Childbirth
Childbirth, also known as labour, parturition, and delivery, is the completion of pregnancy, where one or more fetuses exits the internal environment of the mother vaginally or via caesarean section and becomes a newborn to the world. In 2019, there were about 140.11 million human births globally. In developed countries, most births occur in hospitals, while in developing countries most are home births.
Vaginal birth is the most common mode of birth worldwide. It involves four stages of labour: the shortening and opening of the cervix during the first stage, descent and birth of the baby during the second, the birth of the placenta during the third, and the recovery of the mother and infant during the fourth stage, which is referred to as the postpartum. The first stage is characterised by abdominal partying or also back pain in the case of back labour, that typically lasts half a minute and occurs every 10 to 30 minutes. Contractions gradually become stronger and closer together. Since the pain of childbirth correlates with contractions, the pain becomes more frequent and strong as the labour progresses. The second stage ends when the infant is fully expelled. The third stage is the birth of the placenta. The fourth stage of labour involves the recovery of the mother, delayed clamping of the umbilical cord, and monitoring of the neonate. All major health organisations advise that immediately after giving birth, regardless of the mode of birth, that the infant be placed on the mother's chest, and to delay any other routine procedures for at least one to two hours or until the baby has had its first breastfeeding.
Vaginal delivery is generally recommended as a first option. Cesarean section can lead to increased risk of complications and a significantly slower recovery. There are also many natural benefits of a vaginal delivery in both mother and baby. Various methods may help with pain, such as relaxation techniques, opioids, and spinal blocks. It is best practice to limit the amount of interventions that occur during labour and delivery such as an elective cesarean section. However in some cases a scheduled cesarean section must be planned for a successful delivery and recovery of the mother. An emergency cesarean section may be recommended if unexpected complications occur or little to no progression through the birthing canal is observed in a vaginal delivery.
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 which occur in the developing world. Complications in the mother include obstructed labour, postpartum bleeding, eclampsia, and postpartum infection. Complications in the baby include lack of oxygen at birth, birth trauma, and prematurity.
Signs and symptoms
The most prominent sign of labour is strong repetitive uterine contractions. Pain in contractions has been described as feeling similar to very strong menstrual cramps. Crowning, when the baby's head becomes visible, may be experienced as an intense stretching and burning.Back labour is a complication that occurs during childbirth when the feet or the bottom of the baby is visible first, instead of the being born head down. This leads to more intense contractions, and causes pain in the lower back that persists between contractions as the back of the fetus' head exerts pressure on the mother's sacrum.
Another prominent sign of labour is the rupture of membranes, commonly known as "water breaking". During pregnancy, a baby is surrounded and cushioned by a fluid-filled sac. Usually the sac ruptures at the beginning of or during labour. It may cause a gush of fluid or leak in an intermittent or constant flow of small amounts from a woman's vagina. The fluid is clear or pale yellow. If the amniotic sac has not yet broken during labour the health care provider may break it in a technique called an amniotomy. In an amniotomy a thin plastic hook is used to make a small opening in the sac, causing the water to break. If the sac breaks before labour starts, it's called a prelabour rupture of membranes. Contractions will typically start within 24 hours after the water breaks. If not, the care provider will generally begin labour induction within 24 to 48 hours. If the baby is preterm, the healthcare provider may use a medication to delay delivery.
Labour pain
Labor pains have both visceral and somatic components. During the first and second stages of labour, uterine contractions cause stretching and opening of the cervix. This in turn triggers visceral pain in the inner cervix and lower segment of the spine. Somatic pain is triggered at the end of the first and second stages of labour by pain receptors that supply the nerves on the vaginal surface of the cervix, resulting from stretching, distention, and tearing of the vagina, perineum, and pelvic floor. Compared to visceral pain, somatic pain is more resistant to opioid pain medication. Nitrous oxide may be used in hospitals and birthing centers for this reason.Beyond physical pain, there are also well-documented biocultural and psychosocial aspects of labour pain and pain management. Pain is experienced distinctly by different cultures and there are various culturally-relevant interventions than can lessen labour pain, such as having extended female family members present during childbirth. Labour might be less painful in subsequent births, and this has been associated with lessened fear.
Pain management techniques during labour can include pain relief with medication or coping techniques.
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. 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 mother to her infant and in the establishment of maternal behaviour. The father of the child also has an increase in oxytocin levels following contact with the infant and parents with higher oxytocin levels show being more responsive and "in synch" in their interactions with their infant. The act of nursing a child also causes a release of oxytocin to help the baby get milk more easily from the nipple.Vaginal birth
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. 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. At +3 and +4 the presenting part is at the perineum and can be seen.The baby's head may temporarily change shape 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 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 postterm pregnancy or other medical reasons. There are several methods of inducing cervical ripening which will allow the uterine contractions to effectively dilate the cervix.
Vaginal delivery involves four stages of labour: the shortening and opening of the cervix during the first stage, descent and birth of the baby during the second, the delivery of the placenta during the third, and the fourth stage of recovery which lasts until two hours after the delivery. The first stage is characterised by abdominal cramping or back pain that typically lasts around half a minute and occurs every 10 to 30 minutes. The contractions gradually becomes stronger and closer together. The second stage ends when the infant is fully expelled. In the third stage, the delivery of the placenta. The fourth stage of labour involves recovery, the uterus beginning to contract to pre-pregnancy state, delayed clamping of the umbilical cord, and monitoring of the neonatal tone and vitals. All major health organisations advise that immediately following a live birth, regardless of the delivery method, that the infant be placed on the mother's chest, termed skin-to-skin contact, and delaying routine procedures for at least one to two hours or until the baby has had its first breastfeeding.
Onset of labour
Definitions of the onset of labour include:- Regular uterine contractions at least every six minutes with evidence of change in cervical dilation or cervical effacement between consecutive digital examinations.
- Regular contractions occurring less than 10 minutes apart and progressive cervical dilation or cervical effacement.
- At least three painful regular uterine contractions during a 10-minute period, each lasting more than 45 seconds.
While inside the uterus the baby is enclosed in a fluid-filled membrane called the amniotic sac. Shortly before, at the beginning of, or during labour the sac ruptures, commonly known as the "water breaking". Once the sac ruptures the baby is at risk for infection and the mother's medical team will assess the need to induce labour if it has not started within the time they believe to be safe for the infant.