Cesarean Anesthesia Blood Gas

Effects of Spinal and General Anesthesia Techniques on Maternal-Fetal Blood Gas Gradients and Fetal Carboxyhemoglobin Levels in Cesarean Delivery: A Prospective Observational Cohort Study

This prospective observational cohort study will evaluate maternal and fetal blood gas parameters in women undergoing cesarean delivery under spinal or general anesthesia. Maternal venous blood samples will be obtained immediately before anesthesia induction, and umbilical arterial blood samples will be obtained after delivery and cord clamping. Blood gas parameters, including pH, pCO2, pO2, bicarbonate, base excess, lactate, and fetal carboxyhemoglobin levels, will be compared between the spinal and general anesthesia groups. The study will also evaluate maternal-fetal blood gas gradients, Apgar scores, neonatal intensive care requirements, and the relationship between smoking exposure and fetal carboxyhemoglobin levels.

Study Overview

• Status: Recruiting
• Conditions: Cesarean Delivery
• Intervention / Treatment: Other: Anesthesia Technique

• Study Type: Observational
• Enrollment (Estimated): 134

Contacts and Locations

• Study Contact: Name: Ali KAHVECİOĞLU, MD; Phone Number: +90 5549134317; Email: ali.kahveci92@gmail.com

Study Locations

• Turkey (Türkiye)
  • Istanbul
    • Istanbul, Istanbul, Turkey (Türkiye), 59050
      • Recruiting
      • Bağcılar Training and Research Hospital
      • Contact: Ali KAHVECİOĞLU, MD; Phone Number: +90 5549134317; Email: ali.kahveci92@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

• Sampling Method: Non-Probability Sample

Study Population

Pregnant women undergoing cesarean delivery at the Obstetrics and Gynecology Clinic of Bagcilar Training and Research Hospital. The study is a prospective observational cohort comparing maternal and fetal blood gas parameters and fetal carboxyhemoglobin levels according to the observed anesthesia technique (spinal or general anesthesia).

Description

Inclusion Criteria:

• Adult women undergoing cesarean delivery at the study center.
• Patients receiving spinal or general anesthesia for cesarean delivery.

Exclusion Criteria:

• Patients who are not eligible for participation according to the study protocol.
• Patients in whom spinal anesthesia is converted to general anesthesia because of inadequate spinal block and pain during surgery.

Study Plan

How is the study designed?

Design Details

• Observational Models: COHORT
• Time Perspectives: PROSPECTIVE

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Spinal Anesthesia; Participants undergoing cesarean delivery who receive spinal anesthesia as the anesthesia technique.	Other: Anesthesia Technique; Observed anesthesia technique in women undergoing cesarean delivery. Participants received either spinal anesthesia or general anesthesia as part of routine clinical care; the anesthesia technique was not assigned by the study.
General Anesthesia; Participants undergoing cesarean delivery who receive general anesthesia as the anesthesia technique.	Other: Anesthesia Technique; Observed anesthesia technique in women undergoing cesarean delivery. Participants received either spinal anesthesia or general anesthesia as part of routine clinical care; the anesthesia technique was not assigned by the study.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Umbilical artery pH	Umbilical arterial pH measured after delivery and cord clamping.	Immediately after delivery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maternal venous pH	Maternal venous pH measured immediately before anesthesia induction.	Immediately before anesthesia induction
Umbilical artery pCO2	Umbilical arterial pCO2 measured after delivery and cord clamping.	Immediately after delivery
Umbilical artery pO2	Umbilical arterial pO2 measured after delivery and cord clamping.	Immediately after delivery
Maternal venous pCO2	Maternal venous pCO2 measured immediately before anesthesia induction	Immediately before anesthesia induction
Maternal venous pO2	Maternal venous pO2 measured immediately before anesthesia induction	Immediately before anesthesia induction
Umbilical artery HCO3	Umbilical arterial bicarbonate measured after delivery and cord clamping.	Immediately after delivery
Maternal venous HCO3	Maternal venous bicarbonate measured immediately before anesthesia induction	Immediately before anesthesia induction
Umbilical artery BE	Umbilical arterial base excess measured after delivery and cord clamping	Immediately after delivery
Maternal venous BE	Maternal venous base excess measured immediately before anesthesia induction	Immediately before anesthesia induction
Umbilical artery lactate	Umbilical arterial lactate measured after delivery and cord clamping	Immediately after delivery
Maternal venous lactate	Maternal venous lactate measured immediately before anesthesia induction	Immediately before anesthesia induction
Umbilical artery FCOHb	Fetal carboxyhemoglobin measured in umbilical arterial blood after delivery and cord clamping	Immediately after delivery
Maternal venous FCOHb	Maternal carboxyhemoglobin measured in venous blood immediately before anesthesia induction	Immediately before anesthesia induction
Maternal-fetal pH gradient (ΔpH)	Difference between maternal venous pH and umbilical arterial pH	Immediately after delivery
Maternal-fetal pCO2 gradient (ΔpCO2)	Difference between maternal venous pCO2 and umbilical arterial pCO2	Immediately after delivery
Maternal-fetal lactate gradient (Δlactate)	Difference between maternal venous lactate and umbilical arterial lactate	Immediately after delivery
Apgar score at 1 minute	Apgar score assessed 1 minute after birth using the Apgar score (range, 0-10), with higher scores indicating better neonatal condition.	1 minute after birth
Apgar score at 5 minutes	Apgar score assessed 5 minutes after birth using the Apgar score (range, 0-10), with higher scores indicating better neonatal condition.	5 minutes after birth
Neonatal intensive care unit admission	Requirement for admission to the neonatal intensive care unit after birth	During the immediate neonatal period
Neonatal intubation	Requirement for endotracheal intubation after birth	During the immediate neonatal period
Maternal hypotension requiring treatment	Occurrence of maternal hypotension requiring pharmacologic treatment during cesarean delivery	From anesthesia induction until the end of surgery
Maternal vasopressor requirement	Requirement for vasopressor administration for management of maternal hypotension during cesarean delivery	From anesthesia induction until the end of surgery
Smoking exposure and fetal FCOHb	Association between maternal smoking exposure status and fetal carboxyhemoglobin level measured in umbilical arterial blood	Immediately after delivery

Collaborators and Investigators

• Sponsor: Bagcilar Training and Research Hospital
• Investigators: Principal Investigator: Ali KAHVECİOĞLU, MD, University of Health Sciences, Bağcılar Training and Research Hospital

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: September 28, 2026
• First Submitted That Met QC Criteria: October 1, 2026
• First Posted (Actual): October 6, 2026

Study Record Updates

• Last Update Posted (Actual): October 8, 2026
• Last Update Submitted That Met QC Criteria: October 6, 2026
• Last Verified: October 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: E-10840098-50.04-4657

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No