1425 Neonatal Complications Following in-Utero Exposure to Intravenous Ritodrine

Abstract

During the management of a 3 kg term black female infant whose chylothorax was diagnosed at 7 days of age, a total of 450 ml of chyle was removed by repeated thoracentesis before spontaneous heal ing occured. The total n mber of lymphocytes removed Y during 18 days was greater than 10 . Monoclonal antibody studies showed 95% of these cells were T-lymphocytes which were functionally immature as evidenced by their non-responsiveness to mitogen. There was no associated peripheral blood lymphopenia. Nevertheless, peripheral T-cells were abnormal as shown by lack of sheep RBC rosette formation and lack of response to mitogens. The thymus which was absent during the 18 days of therapy, reappeared 2 weeks after disappearance of the chylothorax accompanied by normalization of peripheral T-lymphocyte functions.Loss Detroit.Intravenous administration of ritodrine has been shown to prolong pregnancy in selected patients. However the drug has been associated with maternal cardiovascular and mLtabolic derangements. If tocolytic therapy fails and the neonate delivers soon after ritodrine is discontinued significant drug levels could increase neonatal morbidity.he DurDose of this studv was to examine the following neonatal out'combs: Apgar score min. and 5 min., neonatal pH, plasma bicarbonate,hypotension, hypoglycemia, respiratory distress syndrome & neonatal mortality in infants exposed to IV ritodrine within 12 hours of delivery. Fifty-eight neonates delivered within 12 hours of discontinuing intravenous maternal ritodrine were matched for birthweight and gestational age with 58 control infants without ritodrine exposure. The study infants had a mean G+ of 32.8 + 2.8 wks & a mean BW of 1744 + 512 gm. The potentlal effect-of the total ritodrine dose used and the drug discontinuance to delivery intervals (DDDI) on the 8 neonatal outcomes were evaluated The frequencies of maternal medical and obstetric complications were similar in both groups PROM ar4 prolon ed rupt re of membranes >12 hours were moye.co&non, in t JnfroK <o.oo~). of the neonatal morbldlty variables .ammed only yp hypoglycemia occurred more frequently in the ritodrine'exposed neonates as compared to control group. Stepwise discriminant analysis and stepwise multilinear regression failed to reveal an effect of total maternal ritodrine dose, and DDDI on the occurrence of the neonatal morbidity variables. The analysis showed that gestational age was a good predictor of RDS and neonatal death but that ritodrine dose and DDDI did not add significantly to the prediction of any neonatal complications. These findings suggest that ritodrine used per protocol is not associated with a significant increase in neonatal morbidity.