Neonatal Warming to Prevent Hypothermia

The trial will be advertised and introduced to patients admitted to the OU Children's Hospital labor and delivery or antepartum units by research nurses. Interested participants will be consented. Researchers are choosing to only include patients undergoing non-emergent cesarean in order to improve their ability to control parameters such as room temperature and labor-related clinical or subclinical maternal infection, which are known confounders. Further, they are limiting their investigation to fetuses 32-36 weeks gestation, since this population represents the largest preterm delivery population. Recruitment and randomization will be stratified by gestational age with an aim to enroll at least 44 pregnancies at 32-34 weeks and 6 days and 20 pregnancies between 35-36 weeks and 6 days. Last, it is impossible to recruit patients outside of the inpatient setting for a study investigating preterm delivery, as such deliveries are rarely predictable in the outpatient setting. There will only be one site for this study, the OU Children's Hospital labor and delivery and antepartum units.

The proposed study is a pragmatic randomized controlled pilot trial of neonatal warming techniques with participants allocated in a 1:1 ratio using a random block allocation table using blocks of size 4 and 6 that are stratified by gestational age ranges of 35-36 weeks and 6 days and 32-34 weeks and 6 days. Since there cannot be a placebo intervention, neither the patient nor the neonatal team will be blinded to the group assignment. The group assignments will be made and coded by a third party at the time of randomization. Patients will be randomized to their respective groups immediately prior to surgery.

The surgical technician will be provided with the necessary neonatal wraps and mattresses in a sterile fashion, and they will ensure these are available on the surgical field once the cesarean has begun. In the intervention group, the thermal mattress will be activated immediately prior to hysterotomy and placed on the sterile field with delivery of the infant directly onto the mattress. The infant will be dried, stimulated and bulb suctioned as deemed necessary per standard of care followed by wrapping. In the non-intervention group, the infant will be delivered onto the sterile field, dried and suctioned as deemed necessary per OU standard. Cord clamping will be delayed for 60 seconds in all infants under the supervision of both the obstetrician and the neonatal resuscitation team. If either team believes delayed cord clamping is no longer considered safe, as is usual protocol, the cord will be clamped and cut and the baby will be handed off to the neonatology team. After the infant is handed to the neonatology team along with all group assignment specific materials (neonatal wrap and thermal mattress, if in the intervention group), neonatal temperature will be assessed immediately upon arrival to the resuscitation warmer using a digital thermometer placed in the axillary space. Infant temperature will be recorded at 1) arrival to the warmer, 2) after the neonatologist deems that in-room resuscitation is complete and 3) at admission to the Neonatal Intensive Care Unit (NICU), Mother Baby Unit (MBU) or Post-Anesthesia Care Unit (PACU) depending on the baby's needs; determined by the resuscitating physicians. These measurements will be recorded by research nurses in a data collection sheet. Further, the research nurse will record the time from delivery to the time it takes for the infant to arrive at the warmer. Upon arrival at the warmer, the mattress and wrap will be removed as neonatal evaluation takes place.

As immediate neonatal temperature is not generally discussed with patients unless there is an issue such as concern for infection, neonatal temperature will not be routinely discussed with all participants. Only if there is concern for neonatal infection or if there is hyperthermia (>37.5 degrees C) will the study results be discussed with the patient.

Inclusion criteria

• Patients who have non-emergent cesarean deliveries (defined as at least 2 hours prior to planned cesarean)
• Gestational age between 32 weeks and 0 days and 36 weeks and 6 days determined per usual clinical parameters

Exclusion criteria

• Fetal anomalies or death
• Maternal diabetes
• Neonates with blistering skin conditions
• Reversed end diastolic umbilical artery flow
• Placental abruption
• Chorioamnionitis
• Monochorionic multifetal pregnancies
• Inability to provide consent
• Provider perception that patient is in significant pain and provider perceived contraindications to delayed cord clamping.