Maternal Oxygen Administration for Fetal Distress II

Study Overview
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Brief Summary
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Supplementary oxygen is routinely administered to patients, even those with adequate oxygen saturations, in the belief that it increases oxygen delivery. However, oxygen delivery depends not just on arterial oxygen content but also on perfusion. Maternal oxygen administration has been used in an attempt to lessen fetal distress by increasing the available oxygen from the mother. However, the effect of supplemental maternal oxygen therapy on fetal acid base status has been debated for more than seven decades. The investigators found the use of 2 L/min maternal oxygen during the second stage of labor did not adversely affect either the umbilical artery pH value or the fetal heart rate (FHR) pattern distribution.

Official Title
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The Effect of Maternal Long Term High Flow Oxygen Administration During Labor on Umbilical Cord Blood Gases

Conditions
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Oxygen Inhalation Therapy, Labour, Fetal Distress

Intervention / Treatment
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* Device: tight-fitting simple facemask


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: at term (>37 weeks, <42 weeks), singleton, cephalic presentation, spontaneous or induced labor, normal labor, category I FHR tracings, 2 to 3 cm of cervical dilation in nulliparity, 1 to 2 cm of cervical dilation in multipara, informed consent. Exclusion Criteria: respiratory or cardiovascular disease, diabetes mellitus or insulin-treated gestational diabetes mellitus, hypertension or preeclampsia, oligohydramnios, fetal growth restriction, placental abruption, cephalopelvic disproportion, meconium-stained amniotic fluid, tachysystole, having received O2, uterine incision (myomectomy or perforation), anemia, fever, chorioamnionitis, tobacco or alcohol use, disorders in oxygen saturations, hypotension, uncomfortable with facemask.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Female

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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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: air, the first and second stage of labor<br>Patients randomized to the group will receive room air. The therapy will continue until after delivery | |
| Experimental: oxygen, the first and second stage of labor<br>Patients randomized to the group will receive oxygen administered by high flow facemask oxygen at 10 L/min oxygen. The therapy will continue until after delivery | Device: tight-fitting simple facemask<br>* Oxygen will be administered by facemask at 10 L/min oxygen. The therapy will continue until after delivery<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cord arterial pH values | Immediately after delivery (within 30-60 seconds of birth), blood gas sample will be obtained. | within 30 to 60 seconds of birth | 
| Cord arterial partial pressure of oxygen | Immediately after delivery (within 30-60 seconds of birth), blood gas sample will be obtained. | within 30 to 60 seconds of birth | 
| Cord arterial partial pressure of carbon dioxide | Immediately after delivery (within 30-60 seconds of birth), blood gas sample will be obtained. | within 30 to 60 seconds of birth | 
| Cord venous pH values | Immediately after delivery (within 30-60 seconds of birth), blood gas sample will be obtained. | within 30 to 60 seconds of birth | 
| Cord venous partial pressure of oxygen | Immediately after delivery (within 30-60 seconds of birth), blood gas sample will be obtained. | within 30 to 60 seconds of birth | 
| Cord venous partial pressure of carbon dioxide | Immediately after delivery (within 30-60 seconds of birth), blood gas sample will be obtained. | within 30 to 60 seconds of birth | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of abnormal fetal heart tracing |  | at 1 minute after birth |