589 antenatal evaluation of fetal hindbrain herniation: mri vs. ultrasound

Volume 185, Number 6 A m J Obstet Gynecol

589 ANTENATAL EVALUATION OF FETAL HINDBRAIN HERNIATION: MRI VS. ULTRASOUND KATIE CLARK 1, JOSEPH BRUNER 2, GEORGE DAVIS1; 1Vanderbilt University, Obstetric and Gynecology, Nashville, TN; 2Vanderbilt University, Obstetrics & Gynecology, Nashville, TN

OBJECTIVE: To determine if tetal h indbrain herniat ion (FHBH) can be reliably diagnosed or graded in utero by ul t rasound imaging.

STUDY DESIGN: MRI remains the s tandard for diagnosis and grading of FHBH. In an effort to decrease costs associated with presurgical evaluation prior to in utero repair of open spina bifida, 61 patients were evaluated for FHBH utilizing magaletic resonance imaging (MRI) a n d / o r ul t rasound (US). 36 pat ients were evaluated by both. Results were g raded by presence and severity utilizing established cri teria for MRI and an US system that i nco rpora t ed appea rance of the cisterna m a g n a a n d cerebel lum, lateral ventriculomegaly, size of the third ventricle and Chiara II malformation. MRIs and ultrasounds were read by different examiners who were blinded as to each other 's impressions. Results were then compared.

RESULTS: With N = 36, there was an 80% power to detect a correlation of at least .45 (significantly diiterent than zero). The esthnated kappa was only 0.2 (CI 0.0 to 0.4). Separat ing n o r m a l / m i l d f rom modera te / seve re yielded a sensitivity of 100% but a specificity of 10%. Separating moderate fi'om severe yielded a sensitivity of 72% and a specificity of 57%.

CONCLUSION: Ultrasound is a poor predictor of MRI results with a lot of no rma l /mi ld FHBH being overcalled as moderate/severe. Table MRI vs ultrasound grading of FHBH

US W N L MILD MODERATE SEVERE TOTAL

MRI WNL 0 0 3 1 4 Mild 0 1 1 5 7 Moderate 0 0 8 6 14 Severe 0 0 3 8 11 Total 0 1 15 20 36

591

SMFM Abstracts S241

MORBIDITY AND MORTALITY OF SMALL AND ADEQUATE FOR GESTA- TIONAL AGE NEONATES BETWEEN 28-32 WEEKS' GESTATION RELI HERSHKOVITZ t, EHUD ZMORA 2, BORIS FURMAN 3, ASHER BASHIRI 4, ILANA SHOHAM-VARDI 5, MOSHE MAZOR4; ]Soroka University Medical Center, Ben Gur ion University of the Negev, OB/GYN, OMER; 2Soroka University Medical Center, Ben Gurion University of the Negev, Neonatal Unit, Beex:Sheva; 3Soroka University Medical Center, Ben-Gurion University of the Negev, OB/GYN, Beer-Sheva; 4Soroka University Medical Center, Ben Gurion University of the Negev, OB/GYN, Beer-Sheva; 5Ben-Gurion University of The Negev, Epidemiology Unit, Beer-Sheva

OBJECTIVE: To compare outcome of small and adequate for gestational age (SGA, AGA) neonates between 28-32 wks'.

STUDY DESIGN: 265 live neonates between 28-32 weeks' were bo rn dur ing 1995-1998; 11.7% (31/265) were SGA and the r ema in ing 88.3% (234/265) were AGA. Neonates with congenital malformations were excluded. SGA and AGA were defined as birth weight (BW) <10th and between 10th-90th percentile. Neonatal mortality (NM) was defined as neonatal death by 28 days of age/1000 deliveries.

RESULTS: The rate of preeclampsia was higher among premature SGA (33% vs. 13%, P-0.01). Steroid t reatment did not differ between groups (56.5% vs 56.2%, NS). NM was higher among SGA between 28-29 and 30-32 wks' (102 vs. 58, pO.01; 67 vs. 24, p4).01; respectively). The rates of RDS and BPD were lower among SGA (27% vs. 48%, p~0.01; 6% vs. 20%, p4).05,) and NEC was higher (16% vs. 5%, p4).02). Logistic regression revealed that gestational age (GA) and BW were independent risk t~tctors for survival (OR 0.55, OR 0.68) while GA only was significant for RDS (OR 0.70) and BPD (OR 0.68). GA, BW a n d preeclampsia were significant for NEC (OR 0.72, O R 0.52, O R 4.75; respectively).

CONCLUSION: Although the rate of NM was h igher among premature SGA neonates, the rate of RDS and BPD were lower. The rate of NEC was higher. These differences suggest that impaired fetal growth is a process re- sulting with different adaptat ion to extrauterine life.

590 PRENATAL ALCOHOL EXPOSURE AND REDUCED HEAD cIRCUMFER- ENCE AT AGE 7 ROBERT SOKOL1, JOSEPH JACOBSON 2, SANDRAJACOB- SON 3, LISA C H I O D O 4, JAMES JANISSE 5, JOEL AGERS; 1Wayne State University, Obste t r ics /Gynecology, Detroit, MI; 2Wayne State University, Detroit , MI; 3Wayne State University, Psychiatry; 4Wayne State University, Detroit , MI: 5Wayne State University, Cente r for Heal thcare Effectiveness Research, Detroit, MI

OBJECTIVE: It is well established that prenatal drinking is associated at birth with decreased head circumference. The purpose of the present study is to determine whether this effect persists into the early school years.

STUDY DESIGN: 234 mothers and children were studied prospectively f rom the prenata l per iod onward. The outcome variable was head circmn- ference at age 7 years. The i n d e p e n d e n t variable was the p ropor t i on of dr ink ing days-across-pregnancy, log t ransformed. Control variables were propor t ion of prenatal visits on which cocaine use was reported, cigarettes/ day, inaternal age (< 30 vs _> 30), SES (Hollingshead), prepregnancy body mass index, paternal height and infant sex.

RESULTS: There was no main effect for any substance after adjustment for the control variables, but there was a significant mate rna l age by alcohol interaction. In the unde r 30 group there was no effect of alcohol, while in the 30 and older group there was a strong negative effect. Evaluated by logistic regression, compared with no substance use, dr inking at least once per week was estimated to increase the small head circmnference rate (< 10th percentile for age) from 1% to 11%, a 10-fold increase (odds ratio), while dr inking at least twice per week increased the rate to 18% an 18-fold increase.

CONCLUSION: The finding of a reduced head circumference effect of prenatal dr inking on growth and development for older but not for younger mothers is consistent with similar f indings previously repor ted for cer tain cognitive effects in the offspring. The reasons for such age-by-alcohol in terac t ion effects on development remains speculative. These results do suggest that it is particularly important that public health messages concerning alcohol exposure risks for the fetus reach these older mothers.

592 MIDTRIMESTER PLATELET ACTIVATION AND ABNORMAL UTERINE ARTERY VELOCIMETRY ARE ASSOCIATED WITH RECURRENT PREG- NANCY COMPLICATIONS RELI HERSHKOVITZ 1, OFFER EREZ MD ~, MORDECHAI HALLAK 3, ELI MAYMON 4, MOSHE MAZOR 4, AARON TOMERS; 1Soroka Univeristy Medical Center, Ben Gurion University of the Negev, OB/GYN, OMER; 2Soroka University Medical Center, OB/GYN, Beer Sheva; ~Ben Gur ion University Soroka Medical Center, Beer Sheva, Israel; 4Soroka University Medical Centex, Ben Gur ion University of the Negev, OB/GYN, Beer-Sheva; 5Soroka University Medical Center, Ben Gur ion University of the Negev, Hematology Unit, Beer-Sheva

OBJECTIVE: During different stages of platelet activation (PA) Annexin and CD62p are expressed on its cell surface. The phenomenon was linked with placental insufficiency. This study was conduc ted to explore relat ionship between midtrimester PA and uterine artery (UA) Doppler velocimetry and subsequent development of pregnancy complications in a high-risk population.

STUDY DESIGN: Forty-five h igh risk p r e g n a n t women (history of preeclampsia, placental abrupt ion or habitual abortions) between 18-24 wks' were enrolled in a prospective study. Annexin and CD62p (flow cytometry) and UA Doppler velocimetry were determined. Annexin level>l% of activa- tion, CD62p >0.7 fluorescence unit and UA resistance index >95th percentile or an early diastolic notch were considered abnormal.

RESULTS: 42.2% (19/45) patients had PA function. 40.0% (18/45) had abnormal UA Doppler results and 36.5% (16/45) had both PA and abnormal UA velocimetry. 37.8% (17/45) women had severe preeclampsia(PE) and 33.3% (15/45) had small for gestational age (SGA) neonates. Overall, 57.8% (26/45) women had either PE or SGA neonate. Relationship between presence of at least one complication and abnormal UA, PA and the combinat ion is displayed in Table. Sensitivity, specificity, positive and negative predictive values (PPV, NPV) for PA are: 50%, 68%, 68%, 50%; respectively, and for combinat ion of PA and abnormal UA blood flow velocimetry: 54%, 90%, 88%, 59%, respectively.

CONCLUSION: Midtrimester PA is associated with recur ren t complica- t ions in high-risk popula t ion . Moreover, by using combina t ion of PA and abnormal UA blood flow velocimetry, the specificity and PPV are better than by using PA alone.

Table

N O COMPLICATIONS COMPLICATIONS-

N-26 19 P

Abnormal UA 12 PA 13 Abnormal UA+PA 14

6 .32 6 .04 2 .01