Abstract 1112
Poster Session IV, Tuesday, 5/4 (poster 240)
In prior studies we found that heart rate (HR) and blood pressure (BP) of newborn infants increase during feeding. In this study we tested the hypothesis that the magnitude of these changes would be larger in infants whose mothers reported that there was a history of hypertension (HYP) in their immediate family. Eighty-one healthy, full-term, bottle feeding babies were studied between 18 and 48 hours of age. For 54 of these, their mothers reported no family history of HYP vs 27 mothers who reported there was such a history. Changes in BP and HR (Dinamap) from resting in the crib to being held quietly without a pacifier for 3 min before feeding, and changes from being held to the first 3 min of being fed were computed. There were no significant differences between groups with regard to resting HR or systolic or diastolic BP. Moreover, there were no significant differences between groups in the increases in HR and BP that accompanied the transition from crib to being held. While the groups also had similar increases in systolic BP during feeding, the increases in HR and diastolic BP during feeding were smaller in the HYP group (NO-HYP HR +12.2±1.3bpm vs HYP HR +5.7±1.9, p<.01; NO-HYP DIA-BP +3.5±0.8 vs HYP DIA-BP -.04±1.1, p<.01). These results do not support our hypothesis of greater reactivity in the HYP group. In contrast, they suggest that a family history of HYP may be linked to diminished reactivity to feeding and that this effect can be detected within the first few hours of life. Supported by a research grant from NICHD: RO3-HD35567.
