Renin and Aldosterone Levels in the Preterm Neonate At Risk for Hypertension

Renin and Aldosterone Levels in the Preterm Neonate At Risk for Hypertension (RENAL HIT Study)

The purpose of this study is to find out if mothers with high blood pressure (Hypertension) and/or diabetes have babies with high levels of different substances (that help to regulate blood pressure, called Renin and Aldosterone) in their blood. The investigators are also trying to determine if these babies have higher blood pressure than those babies born to mothers without high blood pressure or diabetes, during the first year of life.

The investigators will measure your baby's blood pressure once a day for the first 4 days, at 1 week of age, and then once per week until your baby is discharged. The investigators will also measure the blood pressure after discharge at 4 and 10 months of age, either on the day of your baby's follow-up appointment in the Neonatal Follow-up Clinic or at a visit to our Outpatient Nephrology Clinic, both at CHEO.

We will compare two groups of babies born between 26+0 and 34+0 weeks gestation.Group 1 is the babies born to mothers with diabetes and/or high blood pressure, and babies that are small for dates. Group 2 are babies that are 26 to 34 weeks of age, that are born to mothers without these problems.

In the study we will measure the baby's blood pressure once a day for the first 4 days, at 1 week of age, and then once per week until the baby is discharged. We will also measure the blood pressure after discharge at 4 and 10 months of age, either on the day of your baby's follow-up appointment in the Neonatal Follow-up Clinic or at a visit to our Outpatient Nephrology Clinic, both at CHEO.

As blood tests will be done. A small amount of extra blood, 0.75ml - 1.5 ml (about 1/6 -1/3 of a teaspoon, or approximately 1 ml) will be collected for measurement of the blood substances we are studying will be collected when the baby has their regular non-study blood work.

This will be done within six hours of birth and then again at 2-3 weeks of life.

Inclusion Criteria:

1. Infants < 6 hours of age who require NICU admission
2. Infants 26+0 to 34+0 weeks gestation.

Exclusion Criteria:

• Immediate Exclusion from Enrollment

  1. Maternal treatment with drugs known to be teratogenic and cause nephrotoxicity in the fetus (i.e. ACE-Inhibitor).
  2. Infants with known congenital anomalies and/or renal anomalies.
  3. Infants with known chromosomal anomalies.
  4. Infants with severe asphyxia defined as cord pH < 7.0, 5 min Apgar < 3, and urine positive for blood.
  5. Infants with a known or suspected blood loss at birth (ie: uterine rupture, placental abruption, bleeding placenta previa, or post-natal blood loss in the delivery room).
  6. Infants who will not receive follow-up care in Ottawa upon discharge from the NICU (ie: live out of town).