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

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

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

Exclusion criteria

• Immediate Exclusion from Enrollment

• Maternal treatment with drugs known to be teratogenic and cause nephrotoxicity in the fetus (i.e. ACE-Inhibitor).
• Infants with known congenital anomalies and/or renal anomalies.
• Infants with known chromosomal anomalies.
• Infants with severe asphyxia defined as cord pH < 7.0, 5 min Apgar < 3, and urine positive for blood.
• 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).
• Infants who will not receive follow-up care in Ottawa upon discharge from the NICU (ie: live out of town).