256

257

370 SPO Abstracts

ETIOLOGIC PATHWAYS TO PRETERM BIRTH IN A SOUTHEAST­ERN U.S. POPULATION. M. Kathryn Menard and Thomas C. Hulseyx. Medical University of South Carolina. Charleston. s.c. OBJECTIVES: The purpose of this study was 1) to describe the etiologic pathways that result in pretenn birth (PTB) in an economically disadvantaged population and 2) todescribe the gestational age specific neonatal outcome within each pathway. STIJDY DESIGN: A retrospective cohort study of PTBs (23 to <37 completed weeks gestation) was perfonned using our hospital computerized perinatal database (1982-1991). Only patients with liveborn singleton gestations who received primary prenatal care through the public bealth system were included in the analysis. Frequency distributions were examined. Stratified analysis and logistic regression were performed to consider possible confounding variables. RESULTS: Of 2917 PTBs. 32% resulted from idiopathic pretenn labor (PTL). 37% from pretenn premature rupture of membranes (PPROM) and 36% were delivered for medical indications (e.g. severe preeclampsia. maternal bleeding, IUGR). The distribution was similar wben stratified by race. Compared to PTL. pretenn delivery for medical indications was morc frequent among tOOthers <18 years of age (RR= 1.5; 95%CI= 1.2-1.9). Forty-three percent of births <28 weeks gestation were due to medical complications. 37% PPROM and 20% PTL (p=O.OOOI). Neonatal mortality was higher among infants delivered due to PPROM (RR=1.7; 95%CI=I.1-2.5) or medical complications (RR=1.6; 95%CI=I.I-2.4) than due to PTL After adjusting for gestational age at birth, the risk of neonatal death was similar in PTL and PPROM. The risk of death remained elevated for infants delivered for medical complications. CONCLUSIONS: The distribution ofPTB by etiologic pathway is similartothat reported in other populations. Contrary to reports from other regions, blacks in this population do not have an increased proportion ofPTB due to PPROM. PTB for medical indications is a major contributor to neonatal mortality and appears to be a function of both gestational age at delivery and an additional risk related to the complications. Preventive strategies should be designed in the context ofthis epidemiologic data. Future efforts to reduce neonatal mortality due to PTB in this population sbould focus on the prevention of PPROM and PTB resulting from medical complications.

lII' I.UIJU OF !WI AlII £1IIIICIll til FIICIlItS NHCTltI; asrATltIW. IIif. DlsntllUTltII I

c, Inqardh • T.J . Sheehan, J. Kunhch - Dept OB/GYN. Hartford Hospltol,

Hartford. Cr. and Dept of 0.. Medicine. tkliversity of Conn . • F.,..ington. CT

OLI.CfIVE: To Issess the influence of ' race and ethnicily on other risk fictors

(YOking, obstttrical history) in dtte,..lning gestatlonll age distribution.

S1lIJI IlESIGI: As part of cny wide pretel'll birth prevention project, In new

prenatal patients 'Were interviewed by I te. of projects nurses (18-24 wtet GA). Of

these. 3140 .:.n with Iiv8orn. non·~lous singleton pregn.ncies for.erd the bish

of the stlKl)" Tke relationship of 14 risk fiCtors to pretel'll birth and gest.ttonal

age was detel'llined by bivarilnt and IlUlttvariant IItthods Including a factorial

analysis of variance with interKtions.

"U.TS: s.oking. history of obstetrical co.pHcations and rau/ethnidty elRrged

froe a 3 way analysis of vlrianc, as affecting gestational age (p= <.OOOl) for each of

the factors. Prior an.lysis had de.onstrat~ that U.S. blacks ~re significantly

different fr .. blacks of British West Indian ethnicity Ind different fre:. hlspanics

and ~ites in birth outeOM'. lhe interaction or synergistiC ,ffects of being aU,S .

black c<*lined with hhtory of obstetr ic.l COIIplicatioos was significant (.6'1 " 36.9)

eo.partd to others (.SA • 38.5) p. ".O(XJl. The effect of sU1ng was aho

sign if icant for U.S. blacks (xGA " 37.9) cOllPared to s.,klng in others (xSA " 39) p ..

< .0021. In the gravldlS ... Ithout a Mstory of obstetrical c.c.plfcations there was no

difference in GA distribution betWHft U.S. blitd,s CtIIIpirfll to all others (P~ . 9181).

SI.narTy there ws no difference in 6A distribution in nons_erSt ~ring U.S.

blacks and all others.

UIIl1J5,'CII: History of prior obstetrical cOllPlications and s.aking exerted a IIIOre

significant influence for U.S. blacts COIpared to other racial/ethnic groups . Risk

factors for poor perinatal outco.e .. st ~ viNe<! as it relates to race and ethnlcity.

258

.January 1993 Am J ObSLCL Gynccol

THE INCIDENCE OF PRETERM DELIVERY IS LOWER AMONG SOUTHEASTERN ASIANS WHEN COMPARED TO OTHER SOCIOECONOMICALLY DISADVANTAGED URBAN WOMEN_ C A RobjnsonX, I. Forouzan. P. Samuels. University of Pennsylvania Medical Center, Philadelphia, PA. Objective: We wanted to determine n poor urban Southeast Asian patients experienced the same rate of preterm delivery as other patients of similar socioeoconomic status living in the same geographic area. Study DeSign: To asses the influence of socioeconomic status and race on the incidence of prelerm delivery, we retrospectively studied the pregnancies of a group of Southeast Asian women (n_163), and compared the occurrence of preterm delivery with that found in a non-Asian control population (n-5743). Both groups were from similar socioeconomically disadvantaged urban areas and attended Ihe same public health or university clinics, and delivered in the same university hospital. All of the newborns were evaluated by the same group of neonatalogists. Preterm delivery defined as <37 completed weeks' gestation. Results: The rate of preterm delivery among the Southeast Asian (Vietnamese and Cambodian) population was 2.5% (4/163), compared with 9.6% (557/5743) for the control group (X2=8.853, p<0.01). Risk factors traditionally associated wtth preterm delivery, such as sexually transmitted diseases and poor prenatal care were equally distributed among both groups. Conclusions : There is a signnicantly lower rate of preterm delivery among Southeast Asian women in our geographical area. This difference appears to transcend the usual risk factors associated with preterm birth, leading us to reexamine our traditional model for preterm delivery.

259 COST OF NURSERY CARE BY RISK STATUS FOR PRETERM BIRTH. R BemjsX, MG Ross, M Sandhux. S Nessimx. JR Bragonie,x, CJ Habel. Dept. Ob/Gyn, Harbor-UCLA and Cedars Sinai Med. Ctrs., Torrance and Los Angeles, CA. OBJECTIVE: We have demonstrated a significantly reduced cost of newborn infant care from prenatally identified high risk women in the experimental versus control sites in the Los Angeles Prematurity Prevention Program (LAPPP).1 However not all preterm births were identified prenatally by our risk assessment system.2 We sought to determine if the costs of infant nursery care differed among women prenatally identified as high or low risk in the absence of intervention (control population). STUDY DESIGN: Double blinded risk assessment was performed in LAPPP control sttes from 1983 to 1986. Newborn nursery costs were determined for all preterm and a random sample of term infants of both high and low risk women delivering at Harbor-UCLA Medical Center. Hospital nursery charges were calculated in 1990 dollars. RESULTS: The mean cost of nursery care for preterm infants of high risk women ($24,178) was twice that of preterm infants of women identified as low risk ($12,243). The average weighted cost of nursery care for term and preterm infants from identified high risk women was $4.035 vs. $2,229 for prenatally identified low risk women (p = 0.01 ). CONCLUSIONS: Prenatally identified high risk women deliver more costly preterm and term infants than low risk women. 1 Ross et al. Am J Obstetrics and Gynecology, 1992;166:367. 2 Ross et ai, Am J Perinatology. 1986; 3:339-344.

Supported by CA Dept of Health Service, MCH Branch. Analyses and conclusions are those of the authors and not the State of CA.