Incubator humidity and temperature control in infants born at 22-23 weeks' gestation

Background: Preterm infants, especially those born at ≤23 gestational weeks (GW), present with extremes in insensible water loss (IWL) and changes in water balance.

Aims: To prevent water loss from the skin and achieve skin maturation without infection, we investigated transepidermal water loss (TEWL), IWL from the skin (IWL-s), and electrolyte balance with differences in high incubator humidity and temperature control from birth to postnatal 1 month in 22-23 GW and 24-25 GW infants.

Study design: Prospective cohort study.

Subjects: Extremely preterm infants born at 22-23 GW (n = 11) and 24-25 GW (n = 11), admitted to the neonatal intensive care unit between September 2018 and October 2019.

Outcome measures: Total fluid intake (TFI), fluid output volume, TEWL, IWL-s, and electrolyte balance were compared between the two groups with controlled incubator humidity and temperature, gradually decreasing the humidity and ambient temperature from 95% to 50% and from 37.0 to 34.0 °C, respectively, while maintaining the central body temperature at 36.5-37.5 °C.

Results: TEWL and IWL-s between the 22-23 and 24-25 GW was not significantly different for infants at postnatal age. No significant difference in electrolyte imbalance was noted between the two groups, within the first 7 days. Differences in TEWL and IWL-s were eliminated with corresponding humidity and temperature adjustments.

Conclusions: Incubator humidity and temperature control should aid management of 22-23 GW infants to reduce IWL, facilitate skin maturation, and prevent infection.