400 SPO Abstracts

452 ANTEPARTUM AUTOLOGOUS BLOOD DONATION: COST/BENEFIT ANAL YS IS. CA Combs MD PhD', EL Murphy MD MPH', RK Laros, Jr., MD. University of California. San Francisco

To minimize the fisk of infection after homologous blood transfusion (TX). autologous blood donation (AuBD) has been recommended before procedures wi th a hi gh r; sk of TX. Antepartum AuBD has been shown to be safe for mother and fetus ; n pat; ents wi th "t rad; t; ana 1" r; sk factors for obstetr; c TX. However, the majority of units so donated are not needed for TX, except in patients with placenta previa. We attempted to develop rational recorrnnendati ons for antepartum AuBD based on actual r; sk factors for TX. We rev; ewed the TX experi ence ; n 14.267 consecut1 ve term del i veri es from 1978-88. Women with pl acenta prey; a were exc 1 uded. Preterm deliveries were excluded because these women could not have completed an AuBD program. Ten risk factors that could have been known in advance were studied. On multiple loglStic regression, four factors were significantly (P<0.05) associated with TX: preeclampsia (odds ratio=3.7), multiple gestation (OR=2.8), elective cesarean (OR=!. 7), and null iparity (OR=J.5). There was no associ at i on between TX and ethni c group, pri or abort; ons, pri or cesarean section, or prior postpartum hemorrhage. In a cost/benefit analysis, we assumed that the cost of a 2-unit AuBD was $100, the risk of hepatitis 1 in 20 homologous units, and the risk of HIV infection 1 in 40,000 homologous units. Lower infection rates would result in higher costs per case prevented by AuBD.

# of Risk # of Pts. Cost of AuBD to Prevent One Case of: Factors Transfused Homologous TX Hepatitis HIV

0 43/6218 (0. 7"~) $23.0K $161.8K $300. OM 1 83/7187 (1.1%) 11.6K 88.0K 136.9M 2 24/810 (3.0%) 4.3K 35.2K 73.6M 3 or 4 4/52 (8.0%) 1.3K 13.3K 26.0M

CONCLUSION: In obstetric patients without placenta previa, the probabi 1 i ty of TX or TX-re 1 ated infect i on is too low for antepartum AuBD to be cost-effective.

453 OUTPATIENT PROSTAGLANDIN E2 SUPPOSITORIES IN POSTDATES PREGNANCIES. SK Sawal, WF O'Brien, MS Mastroglannls, MG Mastry", GW Porter", L Johnsonx. University of South Florida, Tampa, Florida

Although the safety of low dose outpatient PGE2 for postdate pregnancy has been established (Obstet Gynecol 78:19, 1991), the efficacy and advantages remain unknown. We Investigated dally seH·admlnlstered 2 mg PGE2 vaginal suppoaltorles In accelerating cervical ripening In this double blind, placebo controlled study, 72 patients with uncomplicated pregnancies ~ 41 weeks gestation and a Bishop score of < 9 received either 2 mg PGE2 placebo or vaginal suppositories, The groups were comparable In age, parity, EGA, and Bishop score. Patients were admitted for labor Induction If the Bishop score was ~ 9, for unfavorable antepartum test results, or other obstetrical complications. There were no cases of stimulation of regular uterine contractions or reports of other side effects. The results were as follows CONTROL(40) PGE2(32) p Bishop score on L&D admission 11 10 NS EGA on L&D admission (days) 298 295 <.05 No. of suppositories 8 2 < ,05 Total oxytocin used (mU) 2192 484 <.05 Time In L & 0 (hrs) 12,2 8,4 <.05 C-sectlona 5 2 NS Antepartum testing costs (S) 664 506 <.01 CONCLUSIONS: 1. Dally 2 mg PGE2 suppositories accelerate cervical ripening resulting In earlier spontaneous or scheduled admission for labor 2. Low dose PGE2 may decrease Intrapartum cervical resistance as reflected by shortened labor course & decreased requirement for oxytocin, not necessarily reflected In the Bishop score,

January 1992 Am J Obstet Cynecol

454 CESAREAN BIRTH SOLELY TO PREVENT MECONIUM ASPIRATION SYNDROME UNWARRANTED. YR Renfroe" and SF Bottoms, Wayne State Univ" Hutzel Hospital, Detroit, MI.

The persistence of meconium aspiration syndrome (MAS) with meconium staining despite intrapartum suction has led some clinicians to perform cesarean birth to prevent gasping in cases with little evidence of fetal distress. To investigate the relationship between mode of delivery and MAS, we studied 2,523 consecutive singleton, vertex, live births complicated by meconium stained fluid delivered in 1987·89. Of these, 172 had a final clinical diagnosis of MAS. MAS was associated with Apgar score of 0·3 at 1 minute (p < 0.(01), fetal scalp pH < 7.W, (p<O.OI) and primary, repeat, and elective repeat cesarean delivery (p<O.D1 in each case). Discriminant function analysis revealed no relationship to mode of delivery in the absence of a low Apgar score or scalp pH. Dysfunctional labor, abnormal fetal heart rate patterns, and the duration of labor were not significantly related to MAS. There was a 6.8% incidence of MAS with meconium staining that increased to 28.4% with an Apgar score of 0·3 or scalp pH < 7.W, This is in sharp contrast to the reported 4% frequency of aspiration among meconium stained stillbirths, and suggests MAS is linked mainly to acidosis at the time of birth rather than before birth, We conclude that cesarean birth to prevent intrauterine gasping is unwarranted; severe acidosis should be avoided irrespective of the presence of meconium.

455 A PROSPECTIVE STUDY OF THE 30 MINUTE RULE IN THE TIMING OF CESAREAN DELIVERY FOR FETAL DISTRESS. T,R Moore M,D., W.M. Gilbert M.D., R. Resnik

M.D., R.c. Stevenson M.D.x Division of Perinatal Medicine, University of California San Diego, CA.

A limit of 30 minutes from the recognition of fetal distress until delivery is a commonly recognized standard, yet supporting data are lacking. We prospectively studied the effect of timing of cesarean section (decision·to·delivery time (DDT) and OR· to·delivery time) on neonatal outcome in 261 consecutive cesarean sections performed for fetal distress (FD) from 12/85 to 2/88. The time of onset of labor, the time of recognition of fetal distress, the FHR abnormality/scalp pH, time to OR, time of delivery, umbilical gases (UBC), and Apgars were recorded on a data sheet validated by independent review the following day, The mean DDT was 31 ± 27 (SO) minutes. FD deliveries were divided into DDT<3O' (66%) and >30' (34.%). The mean arterial UBG pH (7.23 ± ,09 vs 7.25 ± .08, p<,02), venous pH (7.28 ± .08 vs 7.31 ± ,07, p< .(04) were statistically but not clinically different. Fetal acidemia (arterial pH<7.15, venous pH<7.W), was more frequent in the DDT <30' group (16% vs 7%, p<.OOI), but the incidence of Apgar 5'<7 (3% vs 1%) and admission to NICU (W% vs 21%) was similar. This study suggests that, utilizing traditionally accepted indicators of fetal distress, immediate neonatal outcome is not influenced by the decision to delivery time.