The skin barrier lipids will be lower in premature infants than in full term infants and will become normal over 3-4 months after birth. The higher skin pH in premature infants will be related to an altered lipid composition which will change as the skin acidifies.

Premature infants have a poor epidermal barrier with few cornified layers, putting them at significant risk for increased permeability to external agents, skin compromise, high water loss and infection. While the skin develops rapidly after birth upon exposure to the dry environment, the ontogeny of the skin maturation and the time to a fully functional and protective stratum corneum (SC) barrier is largely unknown. The impact of a poor skin barrier on nosocomial infections and the morbidity associated with prematurity is not well defined. The purpose is to evaluate skin barrier maturation in premature infants compared to full term infants. The skin barrier lipids will be lower in premature infants than in full term infants and will become normal over 3-4 months after birth. The higher skin surface acidity in premature infants will be related to an altered lipid composition which will change as the skin acidifies.

Full thickness skin samples will be collected from premature and full term infants during the time of medically necessary surgical procedures for genomic/transcriptomics analyses. The gene profiles will be compared to the corresponding biomarker profiles to determine the relationship between genes and gene expression products, i.e., biomarkers. The genomic/transcriptomics, biomarker, instrumental and clinical assessments will be examined for relationships and compared between premature and full term cohorts.

Inclusion Criteria:

(1) Premature infants of gestational ages 24 to 36.9 weeks or healthy full term infants of gestational age ≥ 37 weeks (2) Premature infants who are patients in the Neonatal Intensive Care Unit of University Hospital (3) Healthy full term infants (who were born at University Hospital (4) Full term infants (≥ 37 weeks gestational age) who were transported to Cincinnati Children's Hospital Medical Center for care after birth (4) Free of congenital conditions known to affect the skin such as epidermolysis bullosa, ichthyosis, trisomy 2 (5) Free of skin infections such as herpes simplex (6) Sufficiently medically stable such that study procedures can be tolerated (7) Parent/guardian willing to provide written informed consent for participation

Direct admit surgical subjects

Inclusion Criteria:

1. Premature infants of gestational ages 24 to 36.9 weeks
2. Full term infants ≥ 37 weeks gestational age

(2) Infant admitted directly to the Neonatal Intensive Care Unit of Cincinnati Childrens for surgical procedures after delivery (3) Free of congenital conditions known to affect the skin such as epidermolysis bullosa, ichthyosis and trisomy 21 (5) Free of skin infections such as herpes simplex (4) Sufficiently medically stable such that study procedures can be tolerated (5) Parent/guardian willing to provide written informed consent for participation

Exclusion Criteria:

1. Gestational age < 24 weeks
2. Have congenital conditions that affect the skin such as epidermolysis bullosa, ichthyosis, trisomy 21
3. Have a skin infection such as herpes simplex
4. Judged to be medically unstable such that study procedures cannot be tolerated
5. Parent/guardian unwilling to provide written informed consent for participation.

Direct admit surgical subjects

Exclusion Criteria:

1. Infants ≥ 43 weeks gestational age
2. Have congenital conditions known to affect the skin such as epidermolysis bullosa, ichthyosis, trisomy 21
3. Have a skin infection such as herpes simplex

Adult subject controls:

Inclusion Criteria:

1. Parent of an infant enrolled in the study
2. Free from skin irritation, rash, scars, wounds or other skin damage in an area of at least 200 cm2 on one volar forearm
3. Able to come to the infant's hospital for study measurements on one day when infant measurements are made
4. Willing to provide written informed consent for participation

Exclusion Criteria:

(1) Not a parent of an infant enrolled in the study (2) Have skin irritation, rash, scars, wounds or other skin damage in an area of at least 200 cm2 on one volar forearm (3) Unable to come to the infant's hospital for study measurements on one day when infant measurements are made (4) Unwilling to provide written informed consent for participation

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Infants and parents of infants who are patients at Cincinnati Children's Hospital Medical Center Neonatal Intensive Care Units including premature and full-term infants