Volume 16~ Kurnber 1. Part 2

256 A M N lOT I C FLU I D SPECTROPHOTOMETRY IS USEFUL AFTER 20 WEEKS GESTATION IN THE CARE OF PREGNANCIES COMPLICATED BY RED BLOOD CELL ISOIMMUNIZATION Richard O'Sha.u&hnessy. M.D. and The Ohio State University Isoimmunization Program, Ohio State University Hospitals, Columbus, Ohio

Liley (1961) showed that amniotic fluid spectrophotometry in the third trimester is a useful indicator of the severity of fetal isoimmune hemolytic anemia. Its usefulness prior to 28 weeks gestation has been questioned. We evaluated amniotic fluid from 20 weeks gestation until delivery in 91 women with non­hydropic fetuses followed in our Isoimmunization Program over the period 1977-87. The amniotic fluid delta 00 450 was correlated with the cord hemoglobin at birth. The results indicate that delta 00 450 from 20-28 weeks gestation has a similiar predictive value to the delta 00 450 obtained from 28 weeks gestation until term. High values indicate severe disease; low values indicate mild disease; an area of overlap exists between these extremes which requires a trend of values to prognosticate severity. We conclude that amniotic fluid spectrophotometry is useful beyond 20 weeks gestation and that delta 00 450 can supplement cordocentesis in the early evaluation of the isoimmunized pregnancy.

257 UTERINE ACTIVITY USING AMBULATORY TOCODYNAMOMETRY AFTER INTRAVAGINAL PROSTAGLANDIN Ez (PGEz> FOR CERVICAL RIPENING. A Millerx, W Rayburn, C smith, K Allenx, T Banex. Dept ObjGyn, Univ Nebr Med ctr. Omaha, NE

In the present study, uterine activity was characterized using this pressure sensitive device in 40 women at term with an unfavorable cervix. The PGE2 was inserted using either a 2.5 mg gel (20) or 10 mg sustained release pessary (20) as part of a randomized drug trial. Uterine activity was monitored for 12 hours and interpreted according to guidelines by Scheerer (Obstet Gynecol, 1990). For those treated with the gel, uterine activity began within the first hour, reached a peak within the first 4 hours, and precipitated labor in 10 (50%) cases. with the pessary, uterine activity had a later onset, reached a peak between the third and fifth hours, and precipitated labor in 18 (80%) cases. uterine hyperstimulation occurred in 2 (10%) pessary cases only, with no adverse outcomes after removal.

SPO Abstracts 317

258 BIRTH TRAt:MA: A FIVE YEAR REVIEW OF INCIDENCE AND ASSOCIATED PERINATAL FACTORS. Perlow JH. WIgton TX, Hart JX. Strassner HT. Nageotte MP, Rush-Presbytenan I St Luke's MedIcal Center, Chicago, l11inois

In a populauon of 19,370 consecutive liveborn infants delivered between January 1, 1985 and December 31,1989, we studied the occurrences of neonatal clavicular fracture (NCF), facial nerve Injury (FNI) and brachIal plexus injury (BPI). In total, 87 NCF's, II FNI's and 17 BPI'~ of the newborn were IdentIfied. The inCidence per 1000 Itvebirths and per 1000 liveborn cephaltc Singletons deltvered vaginally for NCF was 4 5 and 5.7 respectively; for FNI 0.6 and 0.7 respectively, and for BPI 0.9 and 1.1 respectively. All Injunes were noted in term infants. The incidence of FNI decltned by 75% dunng the study period In

parallel with a Significant 47% decline in the use of midforceps (p=.04). The inCidence of the other two injuries remained essentially constant. To varying degrees, the data demonstrate that the occurrence of these injunes is associated statIstically more often with prolonged gestation, epidural anesthesia, prolonged or rapid second stage of labor, oxytOCin use, operative vaginal delivery, shoulder dystocia, macrosomia, low Apgar scores and a prevIOus maternal obstetric history of macrosomia, when compared to controls. New Information IS presented indicating that the presence of meconium in labor and the occurrence of neonatal hyperblltrubInemla are significantly a~sociatcd variables, while the use of episiotomy is not. When the data are analyzed by stepwise logistic regression analYSIS, the abiltty to predICt Injury IS greatest for NCF (44.2%), but less for BPI (18.8%) and FNI (091:). These findings suggest that birth injury remains a problem in current obstetriC pracuce and addluonal study IS warranted In an attempt to further decrease these occurrences.

259 COMPLICATIONS ASSOCIATED UITH AMNIOINFUSION FOR MECONIUM Paul Henslelgh MD PhD, Miriam Loots 8S*, and Lelgh Hilsinger MD*. Stanford Univ Med School, Santa Clara Valley Medical Center, Dept of Ob-Gyn, San Jose, CA.

Amnloinfusion has been reported to be a simple, lnexpensive and safe technique that reduces the incidence of meconium beLow the vocal cords and improves obstetric outcome when thlCk meconium 15 identified during labor. After adopting an amnioinfusion protocoL for women with thick particulate meconlUffi, we noted among the first nineteen consecutively treated patients certain adverse events WhlCh are analyzed in this report as posslble slde effects of amnioinfusion. ALL nineteen patients had internaL fetaL monitoring and received amnl0infusion through a second intrauterine catheter uSlng 1000 cc normaL saLine, repeated every six hours untiL the amniotic fLuid cleared of meconium or delivery occurred. ShortLy after amnioinfusion began three patients deveLoped hypertonus, variabLe decelerations became more severe or progressed to fetal bradycardia in five patients and one patient began having late decelerations. Amnioinfusion was stopped in these cases and other necessary interventions lncluded tocOlYS1S wlth intravenous terbutaline for two patients and cesarean dellvery for two patients. Desplte our intent to remove meconium by amnloinfusion, seven infants (37%) had meconium below the cords by laryngoscopic examlnation at b,rth. We conclude that more data is needed on safety and efficacy of amnioinfusion for thick and particulate meconium, before accepting thlS procedure into routlne practice.