Cool Prime Comparative Effectiveness Study for Mild HIE

To determine effectiveness of therapy to improve neurodevelopmental outcomes in infants with mild HIE. To determine the adverse effects of Therapeutic Hypothermia (TH) in mild HIE on the neonate and his/her family. Determine heterogeneity of the treatment effect across key subgroups obtained in the first 6 hours after birth prior to the decision to initiate therapy.

This study leverages practice variation within and across 15 participating sites to compare the effectiveness of TH versus normothermia for mild HIE on neurodevelopmental outcomes at 2 years of age.After standardizing all aspects of clinical care for mild HIE (except for TH vs. normothermia)we will enroll 460 infants with mild HIE into the longitudinal, observational comparative effectiveness study.The central aim of the comparative longitudinal cohort of mild HIE is (1) to compare the effectiveness of hypothermia to normothermia on neurodevelopmental outcomes at 2 years, (2) determine the adverse effects of TH on the infant and his/her family; and (3) determine the heterogeneity of treatment effects (moderating effect) across mild HIE subgroups as determined by physiological biomarkers obtained during the 6 hours window to initiate hypothermia. The decision to apply TH or normothermia will be entirely determined by practice parameters at each site.

Eligibility Criteria:
Inclusion Criteria:

Infants must meet all 3 inclusion criteria

1. Neonates born at ≥ 35 0/7 weeks
2. Mild Encephalopathy on neonatal neurologic exam within 6 hours after birth: defined as presence of at least 2 signs of mild, moderate, or severe encephalopathy with no more than 2 signs in the moderate or severe category.
3. Perinatal Acidosis based on at least one of the following (A or B):

   1. pH ≤ 7.00 in any cord or first infant gas (arterial, venous, or capillary) within ≤ 60 min OR base deficit ≥ 16 in any cord or first infant gas (arterial, venous or capillary) within ≤ 60 min
   2. If pH is between 7.01 and 7.15, OR base deficit is between 10 and 15.9 mmol/liter, OR blood gas is not available, an acute perinatal event is an additional criteria required (see below definition)

An acute perinatal event is defined by at least one of the following:

1. Apgar score at 10 min ≤ 5
2. Continued need for resuscitation at 10 min (chest compressions, bag mask ventilation, or positive pressure ventilation)
3. Uterine rupture, placental abruption, cord accident (prolapse, rupture, knot or tight nuchal cord)
4. maternal trauma, maternal hemorrhage, or cardiorespiratory arrest
5. fetal exsanguination from either vasa previa or feto-maternal hemorrhage, shoulder dystocia
6. Any evidence suggestive of acute perinatal event.

Infants are still eligible for enrollment in the COOLPRIME study if the cord or infant's first blood gas (arterial, venous, or capillary) is obtained \>60 minutes of life.

Exclusion Criteria:

1. Gestational age at birth \< 35 0/7 weeks
2. Birth weight \< 1800gm
3. Head circumference \<30cm
4. Congenital or chromosomal anomaly associated with abnormal neurodevelopment or death
5. Moderate or Severe HIE of 3 or more moderate or severe abnormalities on COOLPRIME Sarnat exam within 6 hours of life
6. Any seizures within first six hours of life
7. Redirection of care is being considered