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388 spa Abstracts

RENIN IN UTEROPLACENTAL COMPLEX IN PREECLAMPSIA. D.M. Shah, M. Grant, K. Higby, Dept. of Ob/Gyn, The University of Texas Health Science Center at San Antonio. OBJECTIVE: To estimate the net change in renin concentration in the uterine circulation in preeclampsia. STUDY DESIGN: Patients with preeclampsia and an anterior/fundal placenta undergoing cesarean section for clinical indications were recruited for the study. Patients with acute fetal distress and/or clinical evidence of infection were excluded from the study. Informed consent was obtained to aspirate blood samples from the uterine venous sinus at the placental interphase prior to delivery. Simultaneously, radial artery and peripheral vein samples were also obtained. Radial arterial samples were collected to represent uterine arterial renin levels. Plasma renin concentration was measured by RIA for angiotensin I (AI) after AI generation. Uterine, arterial and peripheral venous plasma renin concentrations were compared by paired t­tests. RESULTS: Plasma renin concentrations (n = 6) are presented as mean ± SEM. Peripheral venous renin concentration was 11.4 ± 4.3 ng Allmllhr. Arterial renin concentration was higher: 12.25 ± 4.7 ng Alimllhr.Uterine renin concentration was highest at 14.3 ± 5.1 ng Allmllhr. The uterine renin level was significantly higher (p < .02) than the peripheral venous level. There is a net los5 of renin in peripheral circulation, whilst there is a net increase of renin at 2.9 ng/ml in uterine circulation in preeclampsia. CONCLUSION: Our data show that there is a net positive contribution of renin in the uterine circulation in preeclampsia. It is speculated that this renin may participate in the pathophysiology of preeclampsia.

MAGllETIC RII8O\WICl! IMAGI&G va CctIPU'l'BD !J.'OI«lGIIAPHY '1'0 BVlILt1A'l'B 'l'BB x x

BRAIB I. ECLAMPSIA M Caine~ A Miranda, R Thomas, L Lin, J x -----

Doyle , Dept . Ob-Gyn, Radiology & Neurology, Western Pennsylvania

Bosptial, Pittsburgh, PA

OBJEC'l'IVB: Computed tomography (CT) has been recommended in order

to evaluate bleeding and/or cerebral edema after an eclamptic

seizure. Surprisingly a large number are reported as normal. We

chose to compare magnetic resonance (MIt) imaging to CT scanning 1n

order to determine if brain injury occurs.

STUDY DEBIGJI: We prospectively evaluated 8 patients with

eclampsia. 7 patients had tonic-clonic seizures and one a coma..

All patients had blood pressure ~l40/90 and .,::.+1 proteinuria prior

to or immediately after the seizure. All bad headache (7/8) or

blurred. vision (2/8) prior to seizing. 418 patients were

diagnosed preeclamptics and receiVed prophylactic magnesium

sulfate. CT scans were performed within 48 hours of seizure and

MR scans were performed within 1 week. 50% of patients had

follOW-Up MR scan ~1 month from 1st MR.

RESULT: 3/8 (38%) CT scans were normal, 2 abnormals were probably

normal (1 intarct vs artifact a nd 1 re-read as normal). Only 1 CT

scan was definitive (subdural hematoma, right falx). 5/8 (63%) MR

images were abnormal. 4/5 had increase in T2 weighted images

(localized areas of increase water content). The comatose patient

had increase 1n T1 weighted images di ffueely throughout the brain

read as petechial hemorrhages. Neurologically, 3 patients became

encephalopathic (I severe) and 1 patient had focal s1gns.

Clinical findings correlated with imaging studies in 50% of cases.

All patien-cs recovered. Follow-up MR scans were normal.

cafCLUSIOR: MR imeging identifies localized brain injury (most

likely cerebral edema) more often than CT scanning.

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331

January 1993 Am J Obstet Gynecol

COMPARISON OF PERIPARTUM MATERNAL CEREBRAL BLOOD FLOW VELOCITY CHANGES IN NORMOTENSIVE AND PREECLAMPTIC PATIENTS. K Wjlljams C. MacLean. Dept. of Ob/Gyn, Div. Mat. Fetal Med, UBC Vanc. B.C. Canada. OBJECTIVE: We hypothesized Ihat Maternal Cerebral Vessels react differently in the post partum period in preeclamptic patienls as compared to normotensive patients. STUDY DESIGN: Adull cerebral blood flow velocity (COFV) can now be assessed in the middle cerebral artery (MCA) by a non-invasive transcranial doppler lechnique using a 2MHz pulse wave transducer developed by Aaslid. We assessed middle cerebral artery blood flow velocilY (MCBFV) in 23 normotensive patients and 46 preeclamptic patients using a bi-directional pulse wave doppler ("flow scan plus") Appleton Chilworth, U.K. with a MHz probe and a fasl fourier transform real-time spectrum analyzer. With the patienl in the semi-recumbenl position both (MCA's) were insinuated through the maternal temporal ultrasound windows al a depth of 50-55 mm. (MCBFV) was performed during labour. 24 hours poslpartum and 48 hours posl-partum. We assessed mean MCA velocity. Slatistical significance was assessed using a paired I test. RESULTS: Middle Cerebral Arlery mean peak; yelocily and (S D)

Ante- 24 hrs post- 48 hrs. post-partum partum partum em/sec cmlsec emlsec

Normotensive 56 ± 17 54 ± 1 57 ± 20 n=23

Preeclamptic 65 ± 17 77 ± 23 81 ± 20 n=46

We found (I) Middle Cerebral BFV was significantly higher in all phases of the peripartum period in Ihe preeclamptic group as compared to the normotensive group (2) No significanl change in the MCBFV in the normotensive group in the peripartum (3) A significant rise in the mean CBPV in the posl-partum (p>.01) in the preeclamptic group. CONCLUSIONS: Local circulatory changes occuring posl-partum in the preeclamptic group results in persistant cerebral vasospasm.

URIC ACID IS LINKED TO OXIDATIVE STRESS IN PROTEINURIA PREECLAMPSIA. J J Walker, S Wisdomx. Rhoda Wilsonx , J McKillopX. University Departments of OB/GYN and Med, Glasgow Royal Infinnruy, Glasgow. UK. OBJECTIVE: Uric acid Is formed from the action of xanthane oxidase In response to Ischaemia. The superoxide anion Is also produced. This study aimed to Investigate whether the rise In uric acid In preeclampsia {PEn was related to changes In oxidative stress. STUDY DESIGN: 32 primigravida with PET were studied for levels of uric acid. platelet count. and both extracellular (plasma thlol (PSH) and caeruloplasmln {CPJI and intracellular (lysate thiol (LSH) and superoxide dlsmutase (SOD)) antioxidants. 19 were non-protelnurlc and the other 13 had at least 0.3gm/24hrs of proteinuria. The results were analysed by multiple regression analysis. RESULTS: There was no association between any of parameters In the non-protein uric PET group. There was a strong association (p<0.004) between uric acid and the SOD level In the protein uric group. The correlation coefficient (r) was 0.6 (p<0.05). CONCLUSIONS: Uric acid Is elevated In most patients with severe PET. It Is presumed to be due to renal impalnnent. This study suggests that at least some of the uric acid Increase Is associated with the actlv.lty of the superoxide anion. This could result from xanthane oxidase activity In the Ischaemic placenta. This could explain the correlation between uric acid levels and fetal outcome.