The Influence of Oxytocin on Intrapartum Fetal Well-being and Delivery Outcomes in Patients Receiving Epidural Analgesia

The Influence of Oxytocin on Intrapartum Fetal Well-being and Delivery Outcomes in Patients Receiving Epidural Analgesia - a Randomized Controlled Trial

The aim of this study is to determine the influence of oxytocin on fetal well-being during labor in patients receiving epidural analgesia (ELA) with the use of cardiotocography (CTG) and doppler ultrasonography.

CTG is a commonly used technique to monitor the fetal heartbeat and contractions of uterus during pregnancy and labor. The maternal-fetal doppler ultrasonography is a non-invasive method used for the pregnancy surveillance.

Various psychological and psychosocial factors impact the perception of labor pain. Its intensity is described differently by each patient - some claim it to be the worst pain that they experienced during their lives. Usually, the labor pain is more severely experienced by the patients giving birth for the first time and those with induced labor.

Nowadays, there are many non-pharmacological (e.g. acupuncture, massage, TENS) and pharmacological (anesthetic gas, opioids, ELA) methods of labor pain management. ELA is a regional anesthesia, in which the anesthetic drug is injected into the epidural space with the aim to block the pain experienced by the patient without impacting patients ability to move or push during labor. The safety of the procedure is well-discussed and documented in Cochrane review from 2018, which shows no adverse impact on the proportions of Caesarean section, long-term backache, or neonatal outcomes. It is considered to be a golden standard for labor pain management.

Oxytocin is a well-known hormone used for the induction of labor and to stimulate the uterine contraction during labor. The impact of oxytocin alone on CTG pattern and maternal-fetal doppler ultrasonography is discussed in the literature. However, the cumulative effect of ELA and oxytocin remains unclear. Some researchers claim that ELA increases the frequency of uterine contractions and that the additional use of oxytocin leads to higher risk of uterine hyper-stimulation and unreassuring CTG patterns. Whereas the others state that ELA weakens the strength of uterine contractions leading to slow progression of labor and the need to use or increase the use of oxytocin.

There are no data on how the cumulative use of oxytocin and ELA impacts the maternal-fetal flows during labor.

Study Overview

• Status: Enrolling by invitation
• Conditions: Labor Pain; Oxytocin; Labor Epidural Analgesia; Uterine Contraction; Fetal Doppler; Labor Progress

Detailed Description

This is a randomized controlled trial performed at the Clinical Department of Obstetrics and Perinatology at the National Medical Institute of the Ministry of the Interior and Administration. The study will recruit 200 patients in either labor induced by oxytocin or stimulated with oxytocin at 37-42 weeks of gestation, requesting the epidural labor analgesia (ELA) and meeting the inclusion criteria. The patients will be individually randomized to either the study group (n=100), in which the use of oxytocin will be continued after the administration of ELA; or to the control group (n=100), in which the oxytocin will be changed to 0.9% sodium chloride solution after the ELA administration.

The vital signs (blood pressure, saturation, heart rate) and the Doppler velocities in the uterine arteries, umbilical artery and the fetal middle cerebral artery will be measured directly before the administration of ELA and then after 30, 60 and 120 minutes. After 2 hours the patients will be examined to assess the progress of labor. If no progress is detected due to the secondary weakening of uterus contractile function, the oxytocin will be reintroduced in the control group.

Additionally, the velocities in the uterine arteries will be measured during the first day after the delivery.

The labor and neonatal outcomes (e.g mode of the delivery, duration of labor, Apgar score, umbilical artery blood gas analysis) will also be recorded.

• Study Type: Interventional
• Enrollment (Estimated): 200
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• ≥ 18 years old
• singleton pregnancy
• labor induced by oxytocin or stimulated with oxytocin
• signed informed consent form
• cervical dilation ≥ 3cm
• patient requesting and eligible for epidural analgesia
• normal CTG trace for at least 30 minutes before epidural analgesia

Exclusion Criteria:

• less than 18 years old
• preterm delivery
• multiple pregnancy
• fetal malformations
• less than 3cm cervical dilation
• lack of CTG trace for at least 30 minutes before epidural analgesia
• patient not requesting or not eligible for epidural analgesia
• informed consent form not signed
• spontaneous labor without the use of oxytocin

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in CTG pattern	E.g. changes in fetal heart rate, presence of cycling, presence of decelerations, STV value in both arms	During the first two hours after the enrollment
Maternal-Fetal Doppler	The PI values in uterine arteries, umbilical artery and fetal middle cerebral artery	From the enrollment to the first day after the delivery
Labour progression	The change in cervical dilation	The first two hours after the enrollment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Duration of labor	Duration of first and second stages of labor	From the enrollment to two hours after the delivery
Mode of the delivery	Vaginal Birth or Assisted vaginal birth or Caesarean section	At the time of delivery
Umbilical cord blood gasometry	The result of umbilical cord blood gasometry at the delivery	At the delivery
Apgar score	Newborn Apgar score in 1, 3 and 5th minute	At the delivery of newborn
Birth weight of the newborn	Birth weight of the newborn	At the delivery
Presence of Neonatal Complications	hospitalization at neonatal intensive care unit, infections, respiratory or neurological disorders etc.	From the delivery to the hospital discharge of the newborn
Presence of labor complications	Lack of labor progress, Postpartum hemorrhage, Fetal distress, Placental abruption etc.	From enrollment up to two hours after the delivery

Collaborators and Investigators

• Sponsor: Central Clinical Hospital of the Ministry of Internal Affairs and Administration, Warsaw, Poland

Publications and helpful links

General Publications

• Ye Y, Song X, Liu L, Shi SQ, Garfield RE, Zhang G, Liu H. Effects of Patient-Controlled Epidural Analgesia on Uterine Electromyography During Spontaneous Onset of Labor in Term Nulliparous Women. Reprod Sci. 2015 Nov;22(11):1350-7. doi: 10.1177/1933719115578926. Epub 2015 Mar 29.
• Anim-Somuah M, Smyth RM, Cyna AM, Cuthbert A. Epidural versus non-epidural or no analgesia for pain management in labour. Cochrane Database Syst Rev. 2018 May 21;5(5):CD000331. doi: 10.1002/14651858.CD000331.pub4.
• Abrao KC, Francisco RPV, Miyadahira S, Cicarelli DD, Zugaib M. Elevation of uterine basal tone and fetal heart rate abnormalities after labor analgesia: a randomized controlled trial. Obstet Gynecol. 2009 Jan;113(1):41-47. doi: 10.1097/AOG.0b013e31818f5eb6.
• Lurie S, Feinstein M, Heifetz C, Mamet Y. Epidural analgesia for labor pain is not associated with a decreased frequency of uterine activity. Int J Gynaecol Obstet. 1999 May;65(2):125-7. doi: 10.1016/s0020-7292(99)00005-3.

Study record dates

Study Major Dates

• Study Start (Estimated): May 6, 2024
• Primary Completion (Estimated): December 31, 2025
• Study Completion (Estimated): December 31, 2025

Study Registration Dates

• First Submitted: April 30, 2024
• First Submitted That Met QC Criteria: May 3, 2024
• First Posted (Actual): May 8, 2024

Study Record Updates

• Last Update Posted (Actual): May 8, 2024
• Last Update Submitted That Met QC Criteria: May 3, 2024
• Last Verified: April 1, 2024

More Information

Terms related to this study

• Keywords: labor pain; fetal monitoring; labor analgesia; epidural anaesthesia; uterine contractions; fetal well-being; fetal doppler; use of oxytocin; ctg; labor progression
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Labor Pain
• Other Study ID Numbers: KB 26/2024

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Data will be available on reasonable request
• IPD Sharing Time Frame: Study protocol will be available following its publication. The anonymized participant data will become available upon publishing the protocol and the results of the study.
• IPD Sharing Access Criteria: The data will be provided on reasonable request. (contact details: joanna.krol@wum.edu.pl).
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No