position can be delivered vaginally by a midwife, though in some areas finding an experienced willing attendant can be difficult.

There are several types of breech presentations, but the most common is where the baby's buttocks are delivered first and the legs are folded onto the baby's body with the knees bent and feet near the buttocks (full or breech). Others include frank breech, much like full breech but the babies legs are extended toward his ears, and footling or incomplete breech, in which one or both legs are extended and the foot or feet are the presenting part. Another rare presentation is a transverse lie. This is where the baby is sideways in the womb and a hand or elbow has entered the birth canal first. While babies who present transverse will often move to a different position, this is not always the case and a cesarean birth then becomes necessary.

A newborn baby with umbilical cord ready to be clamped

The length of the second stage varies and is affected by whether a woman has given birth before, the position she is in and mobility. The length of the second stage should be guided by the condition of the fetus and health of the mother. Problems may be encountered at this stage due to reasons such as maternal exhaustion, the front of the baby's head facing forwards instead of backwards (posterior baby), or extremely rarely, because the baby's head does not fit properly into the mother's pelvis (Cephalo-Pelvic Disproportion (CPD)). True CPD is typically seen in women with rickets and bone deforming illnesses or injuries, as well as arbitrary time limits placed on second stage by caregivers or medical facilities.

Immediately after birth, the child undergoes extensive physiological modifications as it acclimatizes to independent breathing. Several cardiovascular structures start regressing soon after birth, such as the ductus arteriosus and the foramen ovale. In some cultures, the father cuts the umbilical cord and the infant is given a lukewarm bath to remove blood and some of the vernix on its skin before being handed back to its parents.

The practice of leaving the umbilical cord to detach naturally is known as a Lotus Birth.

The medical condition of the child is assessed with the Apgar score, based on five parameters: heart rate, respiration, muscle tone, skin color, and response to stimuli. Apgar scores are typically assessed at both 1 and 5 minutes after birth.

Third stage: placenta

Breastfeeding during and after the third stage

In this stage, the uterus expels the placenta (afterbirth). Breastfeeding the baby will help to cause this. The mother normally loses less than 500 mL of blood. Blood loss will be greater if the umbilical cord is used to tug on the placenta. It is essential that the placenta be examined to ensure that it was expelled whole. Remaining parts can cause postpartum bleeding or infection.

After the birth

Medical professionals typically recommend breastfeeding of the first milk, colostrum, to reduce postpartum bleeding/hemorrhage in the mother, and to pass immunities and other benefits to the baby.

Parents usually assign the infant its given names soon after birth.

Often people visit and bring a gift for the baby.

Many cultures feature initiation rites for newborns, such as naming ceremonies, baptism, and others.

Mothers are often allowed a babymoon period where they are relieved of their normal duties to recover from childbirth and establish breastfeeding with their babies. Length of this period varies. In China this is 30 days and is referred to as "doing the month" (see Postpartum period).

A birth story may be written, detailing the events of the birth. The story may be posted to a blog or web forum.

Variations

When the amniotic sac has not ruptured during labour or pushing, the infant can be born with the membranes intact. This is referred to as "being born in the caul." The caul is harmless and its membranes are easily broken and wiped away by the doctor or midwife assisting with the childbirth. In medieval times, and in some cultures still today, a caul was seen as a sign of good fortune for the baby, in some cultures was seen as protection against drowning. The caul was often impressed onto paper and stored away as an heirloom for the child. With the advent of modern interventive obstetrics, premature artificial rupture of the membranes has become common, so babies are rarely born in the caul.

Pain

The amounts of pain experienced by women during childbirth varies. For some women, the perceived pain is intense and agonizing; for other women there is little to no perceived pain. Many factors affect pain perception; cultural ideas of childbirth, fear, number of previous births, fetal presentation, birthing position, support given during labor, beta-endorphin levels, and a woman's natural pain threshold. Uterine contractions are always intense during childbirth, but a woman may or may not experience them as pain.

Some women sleep through much of the labor. Rarely, mothers experience very pleasurable sensations and muscular contractions which they believe to be orgasms.

Non-medical pain control

Many women believe that reliance on analgesic medication is unnatural, or worry that it may harm the child, but are still very concerned about labour pain. To alleviate pain, they may undergo psychological preparation, education, massage, hypnosis, water therapy in a tub or shower. Most women also find helpful the emotional support and comfort measures by a husband, partner, or a trained professional doula. Birthing in a squatting or crawling position is often favored by women. These methods present no risk to the mother or baby, and many find them effective.

The human body also has its own method of pain control for labour and childbirth in the form of beta-endorphins. As a naturally occurring opiate, beta-endorphin has properties similar to pethidine, morphine, and heroin, and has been shown to work on the same receptors of the brain. [1] Like oxytocin, beta-endorphin is secreted from the pituitary gland, and high levels are present during sex, pregnancy, birth, and breastfeeding. This hormone can induce feelings of pleasure and euphoria during childbirth.[2]

Water births are being increasingly chosen by many women as an option for pain relief during labour and childbirth, and waterbirth has been proven in many trials to be not only a safe option for mother and baby, but in many cases show a reduction in the need for further analgesia, and a higher rate of birth 'without injuries' [1][2][3][4] Many hospitals and birthing centres now offer women the option of waterbirth, either via custom-made 'birthing pools' or large bath tubs, and have policies to safeguard their use.

Medical pain control

In Europe, doctors commonly prescribe inhaled nitrous oxide gas for pain control; in the UK, midwives may use this gas without a doctor's prescription. Pethidine (with or without promethazine) may be used early in labour, as well as other opioids; if given too close to birth, they may cause respiratory depression in the infant.

Popular medical pain control in hospitals include regional anesthetics (epidural blocks, or spinal anaesthesia); these anesthetics are often used for pain control, and are a necessity for Cesarean surgery, unless the patient undergoes general anesthetic. Doctors favor the epidural block because medication does not enter the mother's circulatory system, thus it does not cross the placenta and enter the bloodstream of the fetus. Studies however suggest that epidural use can lengthen the labour, and may compromise breastfeeding success [5][6].

Different measures for pain control have varying degrees of success and side effects to mother and baby. Administration must be carefully timed. For example, an epidural block given too early in labour can stop or slow labour, and given too late in labour can hinder maternal efforts to push out the baby. These risks should be balanced against the fact that childbirth can be extremely painful, and anesthetics are an effective and generally safe pain treatment.

Complications and risks of birth

Problems that occur during childbirth are called complications. They can affect the mother or the baby. Sometimes they cause injury or even death. Doctors and midwives are trained to deal with these problems should they occur.

Infant deaths (neonatal deaths from birth to 28 days, or perinatal deaths if including fetal deaths at 28 weeks gestation and later) are around 1% in modernized countries. The risk of maternal death during childbirth in developed nations is comparatively low; only about 1 in 1800 mothers die in childbirth (only 1 in 3700 in North America). In the Third World, it is a much riskier proposition: neonatal deaths rates in Sub-Saharan Africa and South Asia are more than 3.7%[3], and on average 1 in 48 women die during childbirth.[4] The "natural" mortality rate of childbirth—where nothing is done to avert maternal death—has been estimated as being between 1,000 and 1,500 deaths per 100,000 births.[5] (See main article: neonatal death, maternal death)

The most important factors affecting mortality in childbirth are adequate nutrition and access to quality medical care ("access" is affected both by the cost of available care, and distance from health services). "Medical care" in this context does not refer specifically to treatment in hospitals, but simply the presence of an attendant with midwifery skills. A 1983-1989 study by the Texas Department of Health revealed that the infant death rate was 0.57% for doctor-attended births, and 0.19% for births attended by non-nurse midwives. Conversely, some studies demonstrate a higher perinatal mortality rate with assisted home births.[6] It is generally accepted that in developed countries, properly assisted home births carry no greater risks than hospital birth for low-risk pregnancies. Around 80% of pregnancies are low-risk. Factors that may make a birth high risk include prematurity, high blood pressure, diabetes and previous cesarean section.

One of the most dangerous risks to the fetus is that of premature birth, and its associated low neonatal weight. The more premature (or underweight) a baby is, the greater the risks for neonatal death and for pulmonary, respiratory, neurological or other sequelae. About 12% of all infants born in the United States are born prematurely. In the past 25 years, medical technology has greatly improved the chances of survival of premature infants in industrialized nations. In the 1950s and 1960s, approximately half of all low birth weight babies in the US died. Today, more than 90% survive. The first hours of life for "premies" are critical, especially the very first hour of life. Rapid access to a Neonatal Intensive Care Unit is of paramount importance.

Some of the possible complications are:

  • Heavy bleeding during or after childbirth, which is the most common cause of mortality in new mothers, in both developed and undeveloped nations.[3] Heavy blood loss leads to hypovolemic shock, insufficient perfusion of vital organs and death if not rapidly treated by stemming the blood loss (medically with ergometrine and pitocin or surgically) and blood transfusion. Hypopituitarism after obstetric hypovolemic shock is termed Sheehan's syndrome.
  • Non-progression of labour (longterm contractions without adequate cervical dilation) is generally treated with intravenous synthetic oxytocin preparations. If this is ineffective, Caesarean section may be necessary. Changes in maternal position is effective in many cases.
  • Fetal distress is the development of signs of distress by the child. These may include rising or decreasing heartbeat (monitored on cardiotocography/CTG), shedding of meconium in the amniotic fluid, and other signs.
  • Non-progression of expulsion (the head or presenting parts are not delivered despite adequate contractions): this can require interventions such as vacuum extraction, forceps extraction or Caesarean section.
  • In the past, a large proportion of women died from infection puerperal fever, but since the introduction of basic hygiene during parturition by Ignaz Semmelweis, this number has fallen precipitously.
  • Lacerations can be painful. An episiotomy is occasionally necessary to avoid tears involving the anal sphincter, but its routine use—once normal—has now been shown to be harmful.

Professions associated with childbirth

Midwives are experts in normal birth. Midwives believe that childbirth is a normal process that is best accomplished with as little interference as possible. Midwives are trained to assist at births, either through direct-entry or nurse-midwifery programs. Lay midwives typically train in apprenticeship programs with experienced midwives.

Obstetricians are experts in dealing with abnormal births and pathological labour conditions, though they sometimes attend normal births as a precautionary measure. Obstetricians in most countries are trained as surgeons, so they can undertake surgical procedures relating to childbirth. Such procedures include caesarean sections, episiotomies, or emergency hysterectomies. Obstetricians' tendency to intervene surgically to overcome complications has led to criticism that they perform surgery too readily. In the United States, obstetric malpractice settlements are typically very large, so obstetricians argue that they are forced to intervene aggressively to limit their liability.

In the United States, a doctor who specializes in caring for women with pregnancy complications is often referred to as a maternal-fetal medicine sub-specialist.

Obstetric nurses assist doctors, mothers, and babies prior to, during, and after the birth process. Some midwives are also obstetric nurses. Obstetric nurses hold various certifications and typically undergo additional obstetric training in addition to standard nursing training

Social aspects

In most cultures, childbirth is considered to be the beginning of a person's life, and a person's age is defined relative to it.

Many families view the placenta as a special part of birth, since it has been the child's life support for so many months. Many parents like to see and touch this mysterious organ. In some cultures, parents plant a tree along with the placenta on the child's first birthday. The placenta may be eaten by the newborn's family, ceremonially or otherwise.

In November 2004 Aleta St. James, a 56 year old single mother gave birth to twins conceived through in vitro fertilization. In 2005, a 67 year old Romanian woman gave birth by cesarean to one surviving twin.

In some legal jurisdictions, the place of childbirth decides the nationality of a child (under the doctrine of Jus soli)

Psychological aspects

Childbirth can be a stressful event. As with any stressful event, strong emotions can be brought to the surface. Medicating the mother against her labor pain is a widespread practice in hospitals. Intravenously-administered drugs — although not, as discussed above, epidurals — may reach the infant's bloodstream through the umbilical cord, with uncertain effects. Some women report symptoms compatible with post-traumatic stress disorder (PTSD) after birth. Between 70 and 80% of mothers in the United States report some feelings of sadness or "baby blues" after childbirth. Postpartum depression may develop in some women; about 10% of mothers in the United States are diagnosed with PPD.

Preventative group therapy has proven effective as a prophylactic treatment for postpartum depression.[7]

Childbirth is also stressful for the infant. Stresses associated with breech birth, such as asphyxiation, may affect the infant's brain.

It is not known how the birth experience affects the development of personality in the infant. It was once thought that newborns do not have the capacity to feel pain or fear, and now some parents are choosing alternative birth settings (other than the hospital) in an attempt to create a more comfortable environment not only for the newborn, but the birthing mother and other family members.

Partner and other support

There is increasing evidence to show that the participation of the woman's partner in the birth leads to better birth and also post-birth outcomes, as long as the partner does not exhibit excessive anxiety. Research also shows that when a labouring woman was supported by a doula during labour, she had less need for chemical pain relief, the likelihood of caesarean section was reduced, use of forceps and other instrumental deliveries were reduced and there was a reduction in the length of labour and the baby had a higher Apgar score (Dellman 2004), (Vernon 2006).

Well known authors on childbirth

References

  • Dellman, Thomas, The Best Moment of my Life - a literature review of fathers experience of childbirth, Australian Midwifery Journal, Australian College of Midwives, 2004 17(3) 20-26
  • David Vernon, Men at Birth, Australian College of Midwives, 2006
  1. ^ H H Loh, L F Tseng, E Wei, and C H Li Beta-endorphin is a potent analgesic agent. Proc Natl Acad Sci U S A. 1976 August; 73(8): 2895–2898.
  2. ^ M. Brinsmead et al., "Peripartum Concentrations of Beta Endorphin and Cortisol and Maternal Mood States," Australian and New Zealand Journal of Obstetrics and Gynaecology 25 (1985): 194-197
  3. ^ a b World Health Organization 2005 World Health Report, Chapter 4: Risking Death To Give Life, The Greatest Risks to Life are in its Beginning
  4. ^ Safer Motherhood Fact Sheet: Maternal Mortality
  5. ^ Van Lerberghe W, De Brouwere V. Of blind alleys and things that have worked: history’s lessons on reducing maternal mortality. In: De Brouwere V, Van Lerberghe W, eds. Safe motherhood strategies: a review of the evidence. Antwerp, ITG Press, 2001 (Studies in Health Services Organisation and Policy, 17:7–33).
  6. ^ "Perinatal death associated with planned home birth in Australia: population based study". BMJ. 317(7155):384-8. Retrieved May 28. {{cite web}}: Check date values in: |accessdate= (help); Unknown parameter |accessyear= ignored (|access-date= suggested) (help)
  7. ^ Zlotnick C, Johnson SL, Miller IW, Pearlstein T, Howard M. Postpartum depression in women receiving public assistance: pilot study of an interpersonal-therapy-oriented group intervention, Am J Psychiatry. 2001 Apr;158(4):638-40. [PMID 11282702]
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