Admission thyroid evaluation in very-low-birth-weight infants: association with death and severe intraventricular hemorrhage.
OBJECTIVE
To determine if thyroxine (T(4)) and thyrotropin (TSH) levels, measured at the time of admission to the neonatal intensive care unit, are associated with the outcomes of death and/or severe intraventricular hemorrhage (IVH).


METHODS
Blood for total T(4) and TSH was obtained upon admission to the neonatal intensive care unit in infants with birthweights less than 1500 g. Infants were followed until hospital discharge. Statistical analysis included one-way analysis of variance, Pearson correlation, and logistic regression. Data are expressed as mean +/- standard deviation (SD).


RESULTS
One hundred twenty-two infants were enrolled. The mean gestational age of the study population was 27 +/- 2.8 weeks. Both T(4) (R = 0.25, p < 0.01) and TSH (R = 0.39, p < 0.01) at the time of admission correlated with gestational age. Infants who died and/or had severe IVH (n = 31) had lower T(4) (5.0 +/- 2.1 vs. 8.4 +/- 4.1 microg/dL, p < 0.01) and lower TSH (5.5 +/- 6.0 vs. 18.1 +/- 18.1 microIU/mL, p = 0.03) at the time of admission compared to infants who survived without severe IVH. After controlling for gestational age, low T(4) remained associated with an increased odds of death and/or severe IVH (odds ratio for every 1 microg/dL decrease in T(4): 1.4, 95% confidence interval 1.1-1.7).


CONCLUSIONS
Our data show that both low total T(4) and TSH, measured at the time of nursery admission, are associated with death and severe intraventricular hemorrhage. Our data suggest that it may be feasible to design a study of early T(4) supplementation to determine potential benefit in infants with the lowest T(4) values rather than treating based on associated factors such as gestational age.
Kantor
Michelle J
MJ
Section of Neonatology, North Shore Medical Center, Miami, Florida, USA.
Leef
Kathleen H
KH
Bartoshesky
Louis
L
Getchell
Jane
J
Paul
David A
DA
D000704:Analysis of Variance; D001724:Birth Weight; D002543:Cerebral Hemorrhage / Q000453:epidemiology* / Q000401:mortality; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight / Q000097:blood / Q000502:physiology*; D015931:Intensive Care, Neonatal / Q000706:statistics & numerical data; D012044:Regression Analysis; D016019:Survival Analysis; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000097:blood*
D013972:Thyrotropin; D013974:Thyroxine