Transient tachypnea of the newborn occurs in approximately 1 in 100 preterm infants and 3.6-5.7 per 1000 term infants. It is most common in infants born by Cesarian section without a trial of labor after 35 weeks' gestation. Male infants and infants with an umbilical cord prolapse or perinatal asphyxia are at higher risk. Parental risk factors include use of pain control or anesthesia during labor, asthma, and diabetes.

The rate of BPD varies among institutions, which may reflect neonatal risk factors, care practices (e.g., target levels for acceptable oxygen saturation), and differences in the clinical definitions of BPD.

The mortality rate of meconium-stained infants is considerably higher than that of non-stained infants; meconium aspiration used to account for a significant proportion of neonatal deaths. Residual lung problems are rare but include symptomatic cough, wheezing, and persistent hyperinflation for up to five to ten years. The ultimate prognosis depends on the extent of CNS injury from asphyxia and the presence of associated problems such as pulmonary hypertension. Fifty percent of newborns affected by meconium aspiration would die fifteen years ago; however, today the percent has dropped to about twenty.

In the United States, intrauterine hypoxia and birth asphyxia were listed together as the tenth leading cause of neonatal death.

IH/BA is also a causitive factor in cardiac and circulatory birth defects the sixth most expensive condition, as well as premature birth and low birth weight the second most expensive and it is one of the contributing factors to infant respiratory distress syndrome (RDS) also known as hyaline membrane disease, the most expensive medical condition to treat and the number one cause of infant mortality.

Due to the higher incidence of TTN in newborns delivered by caesarean section, it has been postulated that TTN could result from a delayed absorption of fetal lung fluid from the pulmonary lymphatic system. The increased fluid in the lungs leads to increased airway resistance and reduced lung compliance. It is thought this could be from lower levels of circulating catecholamines after a caesarean section, which are believed to be necessary to alter the function of the ENaC channel to absorb excess fluid from the lungs. Pulmonary immaturity has also been proposed as a causative factor. Levels of phosphatidylglycerol (an indicator of lung maturity) were found to be negative in certain newborns

Mild surfactant deficiency has also been suggested as a causative factor.

In a study conducted between 1995 and 2002, MAS occurred in 1,061 of 2,490,862 live births, reflecting an incidence of 0.43 of 1,000. MAS requiring intubation occurs at higher rates in pregnancies beyond 40 weeks. 34% of all MAS cases born after 40 weeks required intubation compared to 16% prior to 40 weeks.

VALI is most common in patients receiving mechanical ventilation for acute lung injury or acute respiratory distress syndrome (ALI/ARDS).

Possible reasons for predisposition to VALI include:

- An injured lung may be at risk for further injury

- Cyclic atelectasis is particularly common in an injured lung

The most common cause is post-surgical atelectasis, characterized by splinting, i.e. restricted breathing after abdominal surgery.

Another common cause is pulmonary tuberculosis. Smokers and the elderly are also at an increased risk. Outside of this context, atelectasis implies some blockage of a bronchiole or bronchus, which can be within the airway (foreign body, mucus plug), from the wall (tumor, usually squamous cell carcinoma) or compressing from the outside (tumor, lymph node, tubercle). Another cause is poor surfactant spreading during inspiration, causing the surface tension to be at its highest which tends to collapse smaller alveoli. Atelectasis may also occur during suction, as along with sputum, air is withdrawn from the lungs. There are several types of atelectasis according to their underlying mechanisms or the distribution of alveolar collapse; resorption, compression, microatelectasis and contraction atelectasis.

Prolonged high oxygen delivery in premature infants causes necrotizing bronchiolitis and alveolar septal injury, with inflammation and scarring. This results in hypoxemia. Today, with the advent of surfactant therapy and high frequency ventilation and oxygen supplementation, infants with BPD experience much milder injury without necrotizing bronchiolitis or alveolar septal fibrosis. Instead, there are usually uniformly dilated acini with thin alveolar septa and little or no interstitial fibrosis. It develops most commonly in the first 4 weeks after birth.

24 percent of all patients mechanically ventilated will develop VALI for reasons other than ALI or ARDS. The incidence is probably higher among patients who already have ALI/ARDS, but estimates vary widely. The variable estimates reflect the difficulty in distinguishing VALI from progressive ALI/ARDS.

Baylor College of Medicine in Houston, Texas has conducted ACD research since 2001.

The atmosphere is composed of 78% nitrogen and 21% oxygen. Since oxygen is exchanged at the alveoli-capillary membrane, nitrogen is a major component for the alveoli's state of inflation. If a large volume of nitrogen in the lungs is replaced with oxygen, the oxygen may subsequently be absorbed into the blood, reducing the volume of the alveoli, resulting in a form of alveolar collapse known as absorption atelectasis.

Fetal mortality refers to stillbirths or fetal death. It encompasses any death of a fetus after 20 weeks of gestation or 500 gm. In some definitions of the PNM early fetal mortality (week 20-27 gestation) is not included, and the PNM may only include late fetal death and neonatal death. Fetal death can also be divided into death prior to labor, antenatal (antepartum) death, and death during labor, intranatal (intrapartum) death.

Several patients have survived with atypical or “patchy ACDMPV” long enough to receive lung transplants. According to a 2013 case series conducted by St. Louis Children’s Hospital, four ACDMPV patients (ages 4 months, 5 months, 9 months and 20 months of age at time of transplant) with atypical presentations of ACDMPV each underwent a successful bilateral lung transplantation (BLT). As stated in the case study, “If they survive to BLT, patients with ACDMPV can have successful outcomes” and the ACDMPV patients “are alive at last follow-up at 1, 8, 9 and 12 years of age” (as of May 2013).

According to the St. Louis Children's Hospital (the Level I pediatric trauma center and pediatric teaching hospital for the Washington University School of Medicine), which is noted worldwide for its record in pediatric pulmonary transplantation, a type of artificial lung device, the Quadrox, was used after ECMO as a bridge to a dual lung transplant in ten-month-old Eleni Scott of the St. Louis suburb of Florissant, Missouri, who after transplantation returned to her home. Doctors have said it is too early to presume it will continue to work here or work in other pediatric patients as an experiment, much less a successful, curative standard therapy, but the infant has survived thus far, meaning that there might be hope for sufferers of this rare condition. For more information, please see the link to the news release.

Asbestos can cause lung cancer that is identical to lung cancer from other causes. Exposure to asbestos is associated with all major histological types of lung carcinoma (adenocarcinoma, squamous cell carcinoma, large-cell carcinoma and small-cell carcinoma). The latency period between exposure and development of lung cancer is 20 to 30 years. It is estimated that 3%-8% of all lung cancers are related to asbestos. The risk of developing lung cancer depends on the level, duration, and frequency of asbestos exposure (cumulative exposure). Smoking and individual susceptibility are other contributing factors towards lung cancer. Smokers who have been exposed to asbestos are at far greater risk of lung cancer. Smoking and asbestos exposure have a multiplicative (synergistic) effect on the risk of lung cancer. Symptoms include chronic cough, chest pain, breathlessness, haemoptysis (coughing up blood), wheezing or hoarseness of the voice, weight loss and fatigue. Treatment involves surgical removal of the cancer, chemotherapy, radiotherapy, or a combination of these (multimodality treatment). Prognosis is generally poor unless the cancer is detected in its early stages. Out of all patients diagnosed with lung cancer, only 15% survive for five years after diagnosis.

A 2008 bulletin from the World Health Organization estimates that 900,000 total infants die each year from birth asphyxia, making it a leading cause of death for newborns.

In the United States, intrauterine hypoxia and birth asphyxia was listed as the tenth leading cause of neonatal death.

Preterm birth is the most common cause of perinatal mortality, causing almost 30 percent of neonatal deaths. Infant respiratory distress syndrome, in turn, is the leading cause of death in preterm infants, affecting about 1% of newborn infants. Birth defects cause about 21 percent of neonatal death.

Alveolar lung diseases, are a group of diseases that mainly affect the alveoli of the lungs.

Alveolar lung disease may be divided into acute or chronic. Causes of acute alveolar lung disease include pulmonary edema (cardiogenic or neurogenic), pneumonia (bacterial or viral), pulmonary embolism, systemic lupus erythematosus, bleeding in the lungs (e.g., Goodpasture syndrome), idiopathic pulmonary hemosiderosis, and granulomatosis with polyangiitis.

Chronic alveolar lung disease can be caused by pulmonary alveolar proteinosis, alveolar cell carcinoma, mineral oil pneumonia, sarcoidosis (alveolar form), lymphoma, tuberculosis, metastases, or desquamative interstitial pneumonia.

Perinatal asphyxia is the medical condition resulting from deprivation of oxygen (hypoxia) to a newborn infant long enough to cause apparent harm. It results most commonly from a drop in maternal blood pressure or interference during delivery with blood flow to the infant's brain. This can occur as a result of inadequate circulation or perfusion, impaired respiratory effort, or inadequate ventilation. 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.

Based on recent (2005) US NCHS data, the rate of multiple births is now approximately 3.4% (4,138,349 total births, of which 139,816 were twins or higher-order multiple births).

The majority of identical twins share a common (monochorionic) placenta, and of these approximately 15% go on to develop TTTS.

By extrapolating the number of expected identical twins (about one-third) from annual multiple births, and the number of twins with monochorionic placentae (about two-thirds), and from these the number thought to develop TTTS (about 15%), there are at least 4,500 TTTS cases per year in the U.S. alone: 139,816 X .33 X .66 X .15 = 4,568 cases of TTTS per year in U.S. (involving more than 9,000 babies.)

Since spontaneous pregnancy losses and terminations that occur prior to 20 weeks go uncounted by the C.D.C., this estimate of TTTS cases may be very conservative.

Although infertility treatments have increased the rate of multiple birth, they have not appreciably diluted the expected incidence of identical twins. Studies show a higher rate of identical twins (up to 20 times with IVF) using these treatments versus spontaneous pregnancy rates.

One Australian study, however, noted an occurrence of only 1 in 4,170 pregnancies or 1 in 58 twin gestations. This distinction could be partly explained by the "hidden mortality" associated with MC multifetal pregnancies—instances lost due to premature rupture of membrane (PROM) or intrauterine fetal demise before a thorough diagnosis of TTTS can be made.

A kitten that has difficulty in breathing is very likely also to suffer from colic (which can cause weight loss in the early development of a normal kitten), and a very small daily (or twice daily) dose of liquid paraffin (one or two drops placed on the tongue of the kitten, or 0.1 ml) should help to alleviate this problem. FCKS kittens who do not maintain weight are usually among the group which die, but many of them may simply be unable to feed properly due to colic, becoming increasingly weak and lethargic, and fading due to malnutrition as much as to the thoracic problems.

Colic has many causes, but in a kitten with respiratory difficulty it is possible that a malfunction during the breathing process leads the kitten to swallow air instead of taking it into its lungs. The GI tract fills with air while the lungs do not receive a proper air supply, preventing them from inflating fully. Pressure from the stomach exacerbates the condition. Treating for colic with liquid paraffin seems to shorten recovery time from 4–10 weeks to a matter of days.

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.

Rare cases of BOOP have induced with lobar cicatricial atelectasis.