The brachial plexus is the bundle of nerves that runs from the neck to the hand and controls the motion of the arm and hand. The brachial plexus may be stretched and damaged during a difficult delivery. In minor cases, the nerves heal and full use of the hand and arm is recovered. In more severe cases, the child may suffer permanent nerve damage and may not have full use of the shoulder, arm, or hand. Brachial plexus injuries occur in 1-3 children per 1,000 live births.

"See Erbs Palsy and Klumpke’s Palsy."

Bone fractures can occur during a difficult delivery. Fracture of the clavicle is the most common birth injury.

Birth trauma (BT) refers to damage of the tissues and organs of a newly delivered child, often as a result of physical pressure or trauma during childbirth. The term also encompasses the long term consequences, often of a cognitive nature, of damage to the brain or cranium. Medical study of birth trauma dates to the 16th century, and the morphological consequences of mishandled delivery are described in Renaissance-era medical literature. Birth injury occupies a unique area of concern and study in the medical canon. In ICD-10 "birth trauma" occupied 49 individual codes (P10-Р15).

However, there are often clear distinctions to be made between brain damage caused by birth trauma and that induced by intrauterine asphyxia. It is also crucial to distinguish between "birth trauma" and "birth injury". Birth injuries encompass any systemic damages incurred during delivery (hypoxic, toxic, biochemical, infection factors, etc.), but "birth trauma" focuses largely on mechanical damage. Caput succedaneum, subcutaneous hemorrhages, small subperiostal hemorrhages, hemorrhages along the displacements of cranial bones, intradural bleedings, subcapsular haematomas of liver, are among the more commonly reported birth injuries. Birth trauma, on the other hand, encompasses the enduring side effects of physical birth injuries, including the ensuing compensatory and adaptive mechanisms and the development of pathological processes (pathogenesis) after the damage.

Types of breech depend on how the baby’s legs are lying.

- A frank breech (otherwise known as an extended breech) is where the baby’s legs are up next to its abdomen, with its knees straight and its feet next to its ears. This is the most common type of breech.

- A complete breech (flexed) breech is when the baby appears as though it is sitting crossed-legged with its legs bent at the hips and knees.

- A footling breech is when one or both of the baby’s feet are born first instead of the pelvis. This is more common in babies born prematurely or before their due date.

In addition to the above, breech births in which the sacrum is the fetal denominator can be classified by the position of a fetus. Thus sacro-anterior, sacro-transverse and sacro-posterior positions all exist, but left sacro-anterior is the most common presentation. Sacro-anterior indicates an easier delivery compared to other forms.

A breech birth occurs when a baby is born bottom first instead of head first. Around 3-5% of pregnant women at term (37–40 weeks pregnant) will have a breech baby.

Most babies in the breech position are born by a caesarean section because it is seen as safer than being born vaginally.

As most breech babies are delivered by caesarean section in developed countries, doctors and midwives may lose the skills required to safely assist women giving birth to a breech baby vaginally. Delivering all breech babies by caesarean section in developing countries may be very difficult to implement or even impossible as there are not always resources available to provide this service.

The major concern of shoulder dystocia is damage to the upper brachial plexus nerves. These supply the sensory and motor components of the shoulder, arm and hands. The ventral roots (motor pathway) are most prone to injury. The cause of injury to the baby is debated, but a probable mechanism is manual stretching of the nerves, which in itself can cause injury. Excess tension may physically tear the nerve roots out from the neonatal spinal column, resulting in total dysfunction.

- Klumpke paralysis

- Erb's Palsy

- Fetal hypoxia

- Fetal death

- Cerebral palsy

- Maternal post partum hemorrhage (11%)

- Vaginal lacerations and 3rd/4th degree tears, extended episiotomies

- uterine rupture

While any number of injuries may occur during the birthing process. A number of specific conditions are well described. Brachial plexus palsy occurs in 0.4 to 5.1 infants per 1000 live birth. Head trauma and brain damage during delivery can lead to a number of conditions include: caput succedaneum, cephalohematoma, subgaleal hemorrhage, subdural hemorrhage, subarachnoid hemorrhage, epidural hemorrhage, and intraventricular hemorrhage.

The most common fracture during delivery is that of the clavicle (0.5%).

Shoulder dystocia is a specific case of obstructed labour whereby after the delivery of the head, the anterior shoulder of the infant cannot pass below, or requires significant manipulation to pass below, the pubic symphysis. It is diagnosed when the shoulders fail to deliver shortly after the fetal head. Shoulder dystocia is an obstetric emergency, and fetal demise can occur if the infant is not delivered, due to compression of the umbilical cord within the birth canal. It occurs in approximately 0.3-1% of vaginal births.

Preterm infants usually show physical signs of prematurity in reverse proportion to the gestational age. As a result, they are at risk for numerous medical problems affecting different organ systems.

- Neurological problems include apnea of prematurity, hypoxic-ischemic encephalopathy (HIE), retinopathy of prematurity (ROP), developmental disability, transient hyperammonemia of the newborn, cerebral palsy and intraventricular hemorrhage, the latter affecting 25 percent of babies born preterm, usually before 32 weeks of pregnancy. Mild brain bleeds usually leave no or few lasting complications, but severe bleeds often result in brain damage or even death. Neurodevelopmental problems have been linked to lack of maternal thyroid hormones, at a time when their own thyroid is unable to meet postnatal needs.

- Cardiovascular complications may arise from the failure of the ductus arteriosus to close after birth: patent ductus arteriosus (PDA).

- Respiratory problems are common, specifically the respiratory distress syndrome (RDS or IRDS) (previously called hyaline membrane disease). Another problem can be chronic lung disease (previously called bronchopulmonary dysplasia or BPD).

- Gastrointestinal and metabolic issues can arise from neonatal hypoglycemia, feeding difficulties, rickets of prematurity, hypocalcemia, inguinal hernia, and necrotizing enterocolitis (NEC).

- Hematologic complications include anemia of prematurity, thrombocytopenia, and hyperbilirubinemia (jaundice) that can lead to kernicterus.

- Infection, including sepsis, pneumonia, and urinary tract infection

A study of 241 children born between 22 and 25 weeks who were currently of school age found that 46 percent had severe or moderate disabilities such as cerebral palsy, vision or hearing loss and learning problems. 34 percent were mildly disabled and 20 percent had no disabilities, while 12 percent had disabling cerebral palsy.

Preterm birth causes a range of problems.

The main categories of causes of preterm birth are preterm labor induction and spontaneous preterm labor. Signs and symptoms of preterm labor include four or more uterine contractions in one hour. In contrast to false labour, true labor is accompanied by cervical dilatation and effacement. Also, vaginal bleeding in the third trimester, heavy pressure in the pelvis, or abdominal or back pain could be indicators that a preterm birth is about to occur. A watery discharge from the vagina may indicate premature rupture of the membranes that surround the baby. While the rupture of the membranes may not be followed by labor, usually delivery is indicated as infection (chorioamnionitis) is a serious threat to both fetus and mother. In some cases, the cervix dilates prematurely without pain or perceived contractions, so that the mother may not have warning signs until very late in the birthing process.

A review into using uterine monitoring at home to detect contractions and possible preterm births in women at higher risk of having a preterm baby found that it did not reduce the number of preterm births. The research included in the review was poor quality but it showed that home monitoring may increase the number of unplanned antenatal visits and may reduce the number of babies admitted to special care when compared with women receiving normal antenatal care.

Large for gestational age (LGA) is an indication of high prenatal growth rate.

LGA is often defined as a weight, length, or head circumference that lies above the 90th percentile for that gestational age. However, it has been suggested that the definition be restricted to infants with birth weights greater than the 97th percentile (2 standard deviations above the mean) as this more accurately describes infants who are at greatest risk for perinatal morbidity and mortality.

Macrosomia, which literally means "long body", is sometimes confused with LGA. Some experts consider a baby to be big when it weighs more than at birth, and others say a baby is big if it weighs more than . A baby is also called “large for gestational age” if its weight is greater than the 90th percentile at birth.

LGA and macrosomia cannot be diagnosed until after birth, as it is impossible to accurately estimate the size and weight of a child in the womb. Babies that are large for gestational age throughout the pregnancy may be suspected because of an ultrasound, but fetal weight estimations in pregnancy are quite imprecise. For non-diabetic women, ultrasounds and care providers are equally inaccurate at predicting whether or not a baby will be big. If an ultrasound or a care provider predicts a big baby, they will be wrong half the time.

Although big babies are born to only 1 out of 10 women, the 2013 Listening to Mothers Survey found that 1 out of 3 American women were told that their babies were too big. In the end, the average birth weight of these suspected “big babies” was only . In the end, care provider concerns about a suspected big baby were the fourth-most common reason for an induction (16% of all inductions), and the fifth-most common reason for a C-section (9% of all C-sections). This treatment is not based on current best evidence.

Research has consistently shown that, as far as birth complications are concerned, the care provider’s perception that a baby is big is more harmful than an actual big baby by itself. In a 2008 study, researchers compared what happened to women who were suspected of having a big baby to what happened to women who were not suspected of having a big baby—but who ended up having one. In the end, women who were suspected of having a big baby (and actually had one) had a triple in the induction rate, more than triple the C-section rate, and a quadrupling of the maternal complication rate, compared to women who were not suspected of having a big baby but who had one anyway.

Complications were most often due to C-sections and included bleeding (hemorrhage), wound infection, wound separation, fever, and need for antibiotics. There were no differences in shoulder dystocia between the two groups. In other words, when a care provider “suspected” a big baby (as compared to not knowing the baby was going to be big), this tripled the C-section rates and made mothers more likely to experience complications, without improving the health of babies.

Congenital amputation is birth without a limb or limbs, or without a part of a limb or limbs.

It is known to be caused by blood clots forming in the fetus while "in utero" (vascular insult) and from amniotic band syndrome: fibrous bands of the amnion that constrict foetal limbs to such an extent that they fail to form or actually fall off due to missing blood supply. Congenital amputation can also occur due to maternal exposure to teratogens during pregnancy.

Hyperemesis gravidarum is the presence of severe and persistent vomiting, causing dehydration and weight loss. It is more severe than the more common morning sickness and is estimated to affect 0.5–2.0% of pregnant women.

Delayed motor development of infants affected by PVL has been demonstrated in multiple studies. One of the earliest markers of developmental delays can be seen in the leg movements of affected infants, as early as one month of age. Those with white matter injury often exhibit "tight coupling" of leg joints (all extending or all flexing) much longer than other infants (premature and full-term). Additionally, infants with PVL may not be able to assume the same positions for sleeping, playing, and feeding as premature or full-term children of the same age. These developmental delays can continue throughout infancy, childhood, and adulthood.

A combination of postural changes, the growing baby, unstable pelvic joints under the influence of pregnancy hormones, and changes in the centre of gravity can all add to the varying degrees of pain or discomfort. In some cases it can come on suddenly or following a fall, sudden abduction of the thighs (opening too wide too quickly) or an action that has strained the joint.

PGP can begin as early as the first trimester of pregnancy. Pain is usually felt low down over the symphyseal joint, and this area may be extremely tender to the touch. Pain may also be felt in the hips, groin and lower abdomen and can radiate down the inner thighs. Women suffering from PGP may begin to waddle or shuffle, and may be aware of an audible clicking sound coming from the pelvis. PGP can develop slowly during pregnancy, gradually gaining in severity as the pregnancy progresses.

During pregnancy and postpartum, the symphyseal gap can be felt moving or straining when walking, climbing stairs or turning over in bed; these activities can be difficult or even impossible. The pain may remain static, e.g., in one place such as the front of the pelvis, producing the feeling of having been kicked; in other cases it may start in one area and move to other areas. It is also possible that a woman may experience a combination of symptoms.

Any weight bearing activity has the potential of aggravating an already unstable pelvis, producing symptoms that may limit the ability of the woman to carry out many daily activities. She may experience pain involving movements such as dressing, getting in and out of the bath, rolling in bed, climbing the stairs or sexual activity. Pain may also be present when lifting, carrying, pushing or pulling.

The symptoms (and their severity) experienced by women with PGP vary, but include:

- Present swelling and/or inflammation over joint.

- Difficulty lifting leg.

- Pain pulling legs apart.

- Inability to stand on one leg.

- Inability to transfer weight through pelvis and legs.

- Pain in hips and/or restriction of hip movement.

- Transferred nerve pain down leg.

- Can be associated with bladder and/or bowel dysfunction.

- A feeling of the symphysis pubis giving way.

- Stooped back when standing.

- Malalignment of pelvic and/or back joints.

- Struggle to sit or stand.

- Pain may also radiate down the inner thighs.

- Waddling or shuffling gait.

- Audible ‘clicking’ sound coming from the pelvis.

It is often impossible to identify PVL based on the patient’s physical or behavioral characteristics. The white matter in the periventricular regions is involved heavily in motor control, and so individuals with PVL often exhibit motor problems. However, since healthy newborns (especially premature infants) can perform very few specific motor tasks, early deficits are very difficult to identify. As the individual develops, the areas and extent of problems caused by PVL can begin to be identified; however, these problems are usually found after an initial diagnosis has been made.

The extent of signs is strongly dependent on the extent of white matter damage: minor damage leads to only minor deficits or delays, while significant white matter damage can cause severe problems with motor coordination or organ function. Some of the most frequent signs include delayed motor development, vision deficits, apneas, low heart rates, and seizures.

Complications of pregnancy are health problems that are caused by pregnancy. In the immediate postpartum period, 87% to 94% of women report at least one health problem. Long term health problems (persisting after 6 months postpartum) are reported by 31% of women. Severe complications of pregnancy are present in 1.6% of mothers in the US and in 1.5% of mothers in Canada. The relationship between age and complications of pregnancy are now being researched with greater impetus.

In 2013, complications of pregnancy resulted globally in 293,000 deaths, down from 377,000 deaths in 1990. The most common causes of maternal mortality are maternal bleeding, maternal sepsis and other infections, hypertensive diseases of pregnancy, obstructed labor, and , which includes miscarriage, ectopic pregnancy, and elective abortion.

There is no clear distinction between complications of pregnancy and symptoms and discomforts of pregnancy. However, the latter do not significantly interfere with activities of daily living or pose any significant threat to the health of the mother or baby. Still, in some cases the same basic feature can manifest as either a discomfort or a complication depending on the severity. For example, mild nausea may merely be a discomfort (morning sickness), but if severe and with vomiting causing water-electrolyte imbalance it can be classified as a pregnancy complication (hyperemesis gravidarum).

PGP in pregnancy seriously interferes with participation in society and activities of daily life; the average sick leave due to posterior pelvic pain during pregnancy is 7 to 12 weeks.

In some cases women with PGP may also experience emotional problems such as anxiety over the cause of pain, resentment, anger, lack of self-esteem, frustration and depression; she is three times more likely to suffer postpartum depressive symptoms. Other psychosocial risk factors associated with woman experiencing PGP include higher level of stress, low job satisfaction and poorer relationship with spouse.

Symptoms vary depending on whether the spinal cord, brain stem, nerves or their blood supply is affected by the pressure.

Symptoms become apparent when the neck is bent. They include:

- Posterior head pain

- Neck weakness

- Periods of confusion

- Dysarthria (difficulty swallowing or talking due to loss of muscle control)

- Dizziness

- Loss of sensation

- Cranial nerve disturbance

- Loss of the ability to know how joints are positioned

- Lhermitte's sign ('electric shock sensation' down spine and/or to the extremities when the neck is flexed forward)

- Weakness of the arms and legs

- Orthostatic hypotension

- Patients will go into a pool and notice that below their belly button the water is not as cold as it is above.

Complications from this can include hydrocephalus, pseudotumor cerebri or syringomyelia because it blocks the flow of fluid around the brain and spinal cord.

Perinatal asphyxia, neonatal asphyxia or birth asphyxia is the medical condition resulting from deprivation of oxygen to a newborn infant that lasts long enough during the birth process to cause physical harm, usually to the brain. Hypoxic damage can occur to most of the infant's organs (heart, lungs, liver, gut, kidneys), but brain damage is of most concern and perhaps the least likely to quickly or completely heal. In more pronounced cases, an infant will survive, but with damage to the brain manifested as either mental, such as developmental delay or intellectual disability, or physical, such as spasticity.

It results most commonly from a drop in maternal blood pressure or some other substantial interference with blood flow to the infant's brain during delivery. This can occur due to inadequate circulation or perfusion, impaired respiratory effort, or inadequate ventilation. Perinatal asphyxia happens in 2 to 10 per 1000 newborns that are born at term, and more for those that are born prematurely. WHO estimates that 4 million neonatal deaths occur yearly due to birth asphyxia, representing 38% of deaths of children under 5 years of age.

Perinatal asphyxia can be the cause of hypoxic ischemic encephalopathy or intraventricular hemorrhage, especially in preterm births. An infant suffering severe perinatal asphyxia usually has poor color (cyanosis), perfusion, responsiveness, muscle tone, and respiratory effort, as reflected in a low 5 minute Apgar score. Extreme degrees of asphyxia can cause cardiac arrest and death. If resuscitation is successful, the infant is usually transferred to a neonatal intensive care unit.

There has long been a scientific debate over whether newborn infants with asphyxia should be resuscitated with 100% oxygen or normal air. It has been demonstrated that high concentrations of oxygen lead to generation of oxygen free radicals, which have a role in reperfusion injury after asphyxia. Research by Ola Didrik Saugstad and others led to new international guidelines on newborn resuscitation in 2010, recommending the use of normal air instead of 100% oxygen.

There is considerable controversy over the diagnosis of birth asphyxia due to medicolegal reasons. Because of its lack of precision, the term is eschewed in modern obstetrics.

Intrauterine hypoxia occurs when the fetus is deprived of an adequate supply of oxygen. It may be due to a variety of reasons such as prolapse or occlusion of the umbilical cord, placental infarction and maternal smoking. Intrauterine growth restriction (IUGR) may cause or be the result of hypoxia. Intrauterine hypoxia can cause cellular damage that occurs within the central nervous system (the brain and spinal cord). This results in an increased mortality rate, including an increased risk of sudden infant death syndrome (SIDS). Oxygen deprivation in the fetus and neonate have been implicated as either a primary or as a contributing risk factor in numerous neurological and neuropsychiatric disorders such as epilepsy, ADHD, eating disorders and cerebral palsy.

Subcutaneous fat necrosis of the newborn (SCFN or SFN) is a rare form of lobular panniculitis occurring in newborns that is usually self-remitting and non-recurring. Proposed causes include perinatal stress, local trauma, hypoxia and hypothermia, though the exact cause is unknown. It has been suggested that the brown fat seen in newborns is more sensitive to hypoxic injury than fat seen in adults, and that such hypoxia, usually in the context of a complicated birth, leads to the fat necrosis. Complications can include hypercalcemia, hyperlipidemia and thrombocytopenia, and can present months after the onset of SCFN symptoms.

Signs and symptoms may include a limp or paralyzed arm, lack of muscle control in the arm, hand, or wrist, and lack of feeling or sensation in the arm or hand. Although several mechanisms account for brachial plexus injuries, the most common is nerve compression or stretch. Infants, in particular, may suffer brachial plexus injuries during delivery and these present with typical patterns of weakness, depending on which portion of the brachial plexus is involved. The most severe form of injury is nerve root avulsion, which usually accompanies high-velocity impacts that commonly occur during motor-vehicle collisions or bicycle accidents.

The most obvious sign that meconium has been passed during or before labor is the greenish or yellowish appearance of the amniotic fluid. The infant's skin, umbilical cord, or nailbeds may be stained green if the meconium was passed a considerable amount of time before birth. These symptoms alone do not necessarily indicate that the baby has inhaled in the fluid by gasping in utero or after birth. After birth, rapid or labored breathing, cyanosis, slow heartbeat, a barrel-shaped chest or low Apgar score are all signs of the syndrome. Inhalation can be confirmed by one or more tests such as using a stethoscope to listen for abnormal lung sounds (diffuse 'wet' crackles and rhonchi), performing blood gas tests to confirm a severe loss of lung function (respiratory acidosis as a consequence of hypercapnia), and using chest X-rays to look for patchy or streaked areas on the lungs. Infants who have inhaled meconium may develop respiratory distress syndrome often requiring ventilatory support. Complications of MAS include pneumothorax and persistent pulmonary hypertension of the newborn.