Fetal Haemoglobin and Cerebral and Peripheral Oxygenation.

Study Overview
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Brief Summary
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The aim of this study is to investigate the relationship between cerebral and peripheral oxygenation and oxygen extraction, as measured by NIRS (near-infrared spectroscopy ), and the FHbF (fraction of fetal hemoglobin) and absolute HbF (fetal hemoglobin) concentration in postnatal conditions in term and preterm neonates.

Detailed Description
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During gestation the main fetal oxygen carrier is fetal hemoglobin (HbF). HbF exhibits a significantly higher affinity for oxygen when compared to adult hemoglobin (HbA), which makes it more suitable for oxygen extraction at the lower partial oxygen pressures in utero. Although the regulation of HbF expression is determined developmentally, recent studies report a respectable variation in the fraction of HbF in neonates. Such data suggest that the differences in HbF expression could affect end-tissue oxygenation in neonates. The methodology for measuring oxygen saturation and extraction in cerebral and peripheral tissues of neonates using the near-infrared spectroscopy (NIRS) has been well practiced in our study group. However, the method has not yet been used to investigate whether the fraction of fetal hemoglobin (FHbF) plays a significant role in cerebral and peripheral oxygenation in neonates. The aim of this study is to investigate the relationship between cerebral and peripheral oxygenation and oxygen extraction, as measured by NIRS, and the FHbF and absolute HbF concentration in postnatal conditions in term and preterm neonates.

Official Title
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Influence of Fetal Haemoglobin on Cerebral and Peripheral Oxygenation in Term and Preterm Neonates During the First Two Weeks After Birth Measured by Near Infrared Spectroscopy- a Prospective Observational Pilot Study

Conditions
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Preterm Birth, Oxygen Toxicity, Fetal Hemoglobin

Intervention / Treatment
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* Device: Near-infrared spectroscopy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Term and preterm neonates admitted to the neonatal intensive care unit (NICU) Decision to conduct full life support Written informed consent Exclusion Criteria: No decision to conduct full life support No written informed consent Congenital malformations Family history of haemoglobinopathies (e.g. sickle cell anaemia, thalassaemia)

Ages Eligible for Study
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Minimum Age: 2 Days
Maximum Age: 3 Weeks

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Term neonates<br>≥ 37+0 weeks of gestation | Device: Near-infrared spectroscopy<br>* For NIRS measurements the t-NIRS 1 and NIRO 200 NX (Hamamatsu, Japan) will be used. A cerebral sensor will be placed and fixed with a CPAP (Continuous Positive Airway Pressure) cap on the left forehead and a peripheral sensor on the right forearm. Duration of measurement will be two hours.<br>|
| Preterm neonates<br>≤ 36+6 weeks of gestation | Device: Near-infrared spectroscopy<br>* For NIRS measurements the t-NIRS 1 and NIRO 200 NX (Hamamatsu, Japan) will be used. A cerebral sensor will be placed and fixed with a CPAP (Continuous Positive Airway Pressure) cap on the left forehead and a peripheral sensor on the right forearm. Duration of measurement will be two hours.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| FHbF (%) | Fraction of fetal hemoglobin in percentage | First two weeks after birth | 
| HbF (g/dL) | Fetal hemoglobin concentration in g/dL | First two weeks after birth | 
| Change of cTOI | cerebral tissue oxygenation index (cTOI) | at specific time points (2nd-3rd 6th-8th, 12th-14th day after birth) | 
| Change of pTOI | peripheral tissue oxygenation index (pTOI) | at specific time points (2nd-3rd 6th-8th, 12th-14th day after birth) | 
| Change of cFTOE | cerebral fractional tissue oxygen extraction (cFTOE) | at specific time points (2nd-3rd 6th-8th, 12th-14th day after birth) | 
| Change of pFTOE | peripheral fractional tissue oxygen extraction (pFTOE) | at specific time points (2nd-3rd 6th-8th, 12th-14th day after birth) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Fetal hemoglobin, preterm neonate, term neonate, near-infrared spectroscopy, cerebral oxygenation, peripheral oxygenation, fractional tissue oxygen extraction