Post-Discharge Growth and Development of Infants Who Received Targeted Fortification in the NICU

Extremely low birth weight (ELBW) infants are at risk for slow growth, metabolic abnormalities, and poor neurodevelopmental outcomes. Postnatal growth standards are based on estimated intrauterine growth from historical cohort studies and post-mortem analyses. Despite current strategies aimed at appropriate nutrition, a large proportion of these infants have postnatal growth failure (anthropometric values \< 10th percentile) reported in the literature as high as 89-99%. More recent data shows lower rates of postnatal growth failure but further improvement is still needed. Adequate growth is key to ensuring improved neurodevelopment and other outcomes.

The investigators are currently evaluating the effects of a high versus standard protein enteral diet on growth and body composition in infants less than or equal to 1000 grams birth weight in the Neonatal Intensive Care Unit. (H-38611). Infants less than or equal to 1000 grams birth weight are provided an enteral diet with a level of protein based on individual caloric and protein analysis of human milk also known as targeted fortification. The standard protein diet provides 3.5-3.8 g/kg/day of protein, while the high protein diet provides 4.2-4.5 g/kg/day.

The investigators have shown that infants who receive this diet achieve growth at targeted standards. As this diet is well tolerated and associated with improved outcomes in our highest risk neonates, it is imperative to evaluate the benefits of a high protein exclusive human milk diet and the possible positive changes in body composition, specifically lean mass, in these infants. Body composition in these infants receiving targeted fortification is being evaluated at 35-36 weeks post menstrual age.

Because these infants are at such high risk for poor growth and neurodevelopment, it is important to investigate the impact of a higher protein exclusive human milk diet on long-term neurodevelopmental outcomes, body composition, and growth at 18-24 months.

The investigators plan to evaluate the effects of a high versus standard protein enteral diet utilizing targeted fortification on neurodevelopmental outcomes, growth, and body composition at 18-24 months in infants with a birth weight of less than or equal to 1000 grams.

Children who have completed a previous study (H-38611) evaluating the effects of a high versus standard protein diet utilizing targeted fortification with human donor milk products on weight, length, and body composition will be recruited for this study.

Infants in the previous study, (H-38611) were either born at Texas Children's Hospital or transferred to Texas Children's Hospital in the first 24 hours of life and admitted to our Neonatal Intensive Care Unit. These infants had a birth weight of less than or equal to 1000 grams and were randomized to receive a standard protein diet (3.5-3.8 grams of protein per kilogram of body weight- the amount of protein recommended for premature babies by the American Academy of Pediatrics ) or a high protein diet (4.2-4.5 grams of protein per kilogram of body weight- the amount of protein recommended for premature babies by the European Society of Paediatric Gastroenterolgy, Hepatology, and Nutrition). Infants in both groups received recommended clinical guidelines for protein.

While the previous study (H-38611) evaluated the effects of a high versus standard protein diet on weight, length and body composition prior to discharge from the Neonatal Intensive Care Unit, this study (H-44733) will assess if the amount of protein in the diet the infant received impacted growth, body composition, and neurodevelopment at 18-24 months of life.

For the study (H-44733), parents of patients who completed H-38611 will be consented prior to discharge from the Neonatal Intensive Care Unit. For patients who completed the previous study (H-38611) and have been discharged, the investigators will contact the parents by telephone. The investigators will mail a consent form to parents interested in having their child complete the follow-up study (H-44733) so they can review the consent form. Then, if they want to participate in the study, they will contact study staff to schedule an appointment. At the beginning of the appointment study staff will obtain informed verbal and written consent in order to conduct study visit.

This study includes an outpatient visit at 18-24 months corrected gestational age. At the visit, the investigators will obtain baseline anthropometric data, interim medical history, demographic and socioeconomic information, and nutrition history of the child since discharge (formula, human milk, vitamins, and medications). A registered dietitian will ask parents questions about the child's current diet.

Next, body composition will be measured by whole body dual energy x-ray absorptiometry or DXA scan. DXA scan is the current gold standard to provide lean and fat body mass and bone mineral content results. DXA is a way to measure bone mineral density, or the amount of calcium and other minerals in the bones.

In addition, a Neurodevelopmental Evaluation as part of standard follow-up for extremely low birth weight infants (The Bayley Scales of Infant and Toddler Development, 3rd Edition) will be completed. The Bayley Scales of Infant and Toddler Development is used mainly to assess the mental and motor development of infants and toddlers, ages 1-42 months. It will be administered by a pediatric developmental physician.

Results of evaluations will be given to parents and recommendations for follow-up will be made by the physician completing the evaluation.

No interventions are part of this protocol.

Eligibility Criteria:
Inclusion Criteria:

* Children born prematurely, with birth weight of less than or equal to 1000 grams
* Born at Texas Children's Hospital or transferred to the Neonatal Intensive Care Unit from another hospital in the first 24 hours of life
* Completed a previous study (H-38611) in which the child received targeted protein fortification with donor human milk products

Exclusion Criteria:

* Infants not previously enrolled in a previous study (H-38611) in the Neonatal Intensive Care Unit at Texas Children's Hospital
* Infants enrolled in but did not complete a previous study (H-38611) in the Neonatal Intensive Care Unit at Texas Children's Hospital