612: late preterm infants - a group with significant morbidity

612 LATE PRETERM INFANTS - A GROUP WITH SIGNIFICANT MORBIDITY SUNIL JAIN1,SARAH CHENG2, SANGEETA JAIN3, KARIN A FOX3, GEORGE R. SAADE3, 1University ofTexas Medical Branch, Division of Neonatology, Galveston, Texas, 2University ofTexas Medical Branch, Pediatrics, Galveston, Texas, 3University of Texas MedicalBranch, Obstetrics and Gynecology, Galveston, Texas

OBJECTIVE: Late preterm infants (LPI) are infants born between 34 to 36w6dgestational age. The prevailing perception is that these infants do as well as terminfants. Recent reports showed that they have greater respiratory distress (RD) andhigher incidence of hyperbilirubinemia, feeding difficulties (FD), hypoglycemia,and temperature instability than term. Our aim was to evaluate the outcome of LPIstratified by gestational age.

STUDY DESIGN: We reviewed records (n�201) of LPI born at the University ofTexas Medical Branch. Infants with congenital anomaly or neuromuscular diseasewere excluded from study. Detailed pregnancy and maternal demographic datawere collected. The incidence of RD, jaundice, hypoglycemia & FD was compared.Data was analyzed using Chi square test for RDS, FD and jaundice(significance:p�0.05) and ANOVA for hospital stay.

RESULTS: The LPI constituted 9% of all deliveries, 35w4d as average gestationalage at delivery. Overall incidence of RD requiring oxygen with nasal cannula/ NC-PAP was 22%, jaundice requiring phototherapy was 46%, FD requiring gavage feedwas 22%, and hypoglycemia was 15%. The average hospital stay was 171 hours.Morbidity stratified by gestational age is shown in table (* shows significant differ-ence).

CONCLUSION: LPI need to be recognized as a separate group of infants associ-ated with greater morbidity than the term infants. Revised protocols need to beinstituted in the nurseries in managing these infants. Long term follow up is neededto study their neurodevelopmental outcome.

Morbidities in LPI stratified according to gestational age

Gestational age(weeks)

34 to 34.6(A)

35 to 35.6(B)

36 to36.6 (C) p

Respiratory distress 22 (32%) 11 (21%) 12 (15%) 0.04*Feeding difficulties 30 (44%) 7 (13%) 5 (6%) �0.001*Hyperbilirubinemia 43 (63%) 28 (52%) 25 (31%) �0.001*Average hospital

stay (hours)282 145 98 * A v/s B,

* A v/s C

0002-9378/$ - see front matterdoi:10.1016/j.ajog.2007.10.638

613 AMNIOTIC FLUID CAN BE STORED IN REFRIGERATOR WITHOUT DETERIORATION OFGROWTH FACTORS SUNIL K JAIN1, PETER UNTALAN2, SANGEETA JAIN3, ROBERTOGAROFALO4, GARY D.V. HANKINS5, 1University of Texas Medical Branch, Neonatology,Galveston, Texas, 2University of Texas Medical Branch, Division of Neonatology,Galveston, Texas, 3University of Texas Medical Branch, Obstetrics and Gynecology,Galveston, Texas, 4University of Texas Medical Branch, Pediatrics, Galveston,Texas, 5The University of Texas Medical Branch, Obstetrics and Gynecology,Galveston, Texas

OBJECTIVE: Necrotizing enterocolitis (NEC) is the most common gastrointes-tinal (GIT) complication of prematurity. In utero, the fetus swallows amniotic fluid(AF) which has growth factors (GF); epidermal growth factor (EGF), transforminggrowth factor-á (TGF-á), hepatocyte growth factor (HGF) and insulin-like growthfactor-1 (IGF-1). These are responsible for the maturation & development of GIT.In vitro and animal studies show that GF in AF have trophic effect on GIT epithe-lium & are protective against NEC. Whether the GF in AF are biologically active exutero, remains to be seen. In order to study that, we need to determine if GF in AFremains active after storage ex-utero for at least 7 days. We did a prospective studyto find out if AF can be stored for 7 days in the refrigerator without bacterialcontamination and deterioration of GF.

STUDY DESIGN: Preterm infants are generally too sick to be fed breast milk,good source of GF. AF could be a source of GF for first 5-7 days. With this hypoth-esis, we collected AF from 30 pregnant women undergoing elective cesarean sectionat term. Those with multiple gestation, fetal anomaly and known medical / preg-nancy complication, were excluded from the study. After collection, 10 mL of eachsample was stored at 4degree C for 7 days (Day 7). The remaining was stored at �80degree C (Day 0). GF were analyzed using enzyme-linked immunosorbent assay(ELISA) in Day 7 and Day 0 samples. Day 0 sample was divided into two: oneanalyzed before and other after pasteurization. Aerobic and anaerobic cultures ofDay 0 and Day 7 samples were done.

RESULTS: EGF, TGF-á and HGF were present in Day0 and Day7 samples withno significant difference in concentration. After pasteurization, HGF concentrationdecreased but EGF and TGF-á remained unchanged. No pathogenic bacterialgrowth noted in cultres.

CONCLUSION: Amniotic fluid can be stored for 7 days at 40 C without signifi-cant decrease in the concentrations of EGF, TGF-á and HGF. Amniotic fluid couldserve as a potential source of GF for GIT development in preterm infants to decreaseor prevent NEC.

0002-9378/$ - see front matterdoi:10.1016/j.ajog.2007.10.639

614 EVIDENCE IN SUPPORT THAT SPONTANEOUS PRETERM LABOR IS ADAPTIVE INNATURE: NEONATAL RDS IS MORE COMMON IN “INDICATED” THAN IN“SPONTANEOUS” PRETERM BIRTH JOONHO LEE1, HYO SUK SEONG1, BYOUNG JAEKIM2, JONG KWAN JUN1, ROBERTO ROMERO3, BO HYUN YOON1, 1Seoul National Uni-versity College of Medicine, Obstetrics and Gynecology, Seoul, South Korea, 2SeoulNational University Boramae Hospital, Obstetrics and Gynecology, Seoul, SouthKorea, 3National Institute of Child Health & Human Development/National Insti-tutes of Health/Department of Health & Human Services, Perinatology ResearchBranch, Detroit, Michigan

OBJECTIVE: The onset of premature labor has been proposed to have survivalvalue and to be adaptive. This hypothesis implies that induced preterm birth may beassociated with higher rates of complications than spontaneous preterm birth. Thepurpose of this study was to determine if there is a difference in the frequency ofneonatal respiratory distress syndrome (RDS), the most common neonatal com-plication, as a function of the etiology of preterm birth (e.g. preterm labor [PTL],preterm PROM, or pregnancies which ended because of maternal-fetal indica-tions).

STUDY DESIGN: The relationship between the occurrence of RDS and the ob-stetrical circumstances leading to preterm birth was examined in 257 consecutivesingleton preterm births (gestational age: 24-32weeks). Cases with major congen-ital anomalies were excluded. The study population was divided into the two groupsaccording to the cause of preterm birth; 1) preterm birth due to PTL with intactmembranes or preterm PROM (PTL-PROM group) and 2) indicated preterm birthdue to maternal or fetal indications (indicated preterm birth group).

RESULTS: 1) RDS was diagnosed in 47%; 2) RDS was more common in indi-cated preterm birth than in PTL-PROM group (58.1% vs 38.4%, p�.002); 3) Caseswith indicated preterm birth had a significantly higher mean gestational age atbirth, but lower mean birth weight, lower rate of histologic chorioamnionitis andhigher rates of cesarean delivery, 5 min Apgar score of �7, and umbilical arterialblood pH of �7.15 than those with PTL-PROM group (p�.05 for each); 4) Mul-tivariate analysis demonstrated that indicated preterm birth group was associatedwith an increased risk of RDS after adjustment for confounding variables(OR�2.29, 95% CI 1.22-4.29).

CONCLUSION: 1) The rate of RDS is greater in “indicated” rather than sponta-neous preterm birth; 2) This observation supports the view that spontaneous pre-term labor is adaptive in nature.

0002-9378/$ - see front matterdoi:10.1016/j.ajog.2007.10.640

615 THE IMPORTANCE OF INTRA-AMNIOTIC INFLAMMATION IN THE SUBSEQUENTDEVELOPMENT OF ATYPICAL CHRONIC LUNG DISEASE JOONHO LEE1, KYUNG JOONOH1, JOO YEON LEE1, JOONG SHIN PARK1, ROBERTO ROMERO2, BO HYUN YOON1, 1SeoulNational University College of Medicine, Obstetrics and Gynecology, Seoul, SouthKorea, 2National Institute of Child Health & Human Development/National Insti-tutes of Health/Department of Health & Human Services, Perinatology ResearchBranch, Detroit, Michigan

OBJECTIVE: Atypical chronic lung disease (CLD) refers to CLD which developswithout respiratory distress syndrome (RDS). Intra-amniotic inflammation hasbeen implicated in the genesis of CLD. However, it is unclear if it plays a role in theatypical form. The objective of this study was to examine whether the intra-amni-otic inflammation is a risk factor for the development of atypical CLD.

STUDY DESIGN: A retrospective cohort study was undertaken to examine therelationship between atypical CLD and intra-amniotic inflammation in 70 patientswho delivered preterm neonates (gestational age: 24-32 weeks) within 5 days ofamniocentesis and whose neonates subsequently developed CLD. Atypical CLDwas diagnosed when the infant developed CLD in the absence of RDS. Amnioticfluid (AF) was cultured for aerobic and anaerobic bacteria and genital mycoplasmasand assayed for MMP-8. Intra-amniotic inflammation was defined as an elevatedAF MMP-8 concentration (�23 ng/mL).

RESULTS: 1) Atypical CLD was identified in 54.3%(38/70) of cases with CLD;2) There were no significant differences in the median gestational age at birth,median birth weight, and antenatal corticosteroid use between infants with atypicalCLD and CLD after RDS; 3) Preterm newborns who developed atypical CLD had asignificantly higher median AF MMP-8 concentration (median 10.8 vs 394.3,p�.002), median AF white blood cell count (median 6.0 vs 441.0, p�.011), andhigher rate of intra-amniotic inflammation (46.9% vs 76.3%, p�.011) than thosewith CLD after RDS.

CONCLUSION: 1) Intra-amniotic inflammation was present in 76.3% of new-borns with atypical CLD; 2) Atypical CLD is strongly associated with intra-amnioticinflammation; 3) Intra-amniotic inflammation confers a greater risk for atypicalCLD than for typical CLD (that which develops after RDS). These novel observa-tions strengthen the importance of prenatal inflammation as a mechanism of lunginjury.

0002-9378/$ - see front matterdoi:10.1016/j.ajog.2007.10.641

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S176 American Journal of Obstetrics & Gynecology Supplement to DECEMBER 2007