Neonates up to 14 days old with hypoplastic left heart syndrome or other single right ventricular anomalies who have undergone a Norwood procedure and do not meet any of the study exclusion criteria.

• Enrollment is prior to the Norwood surgery and we will follow your child until they are discharged from the hospital following their second stage surgery hospitalization. Your child may have 1 or 2 study visits after discharge from the hospital following their Norwood surgery, depending on when they are discharged. If your child reaches 9 months of age and has not had their second
  stage surgery, their participation in the study will end.
• On post-operative day 1 following the Norwood surgery, your child will be randomized to a study treatment: either 28-days of open-label oxandrolone, or no oxandrolone (standard of care).
• Most study procedures will take place during your child’s Norwood hospitalization.
• If your child is discharged before 28 days, there will be a required in-person visit around day 28 and another in-person visit prior to his/her second stage surgery.
• Study visits may take 1 to 2 hours and will most likely overlap with regular clinic visits.
• We will monitor your child’s growth and feeding history.
• We will collect blood samples from your child.
• Body composition (lean body mass, fat mass) will be assessed by dual energy X-ray absorptiometry (DXA). No sedation or medicines will be used for this test.
• (Optional) A sample of blood will be collected for future research.

Study duration is approximately 4-6 months.

We cannot promise any benefits to your child or others from your taking part in this research. When we finish the study, we hope to know more about growth in children with HLHS and other single RV anomalies. This may help other children born with heart defects in the future. Benefits for providing a blood sample for the optional biobank: There is no known direct benefit from providing a sample for the biobank. However, the sample that you allow your child to give may help researchers to learn more about the link between genetic and other factors and long-term outcomes for children and adults with heart defects and other conditions.

Oxandrolone is generally well tolerated in infants and children. Most of the side effects are rare and typically disappear once the medicine is stopped or the dose is decreased.

Risks and Possible Side Effects of Oxandrolone:

• Virilization: when a girl develops male sex characteristics or a boy has increased male characteristics
• Decreased liver function
• An increase in the amount of bad cholesterol in the blood
• Accelerated bone maturation in children
• Cysts in the liver or spleen; tumors in the liver (have not been reported in children)
• Oxandrolone should not be used with warfarin as it may result in an increased risk of bleeding complications

Other Options:

Participation in research is completely voluntary. You can decide to allow your child to participate or not to participate.

Instead of being in this research study, your child can receive the care that this hospital regularly provides to support the growth of babies with your child’s condition between surgeries. The study doctor and your child’s care team can talk to you more about the standard of care here at this hospital.

You may choose not to allow your child to provide a blood sample for the biobank. Your child can still participate in the Oxandrolone study without providing a sample for the biobank.

There will be no extra costs to you if your child is in this study. If your child is randomized to receive oxandrolone therapy, the medication will be paid for by the study. Your insurance will not be billed for any research-related intervention, tests or measurements such as the DXA. You are responsible for costs related to your baby’s normal medical care, such as your baby’s surgeries, hospital stays, medicines, lab tests, and doctor’s fees.