238

364 SPO Abstracts

UNTOWARD NEONATAL OUTCOME ASSOCIATED WITHRUYfURE OF PRIOR UI'ERINE SCAR. &..!&!!nJI:, R. Paul.Dcpt. Ob/Gyn, Univ. of Southern CA., School of Medicine, L.A., CA .. OBJECTIVE: To report the neonatal outcome and to evaluate the critical time limit for the delivery of the fetus in patients with uterine rupture. STUDY DESIGN: Patients with prior ccaarean delivery who ruptured their uterus from January I, 1983 and June 30,1992 were identified retrospectively. Uterine rupture was defined as symptomatic scar separation requiring operative intervention for acute fetal distress or maternal bleeding with hypotension or shock. RESULTS: Eleven thousand, four hundred and five of 15 ,475 (74%) women with previous cesarean section underwent trial of labor and 106 cases of uterine ruprure were identified. Seven medical charts could not be retrieved. Of the 99 cases of uterine rupture, 41 of them were llS50Ciated with total or partial extrusion of the fetuses into the abdomen. The neonatal mortality and morbidity in relationship to fetal extrusion into the abdomen are depicted as follows:

Fetal extrusion (N = 41)

No fetal extrusion (N = 58)

Neonatsl death 4 2 Umbilical artery pH < 7.0 28 12 5 • Apgar ..::;. 3 7 4 Cerebral dysfunction 3 2 Intubation < 24 hours 10 4

The neon8181 mortality and morbidity were s.gntficantly higher in uterine rupture associated with extrusion of fetuses into the abdomen. Overall,there were six cases of neonatal death. Of thcac six cases, four of them occurred in patients who exhibited fetal distress on admission and underwent immediate cesarean delivery . Thus, only two cases of neonatal death were associated with uterine rupture during trial of labor. A large number of newborn. had umbilical artery pH < 7.0 but molt of them had no adverse sequelae. Five newborns suffered cerebral dysfunction and 14 of them required intubation briefly forless than 24 hours. All the fetuses which were delivered within 13 minutes of the diagnosi. of fetal dilltrcSS (as manifest by only prolonged deceleration) did not suffer neonatal death, cerebral dysfunction or require intubation. CONCLUSION: Major neonatal complications asoociated with patients undergoing trial of labor arc rare. Untoward fetal and neonatal complications can be minimized in patients undergoing trial of labor aft.cr previous cesarean delivery by judicious attention to the fetal heart rate tracings and expeditious delivery of the fetus once fetal distress is diagnosed.

239 THE EFFECT OF RECENT COCAINE USE ON THE PROGRESS OF

LABOR. H.Webbeh· R. Matthews·, S. McCalla, J. Feldman·, H. Minkoff.

Dept ObiGyn, Kings County Hospital, SUNY HSC at Brooklyn, NY.

OBJECTIVE: Reports in the media havc sugestcd that cocaine usc may shorten

the course onabor. The publicity attached to th_ reports may inadvertently

increase the peripartum use of cocaine. In order to test the validity of these reports,

a study on the effects of cocaine use on the progress of labor was undertaken.

S111DY DESIGN: Data were gathered on a cohort of inner city women delivering

within 24 hours ofedmission ata municipal hospital in New York City in 1991-

1992. Urine specimens were obtained from women admitted for delivery and sent

for drug screen. The lengths of esch phase of labor were recorded prospccti .. ly

and linked to the results of the urine toxicology. Data were log transfomled and categorized into quartiles to minimize the impact of extreme durations of labor.

Analysis of covariance and exact tests for multiple contingencies tables were used to

compare duration onabor by cocaine use adjusting for other factors. For this

analysis, only women delivering vaginally were assessed.

RESULTS: Women who tested positivc for cocaine in their urine had significantly

shorter duration of labor than women who had tested negative. The geometric

mean of tbe number of minutes of labor from admission to birth, from 4-5 em to

fully dilated and from fully dilated to birth for women with vaginal deliveries was

assessed after controlling for parity. In every instance, cocaine users experienced a

shorter duration of labor with significance reached for the periods from admission

to birth and fully dilated to birth (P < .05). When adjusted for birth weight and gestation however, only the time between admission to birth remained statistically

significsnt (gm 157 v 321, P < (05), sugesting perhaps a difference in cervical dilatation at the time of admission. Similar results were obtained when labor times were ranked by quartilcs and compared. CONCLUSION: Aller adjusting for birthwcight aod gcststional age, there was no

chanae in duration of active phase or second stag" of labor in partorients who tested

positi .. for cocaine.

January 1993 Am J Obstet Gynecol

240 EPIDURAL ANAIGESIA NEED N:.1I' INFLUEOCE THE SPONrANEDUS VAGINAL DELIVERY RATEx M. R::l:::s:n, X

P. ~lan, P. 1>t: Parlarrl,X c. 1>t: Q.ri.1lan, M. 0' ~ll.x N:itiaBl t-Bternity H::!:pital, 1lb1in. CE.JKTl\E: Irrtrcdrt:i.rn of epidJral aralg::sja is lS.El1y ass:x::iata:l with a rire in tre q:erati\e <Eli~ rates. In tiE N:itiaBl t-Bternity H::!:pital, 1lb1in, Irelarrl, tre epidIral rate res in:::J:e3.caj fa.n:fo1d sirx:e 1987. In c:.t:d=r" tD naintain = Illij1 sp::n\:arHJ.E vcgiml <Eli~ rate v.e J:1:!Ili.e,.erl arrl c.rra:oq..atly ~ 0Jr 1lEIl~laIL of tiE first Tho st:q:s of laJ::or. SIUJf J:ESJI:N: ve o::npmrl tiE J.a:x:r rutn:rre of tre first th:1.Earrl, ffOIlan:U.E1y lalxrirg rullipm:1.E \>.OlB1, at term with a slrl)le fetu3, c::cpruic pre:BItatirn in 1987, with a s:irnilar gra.p of \>.OlB1 in 1992. REBElS: Epidlral rates v.ere 10% vs 45%. ~ vcgirnl <Eli~ rates v.ere 82% vs 82%, q:erati\e vcgirnl <Eli\el:y rates v.ere 14% vs 13%, arrl ce:;amm se:tim rates Y.ere 4% vs 5%. I.ffiJth of tre first sta::J= \tHe 5.5 vs 4.8 hrs, r:assi\e ~ of tre a:u:rrl sta::J= 0 vs 0.3 hrs, a±i\e J;hls= cf. tre a:u:rrl sta::J= 0.5 vs 0.6 hrs. CKytxrin rates v.ere 44% vS 55%, ITE£Il1 l:B::Jy v.ei<j1ts v.ere 3.47 vs 3.48 I<g an] Ilffil1 cerviaU d:i.latat.im at ainiss.irn W3S 1. 6 vs 1. 9 ~.

0lS. 'IlEre W3S TO sigrifiamt ctEr/;Je in p:riratal ncrbidit)' 0NIlBlIN: Epid..:Iral Ci"Blg::sja nay I:e cf. naj::r l::Erefit in lab:r ern rn:rl rrt::nrl..xE tiE dEn:e of "fU rt:a a:us vcgiml <Eli\el:y if tre r:assi\e ~ of a:u:rrl sta::J= lab:r is 1e-gthn2d.

241 PHOSPHOINOSmDB-SPECIPlC PHOSPHOLIPASB C (PI-PLC), THB OSCILLATOR FOR OXYTOCIN (0:9 STIMULATBD CONTRACTIONS. M.. ~ M. Frei) . Dept. of Ob/Gyn, University of ChM:ago, Chicago, IL. OBJBCI'IVH: The OT stimulated iDcrease in uterine COIItractioos is mediated by osciIJauoos of intrac:eUu1ar calcium. These studies were performed to test the bypothesis that PI-PLC is an euential compooent of this intraceUular osciIJator. STUDY DBSIGN: In vitro coatrac:tioII. studies were performed utilizing IoagitudiDal uterine strips from Sprague Dawley rats during metestrus. COIltractiIe ac:tivity was determiDed using isometric: traDlIducers coupled to an OMEGA PCL-718 A/D boerd-286 PC; digitalimJ data was analyzed to determine the area under the c:ootractiOll curve for 5 min intervals and uormaIized for • crosa-section area (ie. gram­seconds/minute/CID). Do&e reaponse studies were performed UIing OT and aluminum nuoride (AlF 4-' a G-protein/pI-PLC complex agonist) with/without 2-DitrO-4-carboxypbenyl-N,N­dipbenykarbamate (NCDC, a PI-PLC inhibitor). ItBSULTS: OT stimulated a IlignifIC8llt iDcrease in contractile activity (ANOVA, F=13.8, P<O.Ol). Stimulation of the G­protein/PI-PLC complex with AlF - produced a comparable increase in c:ontractile adivity (F:'\6.8,p<O.ol). Addition of NCDC resulted in a 90% reduc:tioo of OT stimulated eontractile adivity; &imilariy, NCDC produced a 66% reduc:tioo of AlF 4-stimulated c:ontractile adivity (both p<O.ol). CONCLUSIONS: These studies provide support for the bypothesis that PI-PLC plays an euentia1 role in the intrac:ellu1ar oscillation events oec:urriDg in uterine myoc:ytes that result in OT stimulated uterine cootnlctiODA. (flUlded by NIH "022(63)