Polyethylene Bag vs Prewarmed Blanket for Preventing Neonatal Hypothermia During Transfer

Effectiveness of the Polyethylene Bag Compared With a Prewarmed Blanket for Preventing Hypothermia During Intrahospital Transfer in Premature Neonates: A Randomized Pilot Clinical Trial

Premature babies can lose body heat quickly after birth, which can lead to serious health problems. This study compared two methods to keep premature babies warm while they were being moved from the delivery room to the neonatal intensive care unit (NICU): wrapping the baby in a plastic bag (polyethylene bag) versus wrapping the baby in a prewarmed blanket, which is the usual method used in many hospitals. Sixty-seven premature babies weighing 2000 grams or less were randomly assigned to receive one of these two methods. The researchers measured the babies' body temperature, heart rate, oxygen levels, and blood sugar at three points: right after birth, during the transfer, and after arriving at the NICU. The goal was to find out whether the plastic bag method was more effective than the blanket method at preventing low body temperature (hypothermia) in these vulnerable babies.

Study Overview

• Status: Completed
• Conditions: Premature Birth; Neonatal; Hypothermia Neonatal
• Intervention / Treatment: Device: Neonatal Polyethylene Bag; Other: Prewarmed Blanket

Detailed Description

Neonatal hypothermia is a major contributor to morbidity and mortality in premature infants, particularly during the period immediately following birth and during intrahospital transfer to the neonatal intensive care unit (NICU). International guidelines, including those from the World Health Organization and the Neonatal Resuscitation Program of the American Academy of Pediatrics, recommend thermal protection strategies such as the use of polyethylene bags or wraps in very low birth weight infants. However, most prior studies evaluating this intervention have not clearly differentiated outcomes by birth weight, and have primarily focused on body temperature as an outcome, with limited evaluation of other physiological parameters such as heart rate, oxygen saturation, and capillary blood glucose.

This randomized, open-label, parallel-group pilot clinical trial was conducted in the obstetric-surgical unit of a public hospital in Querétaro, Mexico. Sixty-seven premature neonates born before 37 weeks of gestation and weighing 2000 grams or less, who required immediate transfer to the NICU, were randomly assigned to an intervention group (n=33), in which a neonatal polyethylene bag was applied immediately after birth and maintained throughout intrahospital transfer, or a control group (n=34), in which the neonate was dried and wrapped in a prewarmed blanket according to standard unit protocol.

Axillary body temperature, heart rate, oxygen saturation, and capillary blood glucose were measured at three time points: within the first minute of life (baseline), during intrahospital transfer, and five minutes after NICU admission. The primary outcome was the frequency of hypothermia, defined as axillary temperature below 36.5°C, at NICU admission. Secondary outcomes included changes in heart rate, oxygen saturation, and capillary blood glucose between baseline and NICU admission.

Statistical analyses included comparison of baseline characteristics between groups, repeated-measures ANOVA to assess temporal variation of physiological parameters, and binary logistic regression and ANCOVA models adjusted for birth weight and gestational age to account for baseline imbalances between groups. This pilot study aims to provide preliminary evidence on the effectiveness and safety of the polyethylene bag intervention to inform the design of future, larger confirmatory trials.

• Study Type: Interventional
• Enrollment (Actual): 67
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Mexico
  • Querétaro, Mexico
    • Hospital de Especialidades del Niño y la Mujer

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Premature neonates born before 37 weeks of gestation
• Birth weight ≤2000 grams
• Born in the obstetric-surgical unit of the participating public hospital and requiring immediate intrahospital transfer to the Neonatal Intensive Care Unit (NICU)
• Written informed consent provided by parents or legal guardians

Exclusion Criteria:

• Major congenital malformations
• Need for immediate resuscitation procedures incompatible with application of the assigned intervention
• Parents or legal guardians unable or unwilling to provide informed consent

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Polyethylene Bag; Premature neonates weighing ≤2000 g assigned to this arm were placed inside a neonatal polyethylene bag (Neohelp®, Vygon, France) immediately after birth, without prior drying, covering the body up to the neck with the integrated head cap adjusted. The bag was maintained throughout intrahospital transfer until NICU admission.	Device: Neonatal Polyethylene Bag; A neonatal polyethylene bag (Neohelp®, Vygon, France) placed around the infant's body immediately after birth, without prior drying, to reduce evaporative and convective heat loss during intrahospital transfer to the neonatal intensive care unit.
Active Comparator: Prewarmed Blanket; Premature neonates weighing ≤2000 g assigned to this arm were dried immediately after birth and wrapped in a prewarmed blanket (37°C), in accordance with the unit's conventional thermal management protocol during intrahospital transfer to the NICU.	Other: Prewarmed Blanket; Standard thermal management consisting of drying the neonate immediately after birth and wrapping in a blanket prewarmed to 37°C, used as the unit's conventional approach during intrahospital transfer to the neonatal intensive care unit.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Frequency of Neonatal Hypothermia at NICU Admission	Proportion of neonates with axillary body temperature below 36.5°C at NICU admission.	At NICU admission, approximately 5 minutes after arrival

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Heart Rate from Baseline to NICU Admission	Difference in heart rate (beats per minute) between baseline measurement (first minute of life) and measurement at NICU admission.	From first minute of life to NICU admission
Change in Oxygen Saturation from Baseline to NICU Admission	Difference in peripheral oxygen saturation (%) between baseline measurement (first minute of life) and measurement at NICU admission.	From first minute of life to NICU admission
Change in Capillary Blood Glucose from Baseline to NICU Admission	Difference in capillary blood glucose level (mg/dL) between baseline measurement (first minute of life) and measurement at NICU admission.	From first minute of life to NICU admission

Collaborators and Investigators

• Sponsor: Mario Adrián Tienda Vázquez

Study record dates

Study Major Dates

• Study Start (Actual): November 25, 2025
• Primary Completion (Actual): February 17, 2026
• Study Completion (Actual): February 17, 2026

Study Registration Dates

• First Submitted: June 16, 2026
• First Submitted That Met QC Criteria: June 16, 2026
• First Posted (Actual): June 22, 2026

Study Record Updates

• Last Update Posted (Actual): June 22, 2026
• Last Update Submitted That Met QC Criteria: June 16, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Thermoregulation; Neonatal Intensive Care; Very Low Birth Weight; Polyethylene Bag; Intrahospital Transfer
• Additional Relevant MeSH Terms: Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Obstetric Labor, Premature; Obstetric Labor Complications; Pregnancy Complications; Premature Birth
• Other Study ID Numbers: COMBIOENF-006-2025-ME

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