An interventional study of Normal saline bolus infusion and Continuous normal saline infusion in Category II Fetal Heart Rate Tracing, sponsored by Queen Savang Vadhana Memorial Hospital, Thailand. Completed at 1 site in Thailand. Open to female participants aged 20 Years to 35 Years. Per ClinicalTrials.gov, last updated 2026-08-17.
Sponsored by Queen Savang Vadhana Memorial Hospital, Thailand · Not applicable, Interventional, and Treatment
This randomized trial compared a normal saline bolus regimen with continuous normal saline infusion. The participants were low-risk pregnant women at term with Category II fetal heart rate tracings. Both groups were prescribed 1,000 mL of normal saline through the same volumetric infusion pump. The bolus group received 500 mL at 1,000 mL/h during the first 30 minutes, followed by 150 mL/h. The continuous group received 150 mL/h throughout. The primary outcome was first recovery from Category II to Category I within 30 minutes. Both groups also received standard intrauterine resuscitation. Fetal heart rate tracings were assessed at 30, 60, and 120 minutes.
Intravenous fluid is a component of intrauterine resuscitation for Category II fetal heart rate tracings. No randomized trial had directly compared bolus and continuous intravenous fluid administration.
Both arms were prescribed 1,000 mL of normal saline through a 21-gauge cannula and the same volumetric infusion pump. The bolus group received 500 mL at 1,000 mL/h during the first 30 minutes. The remaining 500 mL was then administered at 150 mL/h. The continuous group received 150 mL/h throughout. Programmed delivery by 30 minutes was approximately 500 mL in the bolus group and 75 mL in the continuous group. Resuscitation continued until the attending declared Category I recovery or until 120 minutes.
Both groups received standard intrauterine resuscitation. This included left lateral positioning, oxytocin discontinuation where applicable, and oxygen at 10 L/min through a face mask.
The primary outcome was first recovery from Category II to Category I within 30 minutes. First Category I recovery was an absorbing endpoint. A later observed Category II classification did not reverse recovered endpoint status. The participant and attending outcome assessor were masked to allocation. Two masked reviewers independently re-adjudicated the fetal heart rate classifications.
A trained operator measured the inferior vena cava collapsibility index and umbilical artery Doppler pulsatility index at baseline and 30 minutes. The primary analysis used Fisher's exact test, risk difference, relative risk, and number needed to treat.
Queen Savang Vadhana Memorial Hospital, Thailand is the lead sponsor of 29 studies on the registry; 15 are open to participants now.
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Participants were prescribed 1,000 mL of normal saline through a 21-gauge cannula and the same volumetric infusion pump. The first 500 mL was administered at 1,000 mL/h during the first 30 minutes. The remaining 500 mL was then administered at 150 mL/h. Resuscitation continued until the attending declared Category I recovery or until 120 minutes.
Drug: Normal saline bolus infusion
Participants were prescribed 1,000 mL of normal saline through a 21-gauge cannula and the same volumetric infusion pump. Normal saline was administered at 150 mL/h throughout. Resuscitation continued until the attending declared Category I recovery or until 120 minutes.
Drug: Continuous normal saline infusion
Participants were prescribed 1,000 mL of normal saline through a 21-gauge cannula and the same volumetric infusion pump. The first 500 mL was administered at 1,000 mL/h during the first 30 minutes. The remaining 500 mL was then administered at 150 mL/h. The intervention continued until the attending declared Category I recovery or until 120 minutes.
Participants were prescribed 1,000 mL of normal saline through a 21-gauge cannula and the same volumetric infusion pump. Normal saline was administered continuously at 150 mL/h throughout. The intervention continued until the attending declared Category I recovery or until 120 minutes.
First recovery from Category II to Category I EFM tracing within 30 minutes
Proportion of participants with first recovery from Category II to Category I electronic fetal monitoring tracing within 30 minutes of intervention initiation, classified using the NICHD three-tier system. First Category I recovery was an absorbing endpoint. A later observed Category II classification did not reverse recovered endpoint status. Non-recovery was persistent Category II or progression to Category III. Classification was performed in real time by the masked attending outcome assessor.
Time frame: 30 minutes
First recovery from Category II to Category I EFM tracing within 60 minutes
Cumulative proportion of participants with first recovery from Category II to Category I electronic fetal monitoring tracing within 60 minutes of intervention initiation, classified using the NICHD three-tier system. First Category I recovery was an absorbing endpoint. A later observed Category II classification did not reverse recovered endpoint status. Non-recovery by 60 minutes was persistent Category II or progression to Category III.
Time frame: 60 minutes
First recovery from Category II to Category I EFM tracing within 120 minutes
Cumulative proportion of participants with first recovery from Category II to Category I electronic fetal monitoring tracing within 120 minutes of intervention initiation, classified using the NICHD three-tier system. First Category I recovery was an absorbing endpoint. A later observed Category II classification did not reverse recovered endpoint status. Non-recovery by 120 minutes was persistent Category II or progression to Category III.
Time frame: 120 minutes
Mode of delivery
Route of delivery classified as vaginal delivery or caesarean section.
Time frame: At delivery
Neonatal Intensive Care Unit (NICU) admission
Proportion of neonates admitted to the neonatal intensive care unit following delivery.
Time frame: Within 24 hours of delivery
Apgar score at 1 minute
Proportion of neonates with 1-minute Apgar score below 7
Time frame: 1 minute after delivery
Apgar score at 5 minutes
Proportion of neonates with 5-minute Apgar score below 7
Time frame: 5 minutes after delivery
Plan to share: Yes — Deidentified individual participant data that underlie the reported results may be available from the corresponding author. Direct identifiers will not be shared. Participant confidentiality and the Thailand Personal Data Protection Act B.E. 2562 (2019) will apply.
Supporting information: Study protocol, Analytic code
No publications or documents are linked to this record.
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Queen Savang Vadhana Memorial Hospital, Thailand