Plasma vitamin A levels in the very low birthweight infant--relationship to respiratory outcome.
OBJECTIVE
To examine the association between plasma vitamin A levels and outcome measures in very low birthweight (VLBW) infants, including meta-analysis of all observational studies.


METHODS
A prospective observational longitudinal study of plasma vitamin A levels measured in the cord blood; maternal blood in the first 48 h after delivery; and the infants' blood at 48 h, 7 days and 28 days of age and correlated with antenatal and postnatal events. A meta-analysis of all published observational studies on the association of vitamin A with respiratory outcome in the VLBW infant was undertaken.


METHODS
Fifty-seven infants (88% of all eligible) VLBW infants (< 1500 g) admitted from January through October 1993 to one of two regional neonatal intensive care units in the South Island of New Zealand.


RESULTS
Exposure to antenatal steroids led to a significant increase in infant cord plasma vitamin A levels (P = 0.003), but no influence on infant plasma vitamin A levels at any other time. Exposure to postnatal steroids produced a significant rise in infant plasma vitamin A levels between 7 and 28 days (P = 0.008). After controlling for gestational age, antenatal and postnatal steroid exposure, low vitamin A levels at 48 h increased the risk of developing chronic lung disease (odds ratio for 50 microg/l decrease: 2.04, 95% CI 1.19-5.77) and bronchopulmonary dysplasia (odds ratio 1.96, 95% CI 1.14-6.87). On combining our results in meta-analysis with those of other published prospective observational studies, infants with chronic lung disease had lower plasma vitamin A levels at all times.


CONCLUSIONS
Our results support an association between low plasma vitamin A levels and adverse outcome in the VLBW infant.
Inder
T E
TE
Department of Paediatrics, Christchurch Hospital and Clinical School of Medicine, New Zealand.
Graham
P J
PJ
Winterbourn
C C
CC
Austin
N C
NC
Darlow
B A
BA
D002908:Chronic Disease; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight / Q000502:physiology*; D008137:Longitudinal Studies; D008171:Lung Diseases / Q000097:blood*; D008297:Male; D011446:Prospective Studies; D012178:Retinopathy of Prematurity / Q000097:blood; D014801:Vitamin A / Q000097:blood*
D014801:Vitamin A