HIE Neonate Inclusion Criteria:
* Inpatient Neonates diagnosed with HIE
* Pediatric patients who are less than 78 hours of age at the time of enrollment
* Participants whose parent/legal guardian is able to complete consenting process in English
HIE Neonate Exclusion Criteria:
* Participants with prenatally diagnosed or congenital brain and/or eye abnormalities not associated with HIE, including but not limited to microphthalmia, anophthalmia, congenital cataract, eye or eyelid coloboma, congenital glaucoma, CMV retinitis, optic nerve hypoplasia, aniridia, cryptophthalmos, globe abnormalities
* Participants who have a known central nervous system illness other than HIE, including but not limited to congenital brain malformations or congenital hydrocephalus
* Participants whose parent/legal guardian is unable to provide informed consent, including participants who are in foster care, participants within state custody, and participants of minor parents
Waisman, AFCH NBFU, or CERU Clinic HIE Patient Inclusion Criteria:
* Pediatric patients who have a diagnosis of HIE and present to the Newborn Follow Up Clinic
* Pediatric patients who are less than 36 months of age at the time of enrollment
* Participants whose parent/legal guardian is able to complete consenting process in English
Waisman, AFCH NBFU, or CERU Clinic HIE Patient Exclusion Criteria:
* Participants with prenatally diagnosed or congenital brain and/or eye abnormalities not associated with HIE, including but not limited to microphthalmia, anophthalmia, congenital cataract, eye or eyelid coloboma, congenital glaucoma, CMV retinitis, optic nerve hypoplasia, aniridia, cryptophthalmos, globe abnormalities
* Participants who have a known central nervous system illness not associated with HIE and its complications. Complications may include seizures, hydrocephalus, and stroke, which are NOT exclusionary. Examples of exclusionary conditions include but are not limited to traumatic brain injury outside the perinatal period, meningitis, or diagnosis of brain tumor
* Participants whose parent/legal guardian is unable to provide informed consent, including participants who are in foster care, participants within state custody, and participants of minor parents
Well Baby Inclusion Criteria:
* Patient in Meriter's Newborn Nursery
* ≥37 and \<42 weeks gestational age
* 5-minute Apgar Score ≥7
* Occipital Frontal Circumference (OFC) is within average limits for age (\<97th percentile and \>3rd percentile)
Well Baby Exclusion Criteria:
* Admitted to the NICU for any reason
* Known genetic abnormality
* Diagnosed with HIE
* Diagnosed with Hypoglycemia
* Diagnosed with Hyperbilirubinemia requiring phototherapy
* Identified prenatal exposure to substances, including illicit drugs, alcohol, and/or tobacco
* Known or suspected neonatal infection requiring treatment (e.g., antibiotics)
* TORCH infections
* Abnormal newborn hearing screen
* Abnormal toxicology screening
* Identified as large for gestational age (LGA) or small for gestational age (SGA)
* Participants with prenatally diagnosed or congenital eye abnormalities, including but not limited to microphthalmia, anophthalmia, congenital cataract, eye or eyelid coloboma, congenital glaucoma, CMV retinitis, optic nerve hypoplasia, aniridia, cryptophthalmos, globe abnormalities, and nystagmus
* Subjects who have a known central nervous system illness or malformation, including but not limited to congenital brain malformations or congenital hydrocephalus
* Participants whose parent/legal guardian is unable to provide informed consent, including subjects who are in foster care, subjects within state custody, and subjects of minor parents
* The attending medical team does not approve
