This study aims to determine normative values of oxygen saturation in late preterm infants, and evaluate the frequency of hypoxic events in infants requiring caffeine at discharge and those not requiring it.

Apnea of prematurity is a common morbidity among premature infants. Recent studies suggest an association between apnea and neurodevelopmental impairment. Our objectives are to determine normative values of oxygen saturation in late preterm infants -reference group. In infants born 28-35 weeks requiring caffeine- study group and infants born 28-35 weeks not requiring caffeine-control group we will be evaluating the frequency of hypoxic events. Recruitment time: February 2015 until December 2016.

After consent a pulse oxymeter will be placed on the infant's right wrist. For those infants that will receive caffeine prior to discharge, this medication will be instituted after 12 hours of the initiation of the study and continue for the remaining of the hospitalization. For all other infants, the pulse oxymeter will be done continuously until discharge. After discharge, the recording will be done at home once a week until 46 weeks corrected age in the three groups.

All the data will be reviewed by a blind observer to the groups from which that data comes. The data will be analyzed by a statistician.

Normative values will be developed on the reference group until 46 weeks post conceptional age.

Any medical problems encounter by the patients while on the study or in the following 6 months will be recorded to establish the safety of caffeine use at home and its discontinuation at 44 weeks post conceptional age.

Inclusion Criteria of infants admitted to NICU:

1. Gestational age at birth of < or = 35 weeks
2. Families of infants that live in Calgary
3. Infants discharged home from PLC or South Health Campus (SHC)
4. Decision of treating team to start caffeine
5. No episodes of clinically significant apnea for a period of 3 to 5 days prior to discharge
6. Infant has access to reliable post-discharge follow up

Exclusion Criteria of all infants:

1. Active serious medical conditions other than apnea (Congenital Heart Disease (CHD), Chronic Lung Disease (CLD), symptomatic anemia).
2. Congenital disorders like Trisomies, genetic syndromes, midline defects, metabolic disorders.

Newborn infants admitted at two NICU centers in Calgary born prematurely between 26 weeks and 34 weeks of gestational age.

Newborn infants admitted directly to the normal nursery in those two centers born less than 38 weeks.