Intrauterine hypoxia
Intrauterine hypoxia | |
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placental infarct (left of image), a cause of intrauterine hypoxia. H&E stain. | |
Specialty | Pediatrics |
Intrauterine hypoxia (also known as fetal hypoxia) occurs when the fetus is
Presentation
Maternal Consequences
Complications arising from intrauterine hypoxia are some of most common causes of preeclampsia.[8] Preeclampsia is a hypertensive disorder that occurs during the second trimester (after the 20th week of pregnancy) resulting from a poorly perfused placenta.[9] The World Health Organization estimates that preeclampsia and eclampsia are responsible for about 14% of maternal deaths globally (around 50,000 to 75,000 deaths annually).[10]
During pregnancy, women with preeclampsia faces serious risk of damage to vital organs such as the kidneys, liver, brain, and the blood system. This hypertensive disorder may also cause damage to the placenta leading to issues such as
Cause
Intrauterine hypoxia can be attributed to maternal, placental, or fetal conditions.[12] Kingdom and Kaufmann classifies three categories for the origin of fetal hypoxia: 1) pre-placental (both mother and fetus are hypoxic), 2) utero-placental (mother is normal but placenta and fetus is hypoxic), 3) post-placental (only fetus is hypoxic).[13]
Pre-placental hypoxia is most commonly caused by external hypoxic environments (such as high altitude). It can also be caused by maternal respiratory conditions (such as asthma), cardiovascular conditions (such as heart failure, pulmonary hypertension, and cyanotic heart disease), and hematological conditions (such as anemia).[14] Conditions such as obesity, nutritional deficiencies, infections, chronic inflammations, and stress can also affect the maternal oxygen supply and fetal uptake.[12]
The most preventable cause is maternal smoking.
Utero-placental hypoxia is associated with abnormal placental implantation, impaired vascular remodeling and vascular diseases.[14] It is also associated with pregnancies complicated by gestational hypertension, intrauterine growth restriction, and pre-eclampsia.[25][26]
Post-placental hypoxia is associated with mechanical obstructions of the umbilical cords, reduced uterine artery flow, progressive fetal cardiac failure, and genetic anomalies.[12][14]
The perinatal brain injury occurring as a result of birth asphyxia, manifesting within 48 hours of birth, is a form of hypoxic ischemic encephalopathy.[27]
Diagnosis
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Treatment
Treatment of infants with birth asphyxia by lowering the core body temperature is now known to be an effective therapy to reduce mortality and improve neurological outcome in survivors, and hypothermia therapy for neonatal encephalopathy begun within 6 hours of birth significantly increases the chance of normal survival in affected infants.[28]
There has long been a debate over whether newborn infants with birth asphyxia should be resuscitated with 100% oxygen or normal air.
Underlying etiology of intrauterine hypoxia serves as a potential therapeutic target. If maternal preeclampsia[34] is the underlying cause of fetal growth restriction (FGR) antihypertensive therapy and magnesium sulfate are potential therapies.[12] Antihypertensive treatment is used to reduce blood pressure and prevent pulmonary edema and cerebral hemorrhages. An effective course of antihypertensive treatments should reduce blood pressure to below 160/110 mmHg. Magnesium sulfate acts as a vasodilator, reducing vascular resistance and protect the blood-brain barrier (BBB). The goal of these treatments is to prolong pregnancy and increase fetal survival. Each day gained by treatment in utero increases fetal survival and intact survival by 1%–2% up to 28 weeks gestation.[35]
Prevention
Medical testing and care can be performed in order to prevent intrauterine hypoxia, though can be difficult. These tests don't directly detect hypoxia, but instead detects the general well-being of the baby and ensures that the baby is healthy since hypoxia causes a wide range of responses. These tests can include prenatal testing, such as fetal movement and amniotic fluid levels, Doppler examination, or fetal heart rate.[36] Another risk factor is premature birth in which medical intervention, such as premature birth prevention or C-section delivery, can be used as prevention for intrauterine hypoxia.[37]
Studies have shown a connection between tetrahydrobiopterin (BH4) deficiency and hypoxia-ischemia brain injury, though further studies need to be done.[38] Measuring fetal BH4 levels can be another way to look out for intrauterine hypoxia.[citation needed]
During birth, birth asphyxia can occur in which cardiotocograph can be used to monitor the baby's health during labor.[39]
Epidemiology
In the United States, intrauterine hypoxia and birth asphyxia were listed together as the tenth leading cause of neonatal death.[40]
Society
IH/BA is also a causative 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.[41][42][43]
Most expensive medical condition treated in U.S. hospitals. 4 out of 10 linked to intrauterine hypoxia/birth asphxia | Cost | Hospital Charge |
1. Infant respiratory distress syndrome | $45,542 | $138,224 |
2. Premature birth and low birth weight | $44,490 | $119,389 |
6. Cardiac and circulatory birth defects | $35,960 | $101,412 |
9. Intrauterine hypoxia or birth asphyxia | $27,962 | $74,942 |
Medicolegal
In the United States the National Practitioner Data Bank 2006 Annual Report obstetrics-related cases accounted for 8.7 percent of all 2006 physician Malpractice Payment Reports and had the highest median payment amounts ($333,334).[44]
References
- PMID 34151398.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - S2CID 1170955.
- PMID 12630342.
- S2CID 245156371.
- PMID 9713399.
- PMID 18482625.
- PMID 17056843.
- .
- ^ Publishing, Harvard Health (26 October 2018). "Preeclampsia And Eclampsia". Harvard Health. Retrieved 2020-07-28.
- PMID 25103301.
- PMID 29367581.
- ^ S2CID 28778818.
- PMID 9364596.
- ^ PMID 20981293.
- PMID 24351784.
- ^ PMID 18259022.
- PMID 9618392.
- S2CID 16661101.
- PMID 16369054.
- PMID 7485292.
- PMID 9364596.
- PMID 12533965.
- S2CID 46837857.
- ISBN 978-0-387-98894-8.
- PMID 20981293.
- S2CID 25586771.
- ^ "Hypoxic-Ischemic Encephalopathy: Practice Essentials, Background, Pathophysiology". 2019-11-13.
{{cite journal}}
: Cite journal requires|journal=
(help) - PMID 23007949.
- S2CID 24825982.
- PMID 11385146.
- ^ ILCOR Neonatal Resuscitation Guidelines 2010
- ^ "Norwegian paediatrician honoured by University of Athens". Norway.gr.
- PMID 4606933.
- ^ "Maternal preeclampsia". Mayo Clinic.
- S2CID 25449681.
- S2CID 8301182.
- ^ "Preventing Hypoxic-Ischemic Encephalopathy (HIE)". HIE Help Center. Retrieved 2020-07-28.
- PMID 19798726.
- PMID 17400026.
- ^ "Deaths: Preliminary Data for 2004". National Center for Health Statistics. June 2019.
- PMID 19088083.
- S2CID 27929018.
- ^ "Hyaline Membrane Disease". EMedicine. 27 April 2022.
- ^ "National Practitioner Data Bank 2006 Annual Report" (PDF). Archived from the original (PDF) on 2010-05-27. Retrieved 2010-01-21.
External links
- Zanelli SA (3 April 2021). "Hypoxic-Ischemic Brain Injury in the Newborn". Medscape. WebMD LLC.
- Zanelli SA (3 April 2021). "Hypoxic-Ischemic Encephalopathy". Medscape. WebMD LLC.
- Johnson K. "Clear Criteria for Defining Birth Asphyxia". Medscape. WebMD LLC.