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Childbirth (also called labour, birth, or parturition) is the culmination of pregnancy, the emergence of a child from its mother's uterus. It is considered by many to be the beginning of a person's life, and hence the opposite of death. Age is defined relative to this event in most cultures. A woman is considered to be in labour the moment she develops regular painful uterine contractions, which are accompanied by changes of her cervix, these primarily being effacement and dilation.
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The medical science of childbirth is obstetrics and a doctor who specializes in attending births is an obstetrician. Obstetricians are surgeons, who are trained to see childbirth as potentially pathological and in need of routine interventions. Midwives see childbirth as a normal event for most women, one which is best handled by as few interventions as possible. Midwives are trained to assist at births either through direct-entry or nurse-midwifery programs.
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. A gradual onset with slow cervical change towards 3 cm dilation is referred to as the "latent phase". A woman is said to be in "established labour" when painful contractions have become regular in frequency (3-4 in 10 minutes) and less than 60 seconds in duration. The now powerful contractions are accompanied by cervical effacement and dilation greater than 3cm. The labour may begin with a rupture of the amniotic sac, the paired amnion and chorion ("breaking of the water"). The contractions will accelerate until they happen every two minutes although this is not always the case. The length of the contractions will also lengthen until at the end of the first stage they are typically lasting 70 - 90 seconds.
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 reaches 10+ centimetres (4") in width.
During this stage, the expectant mother typically goes through several emotional phases. At first, the mother will be excited. Then, as the contractions become stronger, demanding more energy from the mother, the mother will become very serious and focused. However, as the cervix finishes its dilation, most mothers experience confusion or bouts of self-doubt. The latter is a reliable indication that the First Stage is nearly over.
The duration of labour varies wildly, 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 contractions do not commence spontaneously, induction (by prostaglandin gel or pitocin) may be necessary. As this carries some risk, it is only done if the child or the mother are in danger from prolonged pregnancy. 42 weeks gestation without spontaneous labor is often an indication for induction.
In the second stage of labour, the baby is expelled from the womb through the birth canal by both the uterine contractions and by powerful abdominal contractions ("bearing down"). The baby is most commonly born head-first. In some cases the baby is breech meaning either the feet or buttocks are descending first. With properly trained staff and the right circumstances, even babies in the "breech" position can be delivered vaginally.
There are several types of breech presentations 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 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. A vaginal birth should not be attempted, although in rare cases the arm can be pushed back up and the baby can be coaxed into the proper position.
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 tage should be guided by the condition of the foetus and health of the mother. Problems may be encountered at this stage due to reasons such as inadequate maternal effort or maternal exhaustion, the front of the baby's head is facing forwards instead of backwards, or more rarely, because the baby's head does not fit properly into the mother's pelvis (cephalo-pelvic disproportion).
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.
The medical condition of the child is assessed with the Apgar score, based on five parameters. A "good start" refers to higher scores, while a child doing poorly with have low scores that do not improve rapidly over time.
In this stage, the uterus expels the placenta (afterbirth) and the mother normally loses less than 500ml of blood. It is essential that the whole placenta is expelled, so the midwife will examine the placenta to ensure that it is intact. Remaining parts can cause postnatal haemorrhage or infection.
Usually soon after birth the parents assign the infant its given names. They may have two sets of names in mind, one for if it is a boy, and one for if it is a girl.
Often people visit and bring a gift for the baby.
Many cultures feature initiation rites for newborns, such as circumcision or baptism, amongst others.
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 easily wiped away by the doctor or person assisting with the childbirth. In medieval times, a caul was seen as a sign of good fortune for the baby, in some cultures was seen as protection against drowning, and 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 and it is rare for infants to be born in the caul in Western births.
Due to the relatively large size of the human skull and the shape of the human pelvis forced by the erect posture, childbirth is more difficult and painful for human mothers than other mammals. Many methods are available to reduce the pain of labour, including psychological preparation, emotional support, epidural analgesia, spinal anaesthesia, nitrous oxide, opioids, and natural childbirth methods such as the Lamaze technique or Bradley Method. Each method has its own advantages and disadvantages.
Complications occasionally arise during childbirth; these generally require management by an obstetrician.
Non-progression of labor (longterm contractions without adequate cervical dilation) is generally treated with intravenous synthetic oxytocin preparations. If this is ineffective, Caesarean section may be necessary.
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 (up to 20%) died during or shortly after childbirth, often from puerperal fever, but since the introduction of basic hygiene during parturition by Ignaz Semmelweis, this number has fallen precipitously.
Unanticipated heavy bleeding during or after childbirth is potentially lethal in places without immediate access to high level emergency care. 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.
In modern times, participation of the father during childbirth is now the norm. However, before the 1960s, in most cultures the father was forbidden to enter childbirth area, as were other men with the exception of the doctor.
An exception to this rule were Poleshuks from Polesie. In old times in this culture the wife gave birth sitting on her husband's knees.
The recent social development of requiring signed consent, permitting fathers into the birth area, and leaving the mother with less impairment from drugs and physical restraint, has led to a considerable increase in parental control over all aspects the birth process. In recent years, many believe all of these social changes have allowed reductions in circumcision rates, along with drops in other interventions, such as episiotomy.
Often times 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, there is a custom to dig a hole and plant a tree along with the placenta on the child's first birthday -- in some populations, it is ceremonially eaten by the newborn's family.
The eldest American woman known to give birth was Arceli Keh, aged 63. In November 2004 Aleta St. James, a 56 year old single mother gave birth to twins conceived through in vitro fertilization; days later, it was announced that Frances Harris, a 59 year old great-grandmother who had had a tubal ligation thirty years ago had become pregnant with twins due in December.
In some legal jurisdictions, the place of childbirth decides the nationality of a child (under the doctrine of Jus soli)
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