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Published on: February 14, 2021
Preterm birth alters the maturation of baroreflex sensitivity in sleeping infants
Nicole B Witcombe1, Stephanie R Yiallourou, Scott A Sands
1The Ritchie Centre, Monash Institute of Medical Research, Monash University, Melbourne, Victoria, Australia.
Insights
Preterm infants show impaired baroreflex sensitivity (BRS) compared to term infants, especially during quiet sleep. This reduced BRS may increase cardiovascular instability risk in preterm infants during the critical period for sudden infant death syndrome (SIDS).
Area of Science:
- Neonatal physiology
- Cardiovascular regulation
- Sudden Infant Death Syndrome (SIDS) research
Background:
- Impaired blood pressure (BP) control is a potential factor in the higher incidence of sudden infant death syndrome (SIDS) among preterm infants.
- Understanding the development of BP regulation in preterm infants is crucial for identifying risks.
Purpose of the Study:
- To investigate the impact of preterm birth, postnatal age, and sleep state on baroreflex sensitivity (BRS).
- To assess BRS changes in preterm and term infants during the first 6 months of corrected age (CA), a period of heightened SIDS risk.
Main Methods:
- Longitudinal study comparing preterm (n=25) and term (n=31) infants at 2-4 weeks, 2-3 months, and 5-6 months corrected age (CA).
- Daytime polysomnography was used to record BP during quiet sleep (QS) and active sleep (AS) via photoplethysmography.
- Baroreflex sensitivity (BRS) was calculated using cross-spectral analysis.
Main Results:
- Preterm infants did not exhibit the maturational increase in BRS observed in term infants during QS.
- At 2-4 weeks CA during QS, preterm infants had 38% higher BRS than term infants; by 5-6 months CA, BRS was 29% lower (P <.05).
- Preterm infants showed 26% lower BRS in QS compared to AS at 2-3 months CA (P <.05).
Conclusions:
- Preterm birth disrupts the typical maturation of BRS, leading to significantly reduced BRS by 5-6 months CA during QS.
- Lower BRS in QS versus AS at 2-3 months CA in preterm infants may elevate their risk of cardiovascular instability during the peak SIDS incidence period.
Objective:
Impaired blood pressure (BP) control may underpin the increased incidence of the sudden infant death syndrome (SIDS) in preterm infants. This study aimed to examine the effects of preterm birth, postnatal age, and sleep state on BP control by measuring baroreflex sensitivity (BRS) across the first 6 months of term-corrected age (CA), when SIDS risk is greatest.
Methods:
Preterm (n = 25) and term (n = 31) infants were studied longitudinally at 2 to 4 weeks, 2 to 3 months, and 5 to 6 months CA using daytime polysomnography. BP was recorded during quiet (QS) and active (AS) sleep using a photoplethysmographic cuff placed around the infant's wrist (Finometer [FMS, Finapres Medical Systems, Amsterdam, Netherlands]). BRS (milliseconds/mm Hg) was assessed in 1- to 2-minute epochs using cross-spectral analysis.
Results:
In preterm infants, postnatal age had no significant effect on BRS within either QS or AS. This was in contrast to the maturational increase in QS observed in term infants. Compared with term infants, BRS of preterm infants was 38% higher at 2 to 4 weeks CA and 29% lower at 5 to 6 months CA during QS (P <.05). Comparing sleep states, BRS of preterm infants was 26% lower in QS compared with AS at 2 to 3 months CA (P <.05).
Conclusions:
Preterm birth impairs the normal maturational increase in BRS, resulting in a substantial reduction in BRS at 5 to 6 months CA during QS. Lower BRS during QS compared with AS at 2 to 3 months CA may place preterm infants at an increased risk for cardiovascular instability at this age of peak incidence of SIDS.
