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.

The signs of sepsis are non-specific and include:

- Body temperature changes

- Breathing problems

- Diarrhea

- Low blood sugar (hypoglycemia)

- Reduced movements

- Reduced sucking

- Seizures

- Bradycardia

- Swollen belly area

- Vomiting

- Yellow skin and whites of the eyes (jaundice)

A heart rate above 160 can also be an indicator of sepsis, this tachycardia can present up to 24 hours before the onset of other signs.

Transient tachypnea of the newborn (TTN, TTNB, or "transitory tachypnea of newborn") is a respiratory problem that can be seen in the newborn shortly after delivery. Amongst causes of respiratory distress in term neonates, it is the most common. It consists of a period of rapid breathing (higher than the normal range of 30-60 times per minute). It is likely due to amniotic fluid remaining in the lungs after birth. Usually, this condition resolves over 24–48 hours. Treatment is supportive and may include supplemental oxygen and antibiotics. The chest x-ray shows hyperinflation of the lungs including prominent pulmonary vascular markings, flattening of the diaphragm, and fluid in the horizontal fissure of the right lung.

TTN is a diagnosis of exclusion as it is a benign condition that can have symptoms and signs similar to more serious conditions, such as respiratory distress syndrome. A chest X-ray may show a radiopaque line - fluid - in the horizontal fissure of the right lung, fluid infiltrate throughout alveoli or fluid in individual lung lobes. The lungs may also appear hyperinflated.

Cyanotic heart defect is a group-type of congenital heart defect (CHD) that occurs due to deoxygenated blood bypassing the lungs and entering the systemic circulation or a mixture of oxygenated and unoxygenated blood entering the systemic circulation. It is caused by structural defects of the heart (i.e.: right-to-left, bidirectional shunting, malposition of the great arteries), or any condition which increases pulmonary vascular resistance. The result being the development of collateral circulation.

Neonatal sepsis is a type of neonatal infection and specifically refers to the presence in a newborn baby of a bacterial blood stream infection (BSI) (such as meningitis, pneumonia, pyelonephritis, or gastroenteritis) in the setting of fever. Older textbooks may refer to neonatal sepsis as "sepsis neonatorum". Criteria with regards to hemodynamic compromise or respiratory failure are not useful clinically because these symptoms often do not arise in neonates until death is imminent and unpreventable. Neonatal sepsis is divided into two categories: early-onset sepsis (EOS) and late-onset sepsis (LOS). EOS refers to sepsis presenting in the first 7 days of life (although some refer to EOS as within the first 72 hours of life), with LOS referring to presentation of sepsis after 7 days (or 72 hours, depending on the system used). neonatal sepsis is the single most important cause of neonatal death in hospital as well as community in developing country.

It is difficult to clinically exclude sepsis in newborns less than 90 days old that have fever (defined as a temperature > 38 °C (100.4 °F). Except in the case of obvious acute viral bronchiolitis, the current practice in newborns less than 30 days old is to perform a complete workup including complete blood count with differential, blood culture, urinalysis, urine culture, and cerebrospinal fluid (CSF) studies and CSF culture, admit the newborn to the hospital, and treat empirically for serious bacterial infection for at least 48 hours until cultures are demonstrated to show no growth. Attempts have been made to see whether it is possible to risk stratify newborns in order to decide if a newborn can be safely monitored at home without treatment despite having a fever. One such attempt is the Rochester criteria.

Withdrawal from marijuana can initiate a preterm birth and meconium staining.

Rh disease (also known as rhesus isoimmunisation, Rh (D) disease, rhesus incompatibility, rhesus disease, RhD hemolytic disease of the newborn, rhesus D hemolytic disease of the newborn or RhD HDN) is a type of hemolytic disease of the newborn (HDN). The disease ranges from mild to severe, and typically occurs only in some second or subsequent pregnancies of Rh negative women where the fetus's father is Rh positive, leading to a Rh+ pregnancy. During birth, the mother may be exposed to the infant's blood, and this causes the development of antibodies, which may affect the health of subsequent Rh+ pregnancies. In mild cases, the fetus may have mild anaemia with reticulocytosis. In moderate or severe cases the fetus may have a more marked anaemia and erythroblastosis fetalis (hemolytic disease of the newborn). When the disease is very severe it may cause hydrops fetalis or stillbirth.

Rh disease is generally preventable by treating the mother during pregnancy or soon after delivery with an intramuscular injection of anti-RhD immunoglobulin (Rho(D) immune globulin). The RhD protein is coded by the RHD gene.

Acrocyanosis is characterized by peripheral cyanosis: persistent cyanosis of the hands or of the hands, feet, or face. The extremities often are cold and clammy and may exhibit some swelling (especially in the warmer weather). The palms and soles exhibit a wide range of sweating from moderately moist to profuse, but all peripheral pulses should have normal rate, rhythm, and quality. Exposure to cold temperatures worsens the cyanosis, while it often improves on warming. Aside from the color changes, patients normally are asymptomatic and therefore there is usually no associated pain. The most common sign, discoloration, usually is what prompts patients to seek medical care.

An infant born addicted to amphetamines is more likely to be born prematurely. It may also be small for gestational age. It may show signs of respiratory distress, infection, exaggerated startle reflex, sleep pattern disturbances. After the infant is born it may have poor weight gain, frequent infections, developmental delays and emotional problems.

The primary symptom is yellowish discoloration of the white part of the eyes and skin in a newborn baby. Other symptoms may include excess sleepiness or poor feeding.

A bilirubin level more than 34 μmol/l (2 mg/dL) may be visible. For the feet to be affected level generally must be over 255 μmol/l (15 mg/dL).

According to a study in cyanotic congenital heart disease (CCHD) in Sohag University, Upper Egypt. 50 neonates were diagnosed as suffering from cyanotic congenital heart disease (CCHD), they concluded that cyanotic congenital heart disease (CCHD) frequency was significant (9.5%) with D-TGA being the commonest type. Majority of neonates with Cyanotic congenital heart disease (CCHD) showed survival with suitable management.

Acrocyanosis is diagnosed clinically, based on a medical history and physical examination; laboratory studies or imaging studies are not necessary. The normal peripheral pulses rule out peripheral arterial occlusive disease, where arterial narrowing limits blood flow to the extremities. Pulse oximetry will show a normal oxygen saturation. Unlike the closely related Raynaud's phenomenon, cyanosis is continually persistent. In addition, there is usually no associated trophic skin changes, localized pain, or ulcerations. Capillaroscopy and other laboratory methods may be helpful but only complement clinical diagnosis in unclear cases, especially when they connective tissue disorders may be present.

IRDS begins shortly after birth and is manifest by fast breathing, more than 60 per minute, a fast heart rate, chest wall retractions (recession), expiratory grunting, nasal flaring and blue discoloration of the skin during breathing efforts.

As the disease progresses, the baby may develop ventilatory failure (rising carbon dioxide concentrations in the blood), and prolonged cessations of breathing ("apnea"). Whether treated or not, the clinical course for the acute disease lasts about 2 to 3 days. During the first day the patient worsens and requires more support. During the second day the baby may be remarkably stable on adequate support and resolution is noted during the third day, heralded by a prompt diuresis. Despite huge advances in care, IRDS remains the most common single cause of death in the first month of life in the developed world. Complications include metabolic disorders (acidosis, low blood sugar), patent ductus arteriosus, low blood pressure, chronic lung changes, and bleeding in the brain. The disease is frequently complicated by prematurity and its additional defects in other organ function.

Infant respiratory distress syndrome (IRDS), also called neonatal respiratory distress syndrome (NRDS), respiratory distress syndrome of newborn, or increasingly surfactant deficiency disorder (SDD), and previously called hyaline membrane disease (HMD), is a syndrome in premature infants caused by developmental insufficiency of pulmonary surfactant production and structural immaturity in the lungs. It can also be a consequence of neonatal infection. It can also result from a genetic problem with the production of surfactant associated proteins. IRDS affects about 1% of newborn infants and is the leading cause of death in preterm infants. The incidence decreases with advancing gestational age, from about 50% in babies born at 26–28 weeks, to about 25% at 30–31 weeks. The syndrome is more frequent in infants of diabetic mothers and in the second born of premature twins.

IRDS is distinct from pulmonary hypoplasia, another leading cause of neonatal death that involves respiratory distress.

Neonatal jaundice is a yellowish discoloration of the white part of the eyes and skin in a newborn baby due to high bilirubin levels. Other symptoms may include excess sleepiness or poor feeding. Complications may include seizures, cerebral palsy, or kernicterus.

In many cases there is no specific underlying disorder (physiologic). In other cases it results from red blood cell breakdown, liver disease, infection, hypothyroidism, or metabolic disorders (pathologic). A bilirubin level more than 34 μmol/l (2 mg/dL) may be visible. Concerns, in otherwise healthy babies, occur when levels are greater than 308 μmol/L (18 mg/dL), jaundice is noticed in the first day of life, there is a rapid rise in levels, jaundice lasts more than two weeks, or the baby appears unwell. In those with concerning findings further investigations to determine the underlying cause are recommended.

The need for treatment depends on bilirubin levels, the age of the child, and the underlying cause. Treatments may include more frequent feeding, phototherapy, or exchange transfusions. In those who are born early more aggressive treatment tends to be required. Physiologic jaundice generally lasts less than seven days. The condition affecting over half of babies in the first week of life. Of babies that are born early about 80% are affected.

Hemolytic disease of the newborn, also known as hemolytic disease of the fetus and newborn, HDN, HDFN, or erythroblastosis fetalis, is an alloimmune condition that develops in a fetus, when the IgG molecules (one of the five main types of antibodies) produced by the mother pass through the placenta. Among these antibodies are some which attack antigens on the red blood cells in the fetal circulation, breaking down and destroying the cells (hemolysis). The fetus can develop reticulocytosis and anemia. This fetal disease ranges from mild to very severe, and fetal death from heart failure (hydrops fetalis) can occur. When the disease is moderate or severe, many erythroblasts (immature red blood cells) are present in the fetal blood, and so these forms of the disease can be called "erythroblastosis fetalis" (or "erythroblastosis foetalis").

HDFN represents a breach of immune privilege for the fetus or some other form of impairment of the immune tolerance of pregnancy. Various types of HDFN are classified by which alloantigen provokes the response. In order of incidence, the types include ABO, anti-RhD, anti-RhE, anti-Rhc, anti-Rhe, anti-RhC, multiantigen combinations, and anti-Kell.

Hemolytic disease of the newborn (anti-RhE) is caused by the anti-RhE antibody of the Rh blood group system. The anti-RhE antibody can be naturally occurring, or arise following immune sensitization after a blood transfusion or pregnancy.

The anti-RhE antibody is quite common especially in the Rh genotype CDe/CDe; It usually only causes a mild hemolytic disease, but can cause a severe condition in the newborn. It can occur with other antibodies, usually the anti-Rhc antibody, which can also cause a severe hemolytic disease.

One study done by Moran et al., found that titers are not reliable for anti-E. Their most severe case of hemolytic disease of the newborn occurred with titers 1:2. Moran states that it would be unwise routinely to dismiss anti-E as being of little clinical consequence.

Hemolytic disease of the newborn (anti-Kell) is the second most common cause of severe hemolytic disease of the newborn (HDN) after Rh disease. Anti-Kell is becoming relatively more important as prevention of Rh disease is also becoming more effective.

Hemolytic disease of the newborn (anti-Kell) is caused by a mismatch between the Kell antigens of the mother and fetus. About 91% of the population are Kell negative and about 9% are Kell positive. A fraction of a percentage are homozygous for Kell. Therefore, about 4.5% of babies born to a Kell negative mother are Kell positive.

The disease results when maternal antibodies to Kell are transferred to the fetus across the placental barrier, breaching immune privilege. These antibodies can cause severe anemia by interfering with the early proliferation of red blood cells as well as causing alloimmune hemolysis. Very severe disease can occur as early as 20 weeks gestation. Hydrops fetalis can also occur early. The finding of anti-Kell antibodies in an antenatal screening blood test (indirect Coombs test) is an indication for early referral to a specialist service for assessment, management and treatment.

Sclerema neonatorum is a rare and severe skin condition that is characterized by diffuse hardening of the subcutaneous tissue with minimal inflammation. It usually affects premature, ill newborns. Prognosis is poor.

Minimal inflammation helps distinguish sclerema neonaturum from subcutaneous fat necrosis of the newborn.

In ABO hemolytic disease of the newborn (also known as ABO HDN) maternal IgG antibodies with specificity for the ABO blood group system pass through the placenta to the fetal circulation where they can cause hemolysis of fetal red blood cells which can lead to fetal anemia and HDN. In contrast to Rh disease, about half of the cases of ABO HDN occur in a firstborn baby and ABO HDN does not become more severe after further pregnancies.

The ABO blood group system is the best known surface antigen system, expressed on a wide variety of human cells. For Caucasian populations about one fifth of all pregnancies have ABO incompatibility between the fetus and the mother, but only a very small minority develop symptomatic ABO HDN. The latter typically only occurs in mothers of blood group O, because they can produce enough IgG antibodies to cause hemolysis.

Although very uncommon, cases of ABO HDN have been reported in infants born to mothers with blood groups A and B.

Common symptoms include:

- tachycardia (a heart rate exceeding the normal resting rate)

- respiratory problems

- dyspnea (shortness of breath)

- continuous "machine-like" (also described as "rolling-thunder" and "to-and-fro") heart murmur (usually from aorta to pulmonary artery, with higher flow during systole and lower flow during diastole)

- cardiomegaly (enlarged heart, reflecting ventricular dilation and volume overload)

- left subclavicular thrill

- bounding pulse

- widened pulse pressure

- increased cardiac output

- increased systolic pressure

- poor growth

- differential cyanosis, i.e. cyanosis of the lower extremities but not of the upper body.

Patients typically present in good health, with normal respirations and heart rate. If the PDA is moderate or large, widened pulse pressure and bounding peripheral pulses are frequently present, reflecting increased left ventricular stroke volume and diastolic run-off of blood into the (initially lower-resistance) pulmonary vascular bed. Prominent suprasternal and carotid pulsations may be noted secondary to increased left ventricular stroke volume.

Signs of hemolytic disease of the newborn include a positive direct Coombs test (also called direct agglutination test), elevated cord bilirubin, and hemolytic anemia. It is possible for a newborn with this disease to have neutropenia and neonatal alloimmune thrombocytopenia as well.Hemolysis leads to elevated bilirubin levels. After delivery bilirubin is no longer cleared (via the placenta) from the neonate's blood and the symptoms of jaundice (yellowish skin and yellow discoloration of the whites of the eyes) increase within 24 hours after birth. Like other severe neonatal jaundice, there is the possibility of acute or chronic kernicterus, however the risk of kernicterus is higher because of the rapid destruction of blood cells. It is important to note that isoimmunization is a risk factor for neurotoxicity and lowers the level at which kernicterus can occur. Untreated profound anemia can cause high-output heart failure, with pallor, enlarged liver and/or spleen, generalized swelling, and respiratory distress.

HDN can be the cause of hydrops fetalis, an often-severe form of prenatal heart failure that causes fetal edema.

Patent ductus arteriosus (PDA) is a condition wherein the ductus arteriosus fails to close after birth.

Early symptoms are uncommon, but in the first year of life include increased 'work of breathing' and poor weight gain. An uncorrected PDA may lead to congestive heart failure with increasing age.

The ductus arteriosus is a fetal blood vessel that closes soon after birth. In a PDA, the vessel does not close and remains "patent" (open), resulting in irregular transmission of blood between the aorta and the pulmonary artery. PDA is common in newborns with persistent respiratory problems such as hypoxia, and has a high occurrence in premature newborns. Premature newborns are more likely to be hypoxic and have PDA due to underdevelopment of the heart and lungs.

A PDA allows a portion of the oxygenated blood from the left heart to flow back to the lungs by flowing from the aorta (which has higher pressure) to the pulmonary artery. If this shunt is substantial, the neonate becomes short of breath: the additional fluid returning to the lungs increases lung pressure, which in turn increases the energy required to inflate the lungs. This uses more calories than normal and often interferes with feeding in infancy. This condition, as a constellation of findings, is called congestive heart failure.

In some congenital heart defects (such as in transposition of the great vessels) a PDA may need to remain open, as it is the only way that oxygenated blood can mix with deoxygenated blood. In these cases, prostaglandins are used to keep the DA open until surgical correction of the heart defect is completed.

Transient bullous dermolysis of the newborn (TBDN) is a skin condition that presents in newborns. It is characterized by blister formation secondary to even mild trauma.

It is associated with "COL7A1".