The objective of this study is to monitor heart rate variability in preterm infants receiving respiratory support, including conventional mechanical ventilation, during skin-to-skin care. We hypothesize that skin to skin care will be associated with a more mature pattern of parasympathetic activity as measured by various domains of heart rate variability. Specifically, the standard deviation of the normal-to-normal interval (SDNN), the root mean squared of successive differences of normal-to-normal intervals (RMSDD), and the standard deviation of deceleration (SDDec) will decrease in infants that are receiving skin-to-skin care across all types of respiratory support compared to infants who are lying in their isolette.

This will be a prospective crossover study, with each infant serving as their own control. Any infant for whom the parent has consented to participate in the study will have heart rate variability leads applied and be monitored before, during and after a skin-to-skin session with the infant's parent. Due to the nature of the study, blinding is not feasible. Infants will remain on the hospital cardiac monitor during the study to maintain standard of care, and data obtained in this study will not be used for clinical care. All sessions will occur during the infant's NICU admission.

Infants will be screened for eligibility by reviewing the Newborn Intensive Care Unit (NICU) census daily. Consent will be obtained after an infant has delivered. No pregnant women will be approached for consent.

Any infant who has been consented for participation and completes at least 1 skin to skin session will be included in the final study sample. As skin to skin is part of standard of care, and information, aside from gender, will not be obtained from the parent, consent will be obtained for the infant to participate in the study.

This study is observational because there was no randomization (no intervention).

Inclusion Criteria:

• Infants must be less than or equal to 30 weeks gestational age at time of delivery.
• Both inborn and outborn infants are eligible for this study.
• Infants must be less than 6 weeks postnatal age.
• Infants must have had a cranial ultrasound with results showing no intraventricular severe intraventricular hemorrhage (Grade III or IV) [10].
• Infants must require respiratory support at the time of the first session. This will include mechanical ventilation, noninvasive positive pressure ventilation (NIPPV), continuous positive airway pressure (CPAP), high flow nasal cannula (HFNC) or low flow nasal cannula (LFNC).
• Consenting biological or legal adoptive mother of the infant must speak English. If the study is unable to enroll an appropriate number of patients, will consider including non-English speaking patients. However, due to limited resources for this study, we will start with only English-speaking patients. Biological or legal adoptive mother will provide consent for the infant to participate in this study.
• Biological or legal adoptive fathers of the infant are eligible to complete skin to skin sessions with the infant. As we are not collecting any information from the father, and skin to skin is a part of accepted standard of care, consent will not be obtained from the father.
• Infants of employees are eligible to participate. Undue influence or coercion will not be applied to infants of employees and participation or lack thereof will not affect employment status.

Exclusion Criteria:

• Infants who have not received a head ultrasound.
• Infants with grade III or higher intraventricular hemorrhage identified on a head ultrasound.
• Infants on high frequency ventilation, due to the artifact transmitted to ECG.
• Infants with known genetic disorders or known prenatal chromosomal anomalies.
• Infants with one or more major congenital anomaly.
• Infants undergoing active sepsis evaluation or treatment for infection.
• Infants on blood pressure or cardiac medications or infusions including inotropic mediations.
• Mothers (biological or legal adoptive) that are <18 years of age will not be approached for consent.
• Mothers (biological or legal adoptive) who are unable to provide consent due to having a legal representative will not be approached for consent in this study.
• Mothers (biological or legal adoptive) who are prisoners will not be approached for this study as participation requires multiple skin to skin session with the infant

Duration of enrollment (1.5 years)

All infants enrolled had their heart rate variability measured.