297 THE ACTIVE MANAGEMENT OF RISK IN MULTIPAROUS WOMEN AT TERM:AN ASSOCIATION BETWEEN A HIGHER PREVENTIVE LABOR INDUCTION RATEAND A LOWER CESAREAN DELIVERY RATE JAMES NICHOLSON1,AARON CAUGHEY2, MORGHAN STENSON3, LISA KELLAR4, PETER CRONHOLM4,IAN BENNETT4, 1University of Pennsylvania, Family Practice and CommunityMedicine, Philadelphia, Pennsylvania, 2University of California, Berkley, Ob-stetrics and Gynecology, San Francisco, California, 3University of Pennsylva-nia, School of Nursing, Philadelphia, Pennsylvania, 4University ofPennsylvania, Family Medicine and Community Health, Philadelphia,Pennsylvania

OBJECTIVE: National primary cesarean delivery rates continue to increase.A recent study reported a lower cesarean delivery rate in nulliparous womenexposed to a new method of care. We wished to examine the associationbetween exposure to this new method of care and cesarean delivery rates inmultiparous women.

STUDY DESIGN: One hundred and twenty-three sequentially deliveredmultiparous women that had been exposed to the Active Management ofRisk in Pregnancy at Term (AMOR-IPAT) were identified. AMOR-IPATused the risk profile of each woman to estimate an optimal time of delivery,and delivery by the upper limit of that gestational age range was encouragedby offering labor induction. Cervical ripening was used prior to induction inpatients with a modified Bishops score !6. Random numbers techniques wereused to identify three hundred and four women that had received standardtreatment. Levels of salient birth outcomes in the two study groups were thendetermined and compared. Logistic regression was used to adjust for possibleconfounding.

RESULTS: The active management group had a significantly higher laborinduction rate (61% vs. 15.8%, OR 3.86 [2.87-5.19]) and a significantly lowercesarean delivery rate (0.8% vs. 9.9%, OR 0.08 [0.01-0.60]). Rates of thickmeconium and major perineal trauma were also significantly lower in theactive management group. No salient birth outcomes occurred at higher ratesin the active management group.

CONCLUSION: Multiparous women exposed to the active management ofrisk in pregnancy at term experienced better outcomes than those that receivedthe standard of care. These findings conflict with the long-standing belief thatlabor induction promotes adverse outcomes. This discrepancy is perhapsexplained by the use, in the active management group, of labor induction in a‘‘preventive’’ rather than ‘‘indicated’’ mode. A randomized controlled study isneeded to evaluate this new method of care.

0002-9378/$ - see front matterdoi:10.1016/j.ajog.2006.10.325

298 LABOR MANAGEMENT STYLES AND CESAREAN SECTION RATESJAMES GREENBERG1, OGOCHUKWU OKPALA1, THOMAS MCELRATH2, 1Brighamand Women’s Hospital, Obstetrics & Gynecology, Boston, Massachusetts,2Brigham and Women’s Hospital, Division of Maternal Fetal Medicine,Boston, Massachusetts

OBJECTIVE: To determine if modeled ‘‘less aggressive’’ labor managementinfluences c-section rates.

STUDY DESIGN: We created a model for ‘‘aggressive’’ labor managementwhich included use of forceps, VBACs, vaginal breech delivery and tolerancefor less reassuring fetal testing. ‘‘Less aggressive’’ interventions were use ofvacuums and elective repeat c-sections. ICD-9 and CPT code data werereviewed from all births at Brigham & Women’s and Massachusetts GeneralHospitals from 1997-2004. Total deliveries, neonatal birth trauma, method ofdelivery and the six most frequent indications for cesarean delivery wererecorded. The rates for these data were calculated and the trends were assessedusing a nonparametric test of trend.

RESULTS: There were 100,149 births (range: 10,652-13,417 per year) withan average c-section rate of 24.3% over the study interval. The trends aresummarized in Table 1. Statistically significant increasing trends includedincreasing rates for c-sections (C/S) overall and c-sections for ‘‘fetal distress’’(Dstr) and elective repeats (Elec). Statistically significant decreasing trendsincluded rates of forceps (Frp), vaginal breeches (Brc) and VBAC’s (VB). Therates of neonatal birth trauma (Tra) and vacuum delivery (Vac) wereunchanged.

CONCLUSION: Our data suggests the rise in cesarean section rates isassociated with a fall in obstetrical procedures and/or interventions which areperceived as aggressive even in the absence of data demonstrating better

neonatal outcomes. We hypothesize that in a more cautious medical environ-ment, obstetrical providers are less willing to tolerate uncertainty and have alower threshold for advocating abdominal delivery.

Table 1 Annual Rates (%) of Clinical Events

C/S Dstr Frp VB Brc Vac Elec Tra

97 21.5 3.8 3.6 36.4 0.31 4.8 7.2 2.898 20.8 3.8 3.2 39.0 0.22 5.0 6.6 2.799 22.5 4.6 3.1 32.3 0.21 4.8 7.1 2.200 22.4 5.0 2.2 34.2 0.17 5.4 7.1 2.401 24.2 5.5 1.7 25.5 0.19 5.1 8.2 2.602 25.4 6.2 1.8 25.7 0.20 5.9 8.9 3.303 28.0 7.0 1.7 24.0 0.10 5.6 9.3 2.404 29.2 7.3 1.9 19.8 0.07 5.3 10 2.1p= .01* .01* .02* .01* .02* .18 .03* .23

0002-9378/$ - see front matterdoi:10.1016/j.ajog.2006.10.326

SMFM Abstracts S99

299 DO INCREASING C-SECTION RATES LOWER THE RISKS OF SHOULDER DYSTOCIAOR BRACHIAL PLEXUS INJURY? JAMES GREENBERG1, SHRUTHI MAHALINGAIAH1,THOMAS MCELRATH2, 1Brigham and Women’s Hospital, Obstetrics & Gynecol-ogy, Boston, Massachusetts, 2Brigham & Women’s Hospital, Division ofMaternal Fetal Medicine, Boston, Massachusetts

OBJECTIVE: To determine if rising cesarean section rates are protectiveagainst shoulder dystocias and/or neonatal brachial plexus injuries.

STUDY DESIGN: ICD-9 and CPT code data were reviewed from all births atBrigham & Women’s and Massachusetts General Hospitals from 1997-2004.Total births, c-sections (C/S), forcep deliveries (Frcp), total operative vaginaldeliveries (OpV), infants weighing O4,500 gms delivered vaginally (Mac),shoulder dystocias (SD) and neonatal brachial plexus injuries (Erb) wererecorded. The rates for these data were calculated and the trends were assessedusing a nonparametric test of trend.

RESULTS: There were 100,149 births (range: 10,652-13,417 per year) withan average c-section rate of 24.3% during the study interval. The results andclinical trends are summarized in Table 1. A statistically significant increasingtrend was observed for the rate of c-section overall. Statistically significantdecreasing trends included forcep delivery and total operative vaginal delivery.The rates of shoulder dystocia, brachial plexus injuries and macrosomicvaginal delivery were unchanged.

CONCLUSION: Our data suggest a rise in cesarean section rates is notprotective against shoulder dystocias or neonatal brachial plexus injuries eventhough the rate of macrosomic infants delivered vaginally was unchangedconcomitant with a drop in the rates of forceps deliveries and overall operativevaginal deliveries. These finding are consistent with the observation that bothshoulder dystocias and neonatal brachial plexus injuries have proven to bedifficult to predict and prevent.

Table 1 Annual Rates (%) of Clinical Events

C/S Frcp OpV Mac SD Erb

1997 21.5 3.6 8.4 1.9 1.1 0.121998 20.8 3.2 8.2 2.3 1.1 0.21999 22.5 3.1 8.0 2.4 1.0 0.122000 22.4 2.2 7.6 1.9 1.3 0.142001 24.2 1.7 6.7 2.0 1.0 0.162002 25.4 1.8 7.6 3.4 1.5 0.112003 28.0 1.7 7.3 3.8 1.2 0.192004 29.2 1.9 7.2 3.4 1.0 0.09p= 0.01* 0.02* 0.03* 0.08 0.41 0.41

0002-9378/$ - see front matterdoi:10.1016/j.ajog.2006.10.327