The efficacy of a single course of antenatal steroids beyond seven days

ALAN PEACEMAN, KOMAL BAJAJ, PRAVEEN KUMAR, WILLIAM GROBMAN, Northwestern University, Obstetrics and Gynecology, Chicago, Illinois, Northwestern University, Neonatology, Chicago, Illinois OBJECTIVE: To determine whether the benefits of a single course of antenatal steroid (AS) treatment for neonatal respiratory morbidity diminish beyond seven days from initiating treatment. STUDY DESIGN: A retrospective chart review was performed of deliveries !34 wks gestation where delivery occurred after completing a single course of AS (dexamethasone or betamethasone). Maternal and neonatal charts were reviewed, treatment course was confirmed, and neonatal morbidities were collected. A review of 190 charts provided more than 80% power for demonstrating a 50% reduction in the need for respiratory support (ventilation, CPAP) if delivery occurred within 7 days of treatment. RESULTS: Of 197 infants whose mothers received a full course of AS, 98 delivered within 7 days, and 99 delivered more than 7 days after the initial dose. The two groups were similar in gestational age at delivery (30 wk 0 d vs 30 w 4 d). The groups were also similar in maternal age, race, payor status, type of steroid given, route of delivery, gender and birth weight. Overall, infants delivering within 7d had a lower incidence of receiving respiratory support for >24 hours (62% vs 81%, P ! .01), but there were no significant differences between the groups in need for surfactant (39% vs 47%), mechanical ventilation (49% vs 59%), NEC (6% vs 4%), IVH (15% vs 20%), oxygen dependence at 28d (24% vs 23%) or at 36 weeks EGA (13% vs 12%), length of stay (34 d vs 38 d) or mortality (2 vs 0). These results were no different when evaluating only infants delivered before 30 weeks. Further, for those infants who delivered greater than 7 days after AS, there was no association between increasing time intervals after AS and neonatal morbidity. The power to observe a 50% reduction in surfactant use and mechanical ventilation was 94% and 99%, respectively. CONCLUSION: Among infants exposed to a single course of AS, delivering more than 7 days after initiation of treatment did not appear to be a disadvantage. These data challenge the concept of diminishing efficacy of steroids after 7 days, and question the need for considering a rescue course. 383 THE ASSOCIATION OF FETAL GENOTYPE FOR THE MTHFR GENE AND PRETERM PREMATURE RUPTURE OF MEMBRANES AMIE HOLLARD, RHONDA FLORA, PAMELA RUMNEY, JUDITH CHUNG, MICHAEL NAGEOTTE, University of California, Irvine, Maternal Fetal Medicine, Lincoln, Nebraska, University of California, Irvine, Maternal Fetal Medicine, Orange, California, Long Beach Memorial Medical Center, Maternal Fetal Medicine, Long Beach, California OBJECTIVE: Methylenetetrahydrofolate reductase (MTHFR) plays a role in folate/homocysteine metabolism. The common polymorphisms in the MTHFR gene are C677T and A1298C, the presence of which has been associated with adverse pregnancy outcome. Given that folate and homocysteine are involved in collagen synthesis, we hypothesize the presence of MTHFR mutations in the fetus may increase the risk for preterm premature rupture of membranes (PPROM). STUDY DESIGN: A nested case control pilot study of 2 groups. Group I (n = 18): patients with PPROM delivering between 24 and 35 weeks. Group II (n = 25): patients without PPROM delivering between 24 and 42 weeks. Patients with diabetes, hypertension, preeclampsia, or multiple gestations were excluded. At delivery, a placental biopsy was obtained. The fetal RNA was extracted and multiplex PCR/ RFLP was performed for the presence of C677T and A1298C alleles. Univariate analysis, Chi-Square, Fisher’s Exact, & unpaired t tests were used as appropriate. Significance was set at P ! .05. RESULTS: The allele frequencies for C677T & A1298C are 28% & 44%, and 48% & 44% for Group I and Group II respectively . In Group II, there was an equal distribution of of the alleles between patients delivering at ! or >34 weeks gestation. In the Caucasion patients, 100% of Group I patients and only 60% of Group II patients had one or more mutations present. However, in the combined population there was no overall increased risk of PPROM if the fetus had one or more C677T P = .31) or A1298C mutations (P = .98). CONCLUSION: In our study, it appears that the presence of fetal C677T and A1298C polymorphisms are not uniquely associated with PPROM, but it may influence PPROM in certain ethnic groups. The effect of maternal genotype was not evaluated in this study, there may be additive effect when both genotypes are considered concurrently. An unexpected finding in this study was the large number of control patients with either mutation. A larger sample size is needed to discern if a true association is found between the presence of MTHFR mutations and PPROM.