Early postnatal hypotension and developmental delay at 24 months of age among extremely low gestational age newborns

Abstract

Objectives: To evaluate in extremely low gestational age newborns, relationships between indicators of hypotension during the first 24 postnatal hours and developmental delay at 24 months of age.

Methods: The 945 infants in this prospective study were born at <28 weeks, were assessed for three indicators of hypotension in the first 24 postnatal hours, and were evaluated with the Bayley Mental Development Index (MDI) and Psychomotor Development Index (PDI) at 24 months corrected age. Indicators of hypotension included: (1) mean arterial pressure in the lowest quartile for gestational age; (2) treatment with a vasopressor; and (3) blood pressure lability, defined as the upper quartile for the difference between the lowest and highest mean arterial pressure. Logistic regression was used to evaluate relationships between hypotension and developmental outcomes, adjusting for potential confounders.

Results: 78% of infants in this cohort received volume expansion or vasopressor; all who received a vasopressor were treated with volume expansion. 26% had an MDI <70 and 32% had a PDI <70. Low MDI and PDI were associated with low gestational age, which in turn, was associated with receipt of vasopressor treatment. Blood pressure in the lowest quartile for gestational age was associated with vasopressor treatment and labile blood pressure. After adjusting for potential confounders, none of the indicators of hypotension were associated with MDI <70 or PDI <70.

Conclusions: In this large cohort of extremely low gestational age newborns, we found little evidence that early postnatal hypotension indicators are associated with developmental delay at 24 months corrected gestational age.

Figure 1

Sample for analyses of hypotension and developmental delay

Figure 2

Lowest MAP (mmHg) in the first 24 hours and Gestational Age (weeks). The bottom of each dark box marks the upper boundary of the lowest quartile, and measures below this boundary are those that were included in our analysis as a hypotension indicator. Asterisks represent outliers.

Figure 3

Odds ratios (and 95% confidence intervals) of the risk of MDI <70 and PDI <70 obtained with logistic regression models that incorporate indicators of hypotension during the first 24 postnatal hours and potential confounders. * Adjustedfor black race, public insurance, primagravida, male sex, gestational age 23–24 weeks, birth weight Z-score < −1, and center ** Adjusted for public insurance, male sex, multiple birth, gestational age 23–24 weeks, birth weight Z-score < −1, and center ^§Lowest ¼ile MAP: lowest MAP recorded in the first 24 hours, in the lowest quartile for gestational age ^¶Vasopressor: treatment for hypotension in the first 24 hours, using any vasopressor (dopamine, dobutamine, epinephrine) ^†Labile MAP: labile blood pressure, defined as the upper quartile of the difference in the lowest and highest MAP MDI Mental Developmental Index PDI Psychomotor Developmental Index