Perinatal asphyxia

Perinatal asphyxia (also known as neonatal asphyxia or birth asphyxia) is the medical condition resulting from <a href="/facts/Asphyxia/bahl3DJf">deprivation of oxygen</a> to a newborn infant that lasts long enough during the <a href="/facts/Childbirth/KaWFJ4kG">birth process</a> to cause physical harm, usually to the brain. It remains a serious condition which causes significant mortality and <a href="/facts/Morbidity/55eeQlGL">morbidity</a>. It is also the inability to establish and sustain adequate or spontaneous <a href="/facts/Breathing/92Wov2gk">respiration</a> upon delivery of the newborn, an emergency condition that requires adequate and quick <a href="/facts/Resuscitation/4XVQBKkV">resuscitation</a> measures. Perinatal asphyxia is also an oxygen deficit from the 28th week of <a href="/facts/Gestation/QKgkykw5">gestation</a> to the first seven days following delivery. It is also an <a href="/facts/Insult_(medical)/Gyq3Q5Bl">insult</a> to the <a href="/facts/Fetus/evocHd0Y">fetus</a> or newborn due to lack of oxygen or lack of <a href="/facts/Perfusion/EFVLNUTg">perfusion</a> to various organs and may be associated with a lack of <a href="/facts/Breathing/92Wov2gk">ventilation</a>. In accordance with <a href="/facts/WHO/YNN3bgug">WHO</a>, perinatal asphyxia is characterised by: profound <a href="/facts/Metabolic_acidosis/sSKCKBHA">metabolic acidosis</a>, with a <a href="/facts/Acid%E2%80%93base_homeostasis/y4U6UENE">pH</a> less than 7.20 on <a href="/facts/Umbilical_cord/WIBgdrmF">umbilical cord</a> arterial <a href="/facts/Cord_blood/Nh9ChjmE">blood sample</a>, persistence of an <a href="/facts/Apgar_score/lyqUd92c">Apgar score</a> of 3 at the 5th minute, clinical neurologic sequelae in the immediate neonatal period, or evidence of multiorgan system dysfunction in the immediate neonatal period. Hypoxic damage can occur to most of the infant's organs (<a href="/facts/Heart/fF4KSGdk">heart</a>, <a href="/facts/Lung/gTWXI6Fj">lungs</a>, <a href="/facts/Liver/Rtp4Fk2b">liver</a>, <a href="/facts/Gut_(zoology)/nK2zwqBS">gut</a>, <a href="/facts/Kidneys/HBspPrv9">kidneys</a>), but <a href="/facts/Brain_damage/70hWCEhs">brain damage</a> 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 <a href="/facts/Intellectual_disability/IuuYXdT1">intellectual disability</a>, or physical, such as <a href="/facts/Spasticity/XLnsqIDJ">spasticity</a>.
It results most commonly from <a href="/facts/Antepartum/VpV3S4lu">antepartum</a> causes like a drop in maternal <a href="/facts/Blood_pressure/VtqqSM2J">blood pressure</a> or some other substantial interference with blood flow to the infant's brain during delivery. This can occur due to inadequate <a href="/facts/Circulatory_system/WXwudzzc">circulation</a> 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 <a href="/facts/Hypoxic_ischemic_encephalopathy/rKLaKRC3">hypoxic ischemic encephalopathy</a> or <a href="/facts/Intraventricular_hemorrhage/1NDrD4E4">intraventricular hemorrhage</a>, especially in <a href="/facts/Preterm_birth/szMos8tu">preterm births</a>. An infant with severe perinatal asphyxia usually has poor color (<a href="/facts/Cyanosis/V7ynzIjn">cyanosis</a>), perfusion, responsiveness, muscle tone, and respiratory effort, as reflected in a low 5 minute <a href="/facts/Apgar_score/lyqUd92c">Apgar score</a>. Extreme degrees of asphyxia can cause <a href="/facts/Cardiac_arrest/HIAm9AWX">cardiac arrest</a> and death. If resuscitation is successful, the infant is usually transferred to a <a href="/facts/Neonatal_intensive_care_unit/XvQ9LaM2">neonatal intensive care unit</a>.
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 <a href="/facts/Free_radicals/qFymuVoT">free radicals</a>, which have a role in <a href="/facts/Reperfusion_injury/3MWNux98">reperfusion injury</a> after asphyxia. Research by <a href="/facts/Ola_Didrik_Saugstad/F2Mk6fwL">Ola Didrik Saugstad</a> 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.

Perinatal asphyxia open-in-new

Perinatal asphyxia