Labor (childbirth)

Childbirth, labour, delivery, birth, partus, or parturition is the culmination of a pregnancy period with the expulsion of one or more newborn infants from a woman's uterus. The process of normal childbirth is categorized in three stages of labour: the shortening and dilation of the cervix, descent and birth of the infant, and birth of the placenta.

In many cases and with increasing frequency, childbirth is achieved through induction of labor or caesarean section, which is the removal of the neonate through a surgical incision in the abdomen, rather than through vaginal birth. Childbirth by C-Sections increased 50% in the U.S. from 1996 to 2006, and comprise nearly 32% of births in the U.S. and Canada. With respect to induced labor, more than 22% of women undergo induction of labour in the United States. Medical professional policy makers find that prior to 39 weeks induced births and elective cesarean can be harmful to the neonate as well as harmful or without benefit to the mother, and have endorsed guidelines for non-medically indicated induced births and elective cesarean before 39 weeks.

Signs and symptoms
Pain levels reported by labouring women vary widely. They appear to be influenced by fear and anxiety levels, experience with prior childbirth, cultural ideas of childbirth and pain, mobility during labour and the support given during labour. One small study found that middle-eastern women, especially those with a low educational background, had more painful experiences during childbirth.

Pain is only one factor of many influencing women's experience with the process of childbirth. A systematic review of 137 studies found that personal expectations, the amount of support from caregivers, quality of the caregiver-patient relationship, and involvement in decisionmaking are more important in women's overall satisfaction with the experience of childbirth than are other factors such as age, socioeconomic status, ethnicity, preparation, physical environment, pain, immobility, or medical interventions.

Descriptions
Pain in contractions has been described as feeling similar to very strong menstrual cramps. Women are often encouraged to refrain from screaming, but moaning and grunting may be encouraged to help lessen pain. Crowning may be experienced as an intense stretching and burning. Even women who show little reaction to labor pains, in comparison to other women, show a substantially severe reaction to crowning.

Psychological
Childbirth can be an intense event and strong emotions, both positive and negative, can be brought to the surface. Abnormal and persistent fear of childbirth is known as tokophobia.

During the later stages of gestation there is an increase in abundance of oxytocin, a hormone that is known to evoke feelings of contentment, reductions in anxiety, and feelings of calmness and security around the mate. Oxytocin is further released during labor when the fetus stimulates the cervix and vagina, and it is believed that it plays a major role in the bonding of a mother to her infant and in the establishment of maternal behavior. The act of nursing a child also causes a release of oxytocin.

Between 70% and 80% of mothers in the United States report some feelings of sadness or "baby blues" after childbirth. The symptoms normally occur for a few minutes up to few hours each day and they should lessen and disappear within two weeks after delivery. Postpartum depression may develop in some women; about 10% of mothers in the United States are diagnosed with this condition. Preventive group therapy has proven effective as a prophylactic treatment for postpartum depression.

Vaginal birth
Because humans are bipedal with an erect stance and have, in relation to the size of the pelvis, the biggest head of any mammalian species, human fetuses and human female pelvises are adapted to make birth possible.

The erect posture causes the weight of the abdominal contents to thrust on the pelvic floor, a complex structure which must not only support this weight but allow three channels to pass through it: the urethra, the vagina and the rectum. The infant's head and shoulders must go through a specific sequence of maneuvers in order to pass through the ring of the mother's pelvis.

Six phases of a typical vertex (head-first presentation) delivery:
 * 1) Engagement of the fetal head in the transverse position. The baby's head is facing across the pelvis at one or other of the mother's hips.
 * 2) Descent and flexion of the fetal head.
 * 3) Internal rotation. The fetal head rotates 90 degrees to the occipito-anterior position so that the baby's face is towards the mother's rectum.
 * 4) Delivery by extension. The fetal head passes out of the birth canal. Its head is tilted forwards so that the crown of its head leads the way through the vagina.
 * 5) Restitution. The fetal head turns through 45 degrees to restore its normal relationship with the shoulders, which are still at an angle.
 * 6) External rotation. The shoulders repeat the corkscrew movements of the head, which can be seen in the final movements of the fetal head.

Station refers to the relationship of the fetal presenting part to the level of the ischial spines. When the presenting part is at the ischial spines the station is 0 (synonymous with engagement). If the presenting fetal part is above the spines, the distance is measured and described as minus stations, which range from -1 to -4 cm. If the presenting part is below the ischial spines, the distance is stated as plus stations ( +1 to +4 cm). At +3 and +4 the presenting part is at the perineum and can be seen.

The fetal head may temporarily change shape substantially (becoming more elongated) as it moves through the birth canal. This change in the shape of the fetal head is called molding and is much more prominent in women having their first vaginal delivery.

First Stage: Latent Phase
The first stage of labor is divided into latent and active phases.

The latent phase of labour is also called prodromal labour or pre-labour. It is a subclassification of the first stage".

The latent phase is generally defined as beginning at the point at which the woman perceives regular uterine contractions. In contrast, Braxton Hicks contractions, which are contractions that may start around 26 weeks gestation and are sometimes called "false labour", should be infrequent, irregular, and involve only mild cramping.

Cervical effacement, which is the thinning and stretching of the cervix, and cervical dilation occur during the closing weeks of pregnancy and is usually complete or near complete, by the end of the latent phase. The degree of cervical effacement may be felt during a vaginal examination. A 'long' cervix implies that effacement has not yet occurred. Latent phase ends with the onset of active first stage, and this transition is defined retrospectively.

First Stage: Active Phase
The active stage of labour (or "active phase of first stage" if previous phase is termed "latent phase of first stage") is defined as the point at which the rate of cervical change accelerates. Health care providers may assess a laboring mother's progress in labor by performing a cervical exam to evaluate the cervical dilation, effacement, and station. These factors form the Bishop Score. The Bishop Score can also used as a means to predict the success of an induction of labor.

During effacement, the cervix becomes incorporated into the lower segment of the uterus. During a contraction, uterine muscles contract causing shortening of the upper segment and drawing upwards of the lower segment, in a gradual expulsive motion. The presenting fetal part then is permitted to descend. Full dilation is reached when the cervix has widened enough to allow passage of the baby's head, around 10 cm dilation for a term baby.

The duration of labour varies widely, but active phase averages some 8 hours for women giving birth to their first child ("primiparae") and shorter for women who have already given birth ("multiparae"). Active phase prolongation is defined as in a primigravid woman as the failure of the cervix to dilate at a rate of 1.2 cm/hr over a period of at least two hours. This definition is based on Friedman's Curve, which plots the typical rate of cervical dilation and fetal descent during active labour. Some practitioners may diagnose "Failure to Progress", and consequently, propose interventions to optimize chances for healthy outcome.

Second stage: fetal expulsion
This stage begins when the cervix is fully dilated, and ends when the baby is born. As pressure on the cervix increases, women may have the sensation of pelvic pressure and an urge to begin pushing. At the beginning of the normal second stage, the head is fully engaged in the pelvis; the widest diameter of the head has passed below the level of the pelvic inlet. The fetal head then continues descent into the pelvis, below the pubic arch and out through the vaginal introitus (opening). This is assisted by the additional maternal efforts of "bearing down" or pushing. The appearance of the fetal head at the vaginal orifice is termed the "crowning". At this point, the woman will feel an intense burning or stinging sensation.

Complete expulsion of the baby signals the successful completion of the second stage of labour.



The second stage of birth will vary by factors including parity, fetal size, anesthesia, the presence of infection. Longer labours are associated with declining rates of spontaneous vaginal delivery and increasing rates of infection, perineal laceration, obstetric hemorrhage, as well as need for intensive care of the neonate.

Third stage: delivery of the placenta
The period from just after the fetus is expelled until just after the placenta is expelled is called the third stage of labour.

The umbilical cord is routinely clamped and cut in this stage. General hospital-based obstetric practice introduces artificial clamping as early as 1 minute after the birth of the child. In birthing centers, this may be delayed by 5 minutes or more, or omitted entirely. Delayed clamping of the cord decreases the risk of anemia but may increase risk of jaundice. Clamping is followed by cutting of the cord, which is painless due to the absence of nerves.

Placental expulsion begins as a physiological separation from the wall of the uterus. The period from just after the fetus is expelled until just after the placenta is expelled is called the third stage of labour. The average time from delivery of the baby until complete expulsion of the placenta is estimated to be 10–12 minutes dependent on whether active or expectant management is employed In as many as 3% of all vaginal deliveries, the duration of the third stage is longer than 30 minutes and raises concern for retained placenta.

Placental expulsion can be managed actively or it can be managed expectantly, allowing the placenta to be expelled without medical assistance. Active management is described as the administration of a uterotonic drug within one minute of fetal delivery, controlled traction of the umbilical cord and fundal massage after delivery of the placenta, followed by performance of uterine massage every 15 minutes for two hours. In a joint statement, World Health Organization, the International Federation of Gynaecology and Obstetrics and the International Confederation of Midwives recommend active management of the third stage of labour in all vaginal deliveries to help to prevent postpartum hemorrhage.

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 "delivery en caul.

Fourth stage
The "fourth stage of labour" is the period beginning immediately after the birth of a child and extending for about six weeks. Another term would be postpartum period, as it refers to the mother (whereas postnatal refers to the infant). Less frequently used is puerperium.

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

Mothers are often allowed a period where they are relieved of their normal duties to recover from childbirth. The length of this period varies. In many countries, taking time off from work to care for a newborn is called "maternity leave" or "parental leave" and can vary from a few days to several months.

Management
Eating or drinking during labour is an area of ongoing debate. While some have argued that eating in labour has no harmful effects on outcomes, others continue to have concern regarding the increased possibility of an aspiration event (choking on recently eaten foods) in the event of an emergency delivery due to the increased relaxation of the esophagus in pregnancy, upward pressure of the uterus on the stomach, and the possibility of general anesthetic in the event of an emergency cesarean. A 2012 Cochrane review pointed out that in recent years, obstetrical anaesthesia has changed considerably, with better general anaesthetic techniques and a greater use of regional anaesthesia and reported "no benefits or harms of restricting foods and fluids during labour in women at low risk of needing anaesthesia." The review suggested "fasting does not guarantee an empty stomach or less acidity" and that "poor nutritional balance may be associated with longer and more painful labours." The review concluded that "women should be free to eat and drink in labour, or not, as they wish."

Perineal shaving
At one time shaving of the perineum, the area around the vagina, was common practice due to the belief that hair removal reduced the risk of infection, made an episiotomy (a surgical cut to enlarge the vaginal entrance) easier, and helped with instrumental deliveries. It is currently less common, though it is still a routine procedure in some countries. A 2009 Cochrane review found no evidence of any clinical benefit with perineal shaving. The review did find side effects including irritation, redness, and multiple superficial scratches from the razor.

Labour induction and elective cesarean
More than 22% of women undergo labour induction the United States, and more than doubled the rate from 1990 to 2006. Induced labour is indicated when either the fetus or woman will benefit compared to continuation of pregnancy, but procedures are often elective. Childbirth by C-Sections increased 50% in the U.S. from 1996 to 2006, and comprise nearly 32% of births in the U.S. and Canada. Non-medically indicated (elective) childbirth before 39 weeks gestation "carry significant risks for the baby with no known benefit to the mother." Hospitals should institute strict monitoring of births to comply with full term (more than 39 weeks gestation) elective induction and C-section guidelines. In review, three hospitals following policy guidelines brought elective early deliveries down 64%, 57%, and 80%. The researchers found many benefits but “no adverse effects” in the health of the mothers and babies at those hospitals.

Health conditions that may warrant induced labour or C-sections include gestational or chronic hypertension, preeclampsia, eclampsia, diabetes, premature rupture of membranes, severe fetal growth restriction, and post-term pregnancy. Cesarean section too may be of benefit to both the mother and baby for certain indications including maternal HIV/AIDS, Foetal abnormality, breech position, foetal distress, multiple gestations, and maternal medical conditions which would be worsened by labour or vaginal birth.

Pitocin is the most commonly used agent for induction in the United States, and is used to induce uterine contractions. Other methods of inducing labour include stripping of the amniotic membrane, artificial rupturing of the amniotic sac (called amniotomy), or stimulation of the nipples of one breast. Ripening of the cervix can be accomplished with the placement of a Foley catheter or the use of synthetic prostaglandins such as misoprostol. A large review of methods of induction was published in 2011.

The American Congress of Obstetricians and Gynecologists (ACOG) guidelines recommend a full evaluation of the maternal-fetal status, the status of the cervix, and at least a 39 completed weeks (full term) of gestation for optimal health of the newborn when considering elective induction of labour. Per these guidelines, the following conditions may be an indication for induction, including:


 * Abruptio placentae
 * Chorioamnionitis
 * Fetal demise
 * Gestational hypertension
 * Preeclampsia or eclampsia
 * Premature rupture of membranes
 * Postterm pregnancy
 * Maternal conditions such as gestational diabetes or chronic kidney disease
 * Fetal compromise such as isoimmunization leading to hemolytic disease of the newborn or oligohydramnios

Induction is also considered for logistical reasons, such as the distance from hospital or psychosocial conditions, but in these instances gestational age confirmation must be done, and the maturity of the fetal lung must be confirmed by testing.

The ACOG also note that contraindications for induced labour are the same as for spontaneous vaginal delivery, including vasa previa, complete placenta praevia, umbilical cord prolapse or active genital herpes simplex infection.

Pain control
Some women prefer to avoid analgesic medication during childbirth. They can still try to alleviate labour pain using psychological preparation, education, massage, acupuncture, TENS unit use, hypnosis, or water therapy in a tub or shower. Some women like to have someone to support them during labour and birth, such as the father of the baby, a family member, a close friend, a partner, or a doula. The human body also has a chemical response to pain, by releasing endorphins. Endorphins are present before, during, and immediately after childbirth. Some homebirth advocates believe that this hormone can induce feelings of pleasure and euphoria during childbirth, reducing the risk of maternal depression some weeks later.
 * Non pharmaceutical

Water birth is an option chosen by some women for pain relief during labour and childbirth, and some studies have shown waterbirth in an uncomplicated pregnancy to reduce the need for analgesia, without evidence of increased risk to mother or newborn. Hot water tubs are available in many hospitals and birthing centres.

Meditation and mind medicine techniques are also used for pain control during labour and delivery. These techniques are used in conjunction with progressive muscle relaxation and many other forms of relaxation for the mind and body to aid in pain control for women during childbirth. One such technique is the use of hypnosis in childbirth. There are a number of organizations that teach women and their partners to use a variety of techniques to assist with labour comfort, without the use of pharmaceuticals.

A new mode of analgesia is sterile water injection placed just underneath the skin in the most painful spots during labour. A control trial in Iran of 0.5mL injections was conducted with normal saline which revealed a statistical superiority with water over saline.

Different measures for pain control have varying degrees of success and side effects to the woman and her baby. In some countries of Europe, doctors commonly prescribe inhaled nitrous oxide gas for pain control, especially as 50% nitrous oxide, 50% oxygen, known as Entonox; 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 such as fentanyl, but if given too close to birth there is a risk of respiratory depression in the infant.
 * Pharmaceutical

Popular medical pain control in hospitals include the regional anesthetics epidurals (EDA), and spinal anaesthesia. Epidural analgesia is a generally safe and effective method of relieving pain in labour, but is associated with longer labour, more operative intervention (particularly instrument delivery), and increases in cost. Generally, pain and cortisol increased throughout labour in women without EDA. Pain and stress hormones rise throughout labour for women without epidurals, while pain, fear, and stress hormones decrease upon administration of epidural analgesia, but may rise again later. Medicine administered via epidural can cross the placenta and enter the bloodstream of the fetus. Epidural analgesia has no statistically significant impact on the risk of caesarean section, and does not appear to have an immediate effect on neonatal status as determined by Apgar scores.

Augmentation
Augmentation is the process of facilitating further labour. Oxytocin has been used to increase the rate of vaginal delivery in those with a slow progress of labour.

Episiotomy
Vaginal tears can occur during childbirth, most often at the vaginal opening as the baby's head passes through, especially if the baby descends quickly. Tears can involve the perineal skin or extend to the muscles and the anal sphincter and anus. The midwife or obstetrician may decide to make a surgical cut to the perineum (episiotomy) to make the baby's birth easier and prevent severe tears that can be difficult to repair. A 2012 Cochrane review compared episiotomy as needed (restrictive) with routine episiotomy to determine the possible benefits and harms for mother and baby. The review found that restrictive episiotomy policies appeared to give a number of benefits compared with using routine episiotomy. Women experienced less severe perineal trauma, less posterior perineal trauma, less suturing and fewer healing complications at seven days with no difference in occurrence of pain, urinary incontinence, painful sex or severe vaginal/perineal trauma after birth, however they found that women experienced more anterior perineal damage with restrictive episiotomy.

Instrumental delivery
Obstetric forceps or ventouse may be used to facilitate childbirth.

Multiple births
In cases of a cephalic presenting twin (first baby head down), twins can often be delivered vaginally. In some cases twin delivery is done in a larger delivery room or in an operating theatre, in the event of complication e.g.
 * Both twins born vaginally—this can occur both presented head first or where one comes head first and the other is breech and/or helped by a forceps/ventouse delivery
 * One twin born vaginally and the other by caesarean section.
 * If the twins are joined at any part of the body—called conjoined twins, delivery is mostly by caesarean section.

Support
Historically women have been attended and supported by other women during labor and birth. However currently, as more women are giving birth in a hospital rather than at home, continuous support has become the exception rather than the norm. Modern obstetric care frequently subjects women to institutional routines, which may have adverse effects on the progress of labor. Supportive care during labor may involve emotional support, comfort measures, and information and advocacy which may promote the physical process of labor as well as women's feelings of control and competence, thus reducing the need for obstetric intervention. The continuous support may be provided either by hospital staff such as nurses or midwives, doulas, or by companions of the woman's choice from her social network. There is increasing evidence to show that the participation of the child's father in the birth leads to better birth and also post-birth outcomes, providing the father does not exhibit excessive anxiety.

A recent Cochrane review involving more than 15,000 women in a wide range of settings and circumstances found that "Women who received continuous labour support were more likely to give birth 'spontaneously', i.e. give birth with neither caesarean nor vacuum nor forceps. In addition, women were less likely to use pain medications, were more likely to be satisfied, and had slightly shorter labours. Their babies were less likely to have low five-minute Apgar scores."

External monitoring
For monitoring of the fetus during childbirth, a simple pinard stethoscope or doppler fetal monitor ("doptone") can be used. A method of external foetal monitoring (EFM) during childbirth is cardiotocography, using a cardiotocograph that consists of two sensors: The heart (cardio) sensor is an ultrasonic sensor, similar to a Doppler fetal monitor, that continuously emits ultrasound and detects motion of the fetal heart by the characteristic of the reflected sound. The pressure-sensitive contraction transducer, called a tocodynamometer (toco) has a flat area that is fixated to the skin by a band around the belly. The pressure required to flatten a section of the wall correlates with the internal pressure, thereby providing an estimate of contraction Monitoring with a cardiotocograph can either be intermittent or continuous.

Invasive monitoring
A mother's waters have to break before invasive monitoring can be used. More invasive monitoring can involve a foetal scalp electrode to give an additional measure of fetal heart activity, and/or intrauterine pressure catheter (IUPC). It can also involve foetal scalp pH testing.

For the mother
Sometimes a mother may need monitoring during childbirth, parameters such as pulse, blood pressure, reflexes and the percentage of oxygen in the blood (pulse oximetry) can be measured.

Collecting stem cells
It is possible to collect two types of stem cells during childbirth: amniotic stem cells or umbilical cord blood stem cells. To collect amniotic stem cells, it is necessary to do amniocentesis before or during the birth. Amniotic stem cells are multipotent and very active, useful for both autologous or donor use. There are private banks in US; the first is Biocell Center in Boston.

Umbilical cord blood stem cells are also active, but less multipotent than amniotic stem cells. There are a lot of banks of cord blood, both private and public and for autologous or eterologous use.

Complications
Childbirth is an inherently dangerous and risky activity, subject to many complications. The "natural" mortality rate of childbirth—where nothing is done to avert maternal death—has been estimated at 1500 deaths per 100,000 births. (See main articles: neonatal death, maternal death). Modern medicine has greatly alleviated the risk of childbirth. In modern Western countries, such as the United States and Sweden, the current maternal mortality rate is around 10 deaths per 100,000 births. As of June 2011, about one third of American births have some complications, "many of which are directly related to the mother's health."

Birthing complications may be maternal or fetal, and long term or short term.

Pre-term
Newborn mortality at 37 weeks may be 2.5 times the number at 40 weeks, and was elevated compared to 38 weeks of gestation. These “early term” births were also associated with increased death during infancy, compared to those occurring at 39 to 41 weeks ("full term"). Researchers found benefits to going full term and “no adverse effects” in the health of the mothers or babies.

Medical researchers find that neonates born before 39 weeks experienced significantly more complications (2.5 times more in one study) compared with those delivered at 39 to 40 weeks. Health problems among babies delivered "pre-term" included respiratory distress, jaundice and low blood sugar. The American Congress of Obstetricians and Gynecologists and medical policy makers review research studies and find increased incidence of suspected or proven sepsis, RDS, Hypoglycemia, need for respiratory support, need for NICU admission, and need for hospitalization > 4 – 5 days. In the case of cesarean sections, rates of respiratory death were 14 times higher in pre-labour at 37 compared with 40 weeks gestation, and 8.2 times higher for pre-labour cesarean at 38 weeks. In this review, no studies found decreased neonatal morbidity due to non-medically indicated (elective) delivery before 39 weeks.

Labour complications
The second stage of labour may be delayed or lengthy due to: Secondary changes may be observed: swelling of the tissues, maternal exhaustion, fetal heart rate abnormalities. Left untreated, severe complications include death of mother and/or baby, and genitovaginal fistula.
 * malpresentation (breech birth (i.e. buttocks or feet first), face, brow, or other)
 * failure of descent of the fetal head through the pelvic brim or the interspinous diameter
 * poor uterine contraction strength
 * active phase arrest
 * cephalo-pelvic disproportion (CPD)
 * shoulder dystocia

Maternal complications
Vaginal birth injury with visible tears or episiotomies are common. Internal tissue tearing as well as nerve damage to the pelvic structures lead in a proportion of women to problems with prolapse, incontinence of stool or urine and sexual dysfunction. Fifteen percent of women become incontinent, to some degree, of stool or urine after normal delivery, this number rising considerably after these women reach menopause. Vaginal birth injury is a necessary, but not sufficient, cause of all non hysterectomy related prolapse in later life. Risk factors for significant vaginal birth injury include:
 * A baby weighing more than 9 pounds.
 * The use of forceps or vacuum for delivery. These markers are more likely to be signals for other abnormalities as forceps or vacuum are not used in normal deliveries.
 * The need to repair large tears after delivery.

Pelvic girdle pain. Hormones and enzymes work together to produce ligamentous relaxation and widening of the symphysis pubis during the last trimester of pregnancy. Most girdle pain occurs before birthing, and is known as diastasis of the pubic symphysis. Predisposing factors for girdle pain include maternal obesity.

Infection remains a major cause of maternal mortality and morbidity in the developing world. The work of Ignaz Semmelweis was seminal in the pathophysiology and treatment of puerperal fever and saved many lives.

Hemorrhage, or heavy blood loss, is still the leading cause of death of birthing mothers in the world today, especially in the developing world. Heavy blood loss leads to hypovolemic shock, insufficient perfusion of vital organs and death if not rapidly treated. Blood transfusion may be life saving. Rare sequelae include Hypopituitarism Sheehan's syndrome.

The maternal mortality rate (MMR) varies from 9 per 100,000 live births in the US and Europe to 900 per 100,000 live births in Sub-Saharan Africa. Every year, more than half a million women die in pregnancy or childbirth.

Mechanical fetal injury
Risk factors for fetal birth injury include fetal macrosomia (big baby), maternal obesity, the need for instrumental delivery, and an inexperienced attendant. Specific situations that can contribute to birth injury include breech presentation and shoulder dystocia. Most fetal birth injuries resolve without long term harm, but brachial plexus injury may lead to Erb's palsy or Klumpke's paralysis.

Neonatal infection
Neonates are prone to infection in the first month of life. Some organisms such as S. agalactiae (Group B Streptococcus) or (GBS) are more prone to cause these occasionally fatal infections. Risk factors for GBS infection include:
 * prematurity (birth before 37 weeks gestation)
 * a sibling who has had a GBS infection
 * prolonged labour or rupture of membranes

Untreated sexually transmitted infections are associated with congenital and perinatal infections in neonates, particularly in the areas where rates of infection remain high. The overall perinatal mortality rate associated with untreated syphilis, for example, is 30%.

Neonatal death
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 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).

A 1983-1989 study by the Texas Department of State Health Services highlighted the differences in neonatal mortality (NMR) between high risk and low risk pregnancies. NMR was 0.57% for doctor-attended high risk births, and 0.19% for low risk births attended by non-nurse midwives. Conversely, some studies demonstrate a higher perinatal mortality rate with assisted home births. Around 80% of pregnancies are low-risk. Factors that may make a birth high risk include prematurity, high blood pressure, gestational diabetes and a previous cesarean section.

Intrapartum asphyxia
Intrapartum asphyxia is the impairment of the delivery of oxygen to the brain and vital tissues during the progress of labour. This may exist in a pregnancy already impaired by maternal or fetal disease, or may rarely arise de novo in labour. This can be termed fetal distress, but this term may be emotive and misleading. True intrapartum asphyxia is not as common as previously believed, and is usually accompanied by multiple other symptoms during the immediate period after delivery. Monitoring might show up problems during birthing, but the interpretation and use of monitoring devices is complex and prone to misinterpretation. Intrapartum asphyxia can cause long-term impairment, particularly when this results in tissue damage through encephalopathy.

Associated professions


Different categories of birth attendants may provide support and care during pregnancy and childbirth, although there are important differences across categories based on professional training and skills, practice regulations, as well as nature of care delivered.

“Childbirth educators” are instructors who aim to educate pregnant women and their partners about the nature of pregnancy, labour signs and stages, techniques for giving birth, breastfeeding and newborn baby care. In the United States and elsewhere, classes for training as a childbirth educator can be found in hospital settings or through many independent certifying organizations such as Birthing From Within, BirthWorks, The Bradley Method, Birth Arts International, CAPPA, HypBirth, HypnoBabies, HypnoBirthing, ICTC, ICEA, Lamaze, etc. Each organization teaches its own curriculum and each emphasizes different techniques. Information about each can be obtained through their individual websites.

Doulas are assistants who support mothers during pregnancy, labour, birth, and postpartum. They are not medical attendants; rather, they provide emotional support and non-medical pain relief for women during labour. Like childbirth educators and other assistive personnel, certification to become a doula is not compulsory, thus, anyone can call themself a doula or a childbirth educator.

Midwives are autonomous practitioners who provide basic and emergency health care before, during and after pregnancy and childbirth, generally to women with low-risk pregnancies. Midwives are trained to assist during labour and birth, either through direct-entry or nurse-midwifery education programs. Jurisdictions where midwifery is a regulated profession will typically have a registering and disciplinary body for quality control, such as the College of Midwives of British Columbia (CMBC) in Canada or the Nursing and Midwifery Council (NMC) in the United Kingdom.

In jurisdictions where midwifery is not a regulated profession, traditional or lay midwives may assist women during childbirth, although they do not typically receive formal health care education and training.

Medical doctors who practice obstetrics include categorically specialized obstetricians; family practitioners and general practitioners whose training, skills and practices include obstetrics; and in some contexts general surgeons. These physicians and surgeons variously provide care across the whole spectrum of normal and abnormal births and pathological labour conditions. Categorically specialized obstetricians are qualified surgeons, so they can undertake surgical procedures relating to childbirth. Some family practitioners or general practitioners also perform obstetrical surgery. Obstetrical procedures include cesarean sections, episiotomies, and assisted delivery. Categorical specialists in obstetrics are commonly dually trained in obstetrics and gynecology (OB/GYN), and may provide other medical and surgical gynecological care, and may incorporate more general, well-woman, primary care elements in their practices. Maternal-fetal medicine specialists are obstetrician/gynecologists subspecialized in managing and treating high-risk pregnancy and delivery.

Anaesthetists or anesthesiologists are medical doctors who specialise in pain relief and the use of drugs to facilitate surgery and other painful procedures. They may contribute to the care of a woman in labour by performing epidurals or by providing anaesthesia (often spinal anaesthesia) for Cesarean section or forceps delivery.

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

Facilities
Following are facilities that are particularly intended to house women during childbirth:
 * A labour ward, also called a delivery ward or labour and delivery, is generally a department of a hospital that focuses on providing health care to women and their children during childbirth. It is generally closely linked to the hospital's neonatal intensive care unit and/or obstetric surgery unit if present. A maternity ward or maternity unit may include facilities both for childbirth and for postpartum rest and observation of mothers in normal as well as complicated cases.
 * A birthing center generally presents a simulated home-like environment. Birthing centers may be located on hospital grounds or "free standing" (i.e., not hospital-affiliated).

In addition, it is possible to have a home birth.

Society and culture
Childbirth routinely occurs in hospitals in much of Western society. Before the 20th century and in some countries to the present day it has more typically occurred at home.

In Western and other cultures, age is reckoned from the date of birth, and sometimes the birthday is celebrated annually. East Asian age reckoning starts newborns at "1", incrementing each Lunar New Year.

Some families view the placenta as a special part of birth, since it has been the child's life support for so many months.The placenta may be eaten by the newborn's family, ceremonially or otherwise (for nutrition; the great majority of animals in fact do this naturally). Most recently there is a category of birth professionals available who will encapsulate placenta for use as placenta medicine by postpartum mothers.

The exact location in which childbirth takes place is an important factor in determining nationality, in particular for birth aboard aircraft and ships.