Decreased respiratory compliance in infants less than or equal to 32 weeks' gestation, delivered more than 7 days after antenatal steroid therapy.
OBJECTIVE
Our objective was to compare the pulmonary function (respiratory compliance) of infants who were < or = 32 weeks' gestation and delivered > 7 days after a single course of antenatal steroids versus infants who were delivered 1 to 7 days after a single course of antenatal steroids.


METHODS
A prospective cohort study of respiratory system compliance was conducted of infants < or = 32 weeks' gestation within 72 hours of life and before surfactant therapy if needed. The study (remote) group was composed of infants who were treated with antenatal steroids > 7 days before delivery and the comparison group (ideal group) of matched infants who were treated with antenatal steroids 1 to 7 days before delivery. Respiratory system compliance was measured with the single-breath occlusion technique.


RESULTS
Twenty-eight remotely treated infants and 28 ideally treated infants were studied. The remote group had a significantly lower respiratory system compliance per kilogram and total respiratory system compliance when compared with the ideal antenatal steroids group. Within the remote group, infants who received antenatal steroids 8 to 14 days (n = 10) before delivery had a significantly higher respiratory system compliance and a trend to less surfactant need (10% vs 33%) as compared with infants who received antenatal steroids > 14 days (n = 18) before delivery.


CONCLUSIONS
Infants who were < or = 32 weeks' gestation and remotely treated with antenatal steroids (average 21 days) had a significantly lower respiratory compliance compared with matched infants who were ideally treated with antenatal steroids. We speculate that the lower respiratory system compliance may reflect the dissipation of beneficial effects of antenatal steroids on pulmonary function when delivery occurs > 7 days after therapy and particularly when therapy is > 14 days before delivery.
McEvoy
Cindy
C
Department of Pediatrics, Oregon Health & Science University, 707 SW Gaines Rd (CDRC-P), Portland, OR 97239, USA. mcevoyc@ohsu.edu
Schilling
Diane
D
Spitale
Patricia
P
Peters
Dawn
D
O'Malley
Jean
J
Durand
Manuel
M
D000328:Adult; D000403:Airway Resistance; D001623:Betamethasone / Q000008:administration & dosage*; D001724:Birth Weight; D005260:Female; D046128:Fetal Therapies; D005865:Gestational Age; D005938:Glucocorticoids / Q000008:administration & dosage*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D007273:Injections, Intramuscular; D008168:Lung / Q000187:drug effects / Q000196:embryology; D008170:Lung Compliance / Q000187:drug effects*; D008297:Male; D011247:Pregnancy; D011663:Pulmonary Surfactants / Q000627:therapeutic use; D012127:Respiratory Distress Syndrome, Newborn / Q000188:drug therapy / Q000517:prevention & control; D015656:Respiratory Mechanics / Q000187:drug effects
D005938:Glucocorticoids; D011663:Pulmonary Surfactants; D001623:Betamethasone