Effect of Hindmilk on Growth Velocity of Very Preterm Infants
Effect of Hindmilk on Growth Velocity of Very Preterm Infants
Research question: Does feeding hindmilk improve weight gain in very preterm infants with
 poor growth velocity?

 Hypothesis: In very preterm infants (born less than 32 weeks gestation) with poor postnatal
 growth velocity (<15 g/kg/day), feeding hindmilk would improve average weight gain by at
 least 4 g/kg per day.

 Study design: This will be a prospective cohort study in very preterm infants admitted to the
 Neonatal Intensive Care Unit (NICU) at Foothills Medical Centre
Extra-uterine growth restriction (EUGR) is one of the most common findings among very preterm
 infants at discharge from neonatal intensive care units. EUGR is associated with major
 morbidities such as bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP) and
 impaired neurodevelopment. EUGR is caused by slow postnatal growth and largely results from
 energy and protein deficits. These deficits occur despite the current fortifications of human
 milk. Hindmilk, the milk at the end of a breast pumping session, has higher fat and energy
 content compared to the composite milk. Feeding hindmilk can be a natural and innovative way
 to provide additional calories for very preterm infant. Hindmilk is rich in some fatty acids
 that are currently under investigation to prevent BPD and ROP and improve neurodevelopment.
 The aim of this study is to assess growth benefits of feeding hindmilk and to explore whether
 it can improve fatty acids profile in very preterm infants.

 Dietitians (RD) and Lactation Consultant (LC) will screen and identify eligible mother-infant
 pairs. Once mother's consent obtained, LC will hand out the "hindmilk information sheet" and
 teach the mother how to separate her milk. A sample (10 ml) of composite pumped fresh milk
 will be collected and placed in the fridge. These samples will be sent for analysis within 24
 hours of collection to minimize any changes to contents. Samples for Erythrocyte membrane
 fatty acid (FA) profile will be collected on dried blood spot (30-100 µL). These samples will
 be collected within 72 hours of the consent. It will be coordinated with blood tests ordered
 by the clinical team within that period. Dried blood spots are stable in room temperature for
 28 days however we will store them in the -80̊ C freezer within 72 hours of collection.
 Another milk sample, hindmilk this time, will be sent for testing within 24-48 hour of
 starting hindmilk. This is to ensure that assessment of milk contents is performed in the
 same mother's lactation stage. The second dried blood spot will be drawn after 2-4 weeks of
 starting hindmilk. The 2-4 weeks period is to allow timing with other blood work-ups. In
 General, blood glucose is done every 2-3 days in babies with poor growth and growth
 laboratory testing is normally done every 2-3 weeks.

 Data on fluid volumes, feeds, macronutrients intakes and any change in nutrition plan will be
 collected from electronic dietitian's notes. Dietitians will ensure proper and detailed
 documentation of nutritional information. Average weight gain (in gram/kg per day) is
 calculated as mentioned before. Average weight gain will be compared initially between the
 week before and the week after starting hindmilk. The day that hindmilk started will be used
 to identify the start point however it will not be used in either the pre- or the
 post-hindmilk calculation. Clinical team will be encouraged to not order other changes to the
 nutrition plan for the first week after starting hindmilk. Daily weight, weekly length and
 head circumference will be collected from the electronic charts. Furthermore, weight, length
 and head circumference at completed gestational week will be used to calculate Z scores using
 Fenton Z scores calculator.

 Data on maternal and neonatal characteristics will be collected from their electronic and
 physical charts. Composite milk, foremilk and hindmilk volumes will be collected from the
 collection sheet that has been already used in our NICU.
Inclusion Criteria:

 -  Very preterm infant ( <32 weeks at birth)

 -  On full enteral feeds for more than 2 weeks (full feed is defined at the time of
 reaching 120 ml/kg/day with no parenteral nutrition used)

 -  Poor weight gain (<15 g/kg per day) despite optimization of energy and protein intakes
 by RDs (calories intake: 125-135 Kcal/kg per day and protein: 4-4.5 g/kg per day)

 -  Mothers have enough milk supply (>150% of infant's daily needs)

 Exclusion Criteria

 -  Congenital anomalies

 -  Small for gestational age infants (< 10th percentile) at birth