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Completed

NCT Number: NCT07260240

Recovery Rate From Category II to Category I EFM Tracings in Pregnant Women Receiving Bolus vs Continuous Intravenous Fluid Administration

The goal of this clinical trial is to learn which method of intravenous fluid works better for treating abnormal fetal heart rate patterns during labour in low-risk pregnant women at term. The main question it aims to answer is:

Does a rapid fluid bolus (500 mL given quickly) convert abnormal fetal heart rate tracings to normal within 30 minutes better than slow continuous infusion? Researchers will compare a 500 mL normal saline bolus followed by continuous infusion to continuous infusion alone to see which method improves fetal heart rate patterns faster.

Participants will:

* Be placed in the left lateral position and receive supplemental oxygen by face mask * Have oxytocin stopped if it is being given * Receive normal saline through an IV line - either as a rapid bolus or a slow continuous drip, depending on which group they are assigned to * Have fetal heart rate monitored continuously and assessed at 30, 60, and 120 minutes * Have blood pressure, heart rate, and oxygen levels checked every 15 minutes * Have two ultrasound measurements taken - one of a vein in the abdomen and one of blood flow in the umbilical cord - at the start and at 30 minutes

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Key information

Conditions

Fetal Non Reassuring Fetal Distress Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

20 year–35 year

Sex eligibility

Female

Study type

Interventional

Phase

Not applicable

Primary location

Queen Savang Vadhana Memorial Hospital, Chon Buri, Chon Buri 20110 Recruiting

Si Racha, Changwat Chon Buri, 20110, Thailand

About this study

Intravenous fluid is a key component of intrauterine resuscitation (IUR) for Category II fetal heart rate tracings. However, no randomised trial has compared bolus versus continuous infusion directly.

Intervention :

Both groups receive normal saline from a 1000 mL bag through a 21-gauge cannula. The bolus group receives the first 500 mL as a rapid free-flow infusion (IV bag positioned 110 cm above hand level), followed by the remaining 500 mL at 150 mL/h. The continuous group receives the full 1000 mL at 150 mL/h throughout. All participants also receive standard IUR: left lateral positioning, oxytocin discontinuation where applicable, and supplemental oxygen 10 L/min by face mask.

Outcome Assessment :

The primary outcome (EFM category at 30 minutes) is assessed by the attending physician from a separate room, blinded to group allocation. All EFM tracings are also independently re-adjudicated by two blinded reviewers after delivery.

Physiological Surrogates :

A single trained operator measures inferior vena cava collapsibility index (IVC-CI) by M-mode ultrasound and umbilical artery Doppler pulsatility index (UA PI) at baseline and 30 minutes to assess maternal volume status and fetoplacental resistance.

Statistical Analysis :

The primary analysis uses Fisher's exact test with risk difference, relative risk, and number needed to treat. Cumulative recovery is modelled by discrete-time survival analysis. A pre-specified BMI subgroup analysis and blinded re-adjudication sensitivity analysis are included.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Singleton
  • Thai nationality
  • Gestational Age more than equal 37 Weeks
  • Maternal Age 20-35 Years
  • Cephalic Presentation
  • Electronic Fetal Monitoring (EFM) Category II

Exclusion criteria

  • Maternal underlying diseases : Cardiac disease, Pulmonary disease), Overt DM, Thyroid disease,. etc
  • High risk pregnancy :Pre-eclampsia/Eclampsia), GDM
  • Fetal abnormalities
  • Maternal receiving medications for example : Magnesium sulfate, Pethidine, Opioids
  • Oligohydramnios

Treatment and study plan

500 mL normal saline rapid bolus followed by remaining volume at 150 mL/hour

Drug

Participants receive 500 mL of normal saline as a rapid free-flow intravenous bolus through a 21-gauge cannula, with the IV bag positioned 110 cm above hand level. Once 500 mL is delivered, the remaining 500 mL from the same bag is continued at 150 mL/h. All infusions are continued until delivery or clinical decision to discontinue.

Primary outcomes

  1. Recovery rate from Category II to Category I EFM tracing at 30 minutes

    Time frame: 30 minutes

    Proportion of participants with conversion from Category II to Category I electronic fetal monitoring (EFM) tracing within 30 minutes of intervention initiation, classified using the NICHD three-tier system. Recovery is defined as conversion to Category I. Non-recovery is defined as persistence of Category II or progression to Category III at 30 minutes. Classification is performed by the attending physician by real-time bedside assessment.

Secondary outcomes

  1. Recovery rate from Category II to Category I EFM tracing at 60 minutes

    Time frame: 60 minutes

    Proportion of participants with conversion from Category II to Category I EFM tracing within 60 minutes of intervention initiation, using the same NICHD classification.

    Time Frame:

  2. Recovery rate from Category II to Category I EFM tracing at 120 minutes

    Time frame: 120 minutes

    Proportion of participants with conversion from Category II to Category I EFM tracing within 120 minutes of intervention initiation.

  3. Mode of delivery

    Time frame: At delivery

    Route of delivery classified as vaginal delivery or caesarean section.

  4. Neonatal Intensive Care Unit (NICU) admission

    Time frame: Within 24 hours of delivery

    Proportion of neonates admitted to the neonatal intensive care unit following delivery.

  5. Apgar score at 1 minute

    Time frame: 1 minute after delivery

    Proportion of neonates with 1-minute Apgar score below 7

  6. Apgar score at 5 minutes

    Time frame: 5 minutes after delivery

    Proportion of neonates with 5-minute Apgar score below 7

Sponsors and collaborators

Lead sponsor

Queen Savang Vadhana Memorial Hospital, Thailand

Other

Registry information

Official study title

Recovery Rate From Category II to Category I Electronic Fetal Monitoring (EFM) Tracings in Pregnant Women Receiving Bolus vs Continuous Intravenous Fluid Administration: A Randomized Controlled Trial

Acronym: IUR-RCT

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
Dec 3, 2025
Registry last updated
Jun 10, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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