Preterm infant heart rate is lowered after Family Nurture Intervention in the NICU: Evidence in support of autonomic conditioning.

BACKGROUND

Cardiac complications after premature birth are associated with negative long-term consequences to health. The Family Nurture Intervention (FNI) has been designed to support mother-infant parasympathetic calming sessions in the neonatal intensive care unit (NICU). FNI has shown neurodevelopmental and autonomic benefit across infant development.

AIMS: We tested the hypothesis that heart rate (HR) will decrease after FNI over the course of the NICU stay, compared to matched controls.

STUDY

DESIGN

We used a case-matched design. The intervention included on average four ~1-hour facilitated mother-infant 'calming' sessions per week. We collected 24/7 real time heart rate data from a central monitoring system and analyzed data from two time-periods.

SUBJECTS: The intervention group comprised 37 infants born ~30 weeks gestational age (GA) in a level IV NICU, treated with FNI. From the same NICU and time-period, we created a contemporaneous comparison group of 32 infants who were case-matched to each intervention infant for sex, age-at-birth, singleton or twin status, month of admission and length of stay.

OUTCOME MEASURES: Using generalized estimating equation (GEE) modeling, we analyzed 24/7 HR data during a 1-hour period between 4:30 and 5:30 am each day in the NICU, when all infants were least disturbed. Using repeated measures ANOVA, we analyzed 24/7 HR data during a 6-week period starting 1 week prior to the start of FNI and ending 5 weeks after start.

RESULTS

GEE modeling of the 1-hour data from all subjects showed significant lower HR in the FNI group, compared with controls. ANOVA modeling on a subset of subjects over the five-week period showed that FNI infant HR decreased in a dose-response manner relative to SC HR.

CONCLUSION

This study suggests FNI may condition lower infant HR in a dose-response manner during the NICU stay.