The Impact of Warming on Term NICU Admission Rates in Women Undergoing Scheduled Cesarean Delivery

Monday, 9 November 2015

Melanie L. Chichester, BSN, RNC-OB, CPLC
Labor & Delivery, Christiana Care Health System, Newark, DE, USA
Lynn Elizabeth Bayne, PhD, MSN, BSN, NNP-BC
Christiana Care, Newark, DE, USA
Matthew Hoffman, MPH, MD
Dept of OB/GYN, Christiana Care, Newark, DE, USA


In 2011, a new "bundle" of care, multiple changes in practice instituted together, was developed to produce an improved outcome in preterm neonatal hypothermia, as cold infants are at increased risk of morbidity and mortality. This included the pediatric caregiver receiving the infant at the Operating Room (OR) table with warm blankets, preheating the infant warmer, caregivers warming their hands, use of polyethylene covers for premature infants, and increasing the OR room temperature to 68° F. The results of these changes have markedly reduced preterm neonatal hypothermia. Initially, the goal was to reduce preterm morbidity and mortality; however, we also wished to determine if there was a benefit to term infants. Further, it was anecdotally noted that the mothers may also be receiving a benefit, as there seemed to be fewer women who were hypothermic upon arrival to the OB PACU.

Hypothermia, defined as temperature < 36° C, is an anticipated morbidity during a surgical procedure. It contributes to the risk of coagulopathy, increased surgical blood loss, postoperative wound infection, increases patient discomfort, and delays transfer from the post-anesthesia care unit [PACU]. Women undergoing cesarean delivery have 2 risk factors which increase their chance of emerging from the OR) hypothermic- being female and level of spinal anesthesia. Further, the uterus is also exteriorized for repair after delivery of the baby, exposing internal organs to cold stress. The Obstetric (OB) OR rooms were previously set at approximately 62-65°. As such, there are standards of care initiated to prevent hypothermia: warmed intravenous fluids, warm blankets, warmed oxygen, and warm irrigation fluids. But despite use of these measures, hypothermia and associated shivering have been relatively common occurrences in the OB PACU.


We sought to determine the effect of a bundle of interventions designed to decrease preterm NICU admission hypothermia after cesarean delivery had on term neonate NICU admission after scheduled cesarean delivery. Secondary objectives were to determine if there has been a significant improvement in maternal post-cesarean hypothermia, decreased blood loss, and the incidence of postoperative infection.


We performed a retrospective pre-post analysis assessing the impact of a series of interventions (ambient OR temperature increased from 62-65°F to a standard of 68°F, use of warmed blankets during infant transfer from the OR field to a warmer) designed to decrease preterm hypothermia on term neonates delivered by scheduled cesarean section. Women were included if they were delivering a term (>37 week) singleton non-anomalous fetus by scheduled cesarean section. Our primary outcome was term NICU admission. Univariable analysis was utilized to assess significance.


We identified 1,280 term singleton live births before (Pre-intervention) and 1,411 (Post-intervention) after policy implementation. Neonates who were born in the Post-intervention period tended to be less likely to be admitted to the NICU; though this did not reach statistical significance (7.97% Pre-Intervention vs. 6.17%- P value= 0.068). Maternal and fetal demographic information was unchanged between the two time periods with the exception of a slight increase in maternal BMI (Post intervention 33.82 vs. Pre-Intervention 33.21- P –Value=0.034). Maternal outcomes (hypothermia, blood loss, and postoperative infection) were all non-statistically significant, demonstrating no increase in maternal adverse outcomes for the mothers after implementation.


The use of increased ambient OR room temperature and warmed blankets for transfer from the OR field to a warmer was associated with a trend in decrease NICU admission at term. The mothers did not demonstrate adverse outcomes as a result of the interventions.