Antenatal steroids to prevent respiratory distress syndrome: multiple gestation as an effect modifier.
BACKGROUND
To determine the effect of antenatal steroids on the incidence of respiratory distress syndrome and the need for surfactant in low-birth-weight infants (501-1500 grams).


METHODS
A 6 year cohort of 946 infants (396 received complete steroids and 550 received no steroids) was studied for the occurrence of respiratory distress syndrome and the need for surfactant following antenatal steroid therapy. A stratified analysis identified confounding baseline characteristics or effect modifiers. The covariates used were multiple birth, maternal race, sex, mode of delivery, Apgar score <7 at 5 minutes, birth weight and gestational age. A multivariate logistic regression model was used to adjust odds ratios simultaneously for all statistically significant covariates.


RESULTS
Multiple gestation and race were effect modifiers. The reduction in RDS was greatest among singleton infants of black mothers with no significant reduction for multiple gestation white infants. The need for surfactant following steroids was reduced only in the group of singletons of other race (not black or white).


CONCLUSIONS
In this retrospective analysis of cohort data collected prospectively antenatal steroid therapy did not reduce the incidence of RDS in multiple gestation white infants.
D001623:Betamethasone / Q000008:administration & dosage*; D015331:Cohort Studies; D015987:Effect Modifier, Epidemiologic; D005260:Female; D005315:Fetal Diseases / Q000188:drug therapy; D005938:Glucocorticoids / Q000008:administration & dosage*; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D016015:Logistic Models; D016017:Odds Ratio; D011247:Pregnancy; D011272:Pregnancy, Multiple; D011663:Pulmonary Surfactants / Q000008:administration & dosage; D044469:Racial Groups; D012127:Respiratory Distress Syndrome, Newborn / Q000517:prevention & control*; D012189:Retrospective Studies