Childbirth

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Childbirth, also known as labour or delivery, is the ending of pregnancy where one or more babies leaves the uterus by passing through the vagina or by Caesarean section. In 2015, there were about 135 million births globally.About 15 million were born before 37 weeks of gestation, while between 3 and 12% were born after 42 weeks. In the developed world most deliveries occur in hospitals, while in the developing world most births take place at home with the support of a traditional birth attendant.

The most common way of childbirth is a vaginal delivery. It involves three stages of labour: the shortening and opening of the cervix during the first stage, descent and birth of the baby during the second stage, and the delivery of the placenta during the third stage.

The first stage begins with crampy abdominal or back pain that lasts around half a minute and occurs every 10 to 30 minutes.[ The pain becomes stronger and closer together over time. The second stage ends when the infant is fully expelled. In the third stage, the delivery of the placenta, delayed clamping of the umbilical cord is generally recommended. As of 2014, all major health organisations advise that immediately following vaginal birth, or as soon as the mother is alert and responsive after a Caesarean section, that the infant be placed on the mother’s chest, termed skin-to-skin contact, delaying routine procedures for at least one to two hours or until the baby has had its first breastfeeding.

Most babies are born head first; however about 4% are born feet or buttocks first, known as breech. Typically the head enters the pelvis facing to one side, and then rotates to face down. During labour, the woman giving birth can generally eat and move around as they like. A number of methods can help with pain, such as relaxation techniques, opioids, and spinal blocks. While making a cut to the opening of the vagina, known as an episiotomy, is common, it is generally not needed. In 2012, about 23 million deliveries occurred by Caesarean section, an operation on the abdomen.

Each year, complications from pregnancy and childbirth result in about 500,000 birthing deaths, seven million women have serious long-term problems, and 50 million women giving birth have negative health outcomes following delivery. Most of these occur in the developing world. Specific complications include obstructed labour, postpartum bleeding, eclampsia, and postpartum infection.Complications in the baby may include lack of oxygen at birth, birth trauma, prematurity, and infections.

Signs and symptoms

The most prominent sign of labour is strong repetitive uterine contractions. The distress levels reported by labouring woman vary widely. They appear to be influenced by fear and anxiety levels, experience with prior childbirth, cultural ideas of childbirth pain, mobility during labour, and the support received during labour.

Personal expectations, the amount of support from caregivers, quality of the caregiver-patient relationship, and involvement in decision-making are more important in mother’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 giving birth are often encouraged to refrain from screaming. However, moaning and grunting may be encouraged to help lessen pain. Crowning may be experienced as an intense stretching and burning. Even those who show little reaction to labour pains, in comparison to others, show a substantially severe reaction to crowning (the appearance of the baby's head).[citation needed]

Back labour is a term for specific pain occurring in the lower back, just above the tailbone, during childbirth.

Psychological

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 labour when the fetus stimulates the cervix and vagina, and it is believed that it plays a major role in the bonding of a birther to their infant and in the establishment of "maternal" behaviour. The act of nursing a child also causes a release of oxytocin.

Between 70% and 80% of woman who give birth in the United States report some feelings of sadness or "baby blues" after giving birth.[medical citation needed] 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. Preventive group therapy has proven effective as a prophylactic treatment for postpartum depression.

Vaginal birth

Humans are bipedal with an erect stance. 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, in women, 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 manoeuvres in order to pass through the ring of the mother's pelvis.

Six phases of a typical vertex or cephalic (head-first presentation) delivery:

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.

Descent and flexion of the fetal head.

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.

Delivery by extension. The fetal head is bowed, chin on chest, so that the back or crown of its head leads the way through the birth canal, until the back of its neck presses against the pubic bone and its chin leaves its chest, extending the neck – as if to look up, and the rest of its head passes out of the birth canal.

Restitution. The fetal head turns through 45 degrees to restore its normal relationship with the shoulders, which are still at an angle.

External rotation. The shoulders repeat the corkscrew movements of the head, which can be seen in the final movements of the fetal head.

The vagina is called a 'birth canal' when the baby enters this passage.

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.

Cervical ripening is the physical and chemical changes in the cervix to prepare it for the stretching that will take place as the fetus moves out of the uterus and into the birth canal. A scoring system called a Bishop score can be used to judge the degree of cervical ripening in order to predict the timing of labour and delivery of the infant or for women at risk for preterm labour. It is also used to judge when a woman will respond to induction of labour for a postdate pregnancy or other medical reasons. There are several methods of inducing cervical ripening which will allow the uterine contractions to effectively dilate the cervix.

Labour induction and elective Caesarean section

In many cases and with increasing frequency, childbirth is achieved through labour induction or caesarean section. Labour induction is the process or treatment that stimulates childbirth and delivery. Inducing labour can be accomplished with pharmaceutical or non-pharmaceutical methods. Inductions are most often performed either with prostaglandin drug treatment alone, or with a combination of prostaglandin and intravenous oxytocin treatment. Caesarean section 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 US from 1996 to 2006. In 2011, 32.8 per cent of births in the US were delivered by cesarean section. Induced births and elective cesarean before 39 weeks can be harmful to the neonate as well as harmful or without benefit to the mother. Therefore, many guidelines recommend against non-medically required induced births and elective cesarean before 39 weeks. The 2012 rate of labour induction in the United States was 23.3 per cent, and has more than doubled from 1990 to 2010. 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, indications for induction may include:

Abruptio placentae

Chorioamnionitis

Fetal compromise such as isoimmunisation leading to haemolytic disease of the newborn or oligohydramnios Fetal demise

Gestational hypertension

Maternal conditions such as gestational diabetes or chronic kidney disease

Preeclampsia or eclampsia

Premature rupture of membranes

Postterm pregnancy

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.