14–17 September 2014, Barcelona, Spain Short oral presentation abstracts

OP01.10Fetal echocardiography predicts postnatal treatment strategyfor the fetus with pulmonary atresia or severe pulmonarystenosis

L. Cao1, J. Rychik2, Z. Tian2

1Ultrasound, Nanjing Maternity & Child Health Hospital,Nanjing, China; 2Fetal Heart Program at the Cardiac Center,Children’s Hospital of Philadelphia, Philadelphia, PA, USA

Objectives: Fetuses with pulmonary atresia or stenosis with intactventricular septum (PA/IVS) also have variable degrees of rightventricle (RV) hypoplasia, which influences postnatal surgicalstrategies. Fetal echocardiography may predict single ventricle versusbiventricular repair after birth.Methods: We reviewed fetal echos of 36 fetuses (23 pulmonaryatresia; 13 severe pulmonary stenosis) diagnosed from 2008–13. Allfetuses had more than two studies prenatally and postnatal followup, evaluation, and treatment at the same center. Measurementsincluded: tricuspid valve and mitral valve diameter and Z score infour chamber view, presence and degree of tricuspid regurgitation,presence of subaortic stenosis, and presence of coronary arteryfistula. Doppler derived velocities and pulsatility-indices (PI) inmiddle cerebral artery (MCA) and umbilical artery (UA) were alsoevaluated. Subjects were divided into: 1) postnatal single ventriclerepair (group I), or 2) biventricular repair (group II). Data werecompared via student t tests.Results: Fetuses with 3rd trimester tricuspid valve Z score < -3and no tricuspid regurgitation underwent single ventricle repair(n = 16), while those with tricuspid valve Z score > −3 andmoderate or severe tricuspid regurgitation achieved biventricularrepair (n = 20). Tricuspid valve Z score was significantly lower ingroup I (−5.07 + 0.93 vs −1.67 + 0.83; P < 0.01). Two fetuses withsubaortic stenosis and coronary artery fistula had mid-gestationaltricuspid valve Z score > −3 at 1st study, which then fell to < −3in the 3rd trimester. Peak systolic velocities of the MCA becameprogressively higher with gestational age in all fetuses. In the 2ndtrimester MCA/UA PI ratio was significantly lower in group I(1.52 + 0.39 vs 1.89 + 0.68; P < 0.05).Conclusions: Fetal tricuspid valve Z score and degree of tricuspidregurgitation predict RV adequacy and postnatal strategy in PA/IVS.MCA/UA PI ratio may indirectly reflect vascular flow patterns andmay be an early predictor of future RV adequacy.

OP02: PRETERM LABOUR

OP02.01Quantitative ultrasound backscatter parameters in the humancervix

Q.W. Guerrero1, L. Carlsen1, H. Feltovich2,1, T.J. Hall1

1Medical Physics, University of Wisconsin, Madison, WI,USA; 2Maternal Fetal Medicine, Intermountain Healthcare,Provo, UT, USA

Objectives: Previous studies demonstrated that collagen in thecervix is aligned and layered, and that the shear wave speed increasesalong the length of the cervix. This suggests a structural changethat might also influence cervical assessment with quantitativeultrasound (QUS). This study was designed to investigate thepossibility of anisotropic, spatially dependent attenuation and excessbackscattered power loss (eBSPL) in ex vivo cervix tissues.Methods: Cervix specimens (N = 14) were collected from pre-menopausal women undergoing hysterectomy for benign reasons.

The specimens were scanned along the full length of the cervix witha Siemens Acuson S2000 using the 18L6 linear array. Echo datawere collected with beam steering from -40o to +40o in steps of 4o.Reference phantom data were similarly collected, and attenuationand eBSPL were calculated. The internal and external os were usedto group QUS parameter estimates among cervix specimens basedupon fractional distance along the canal.Results: The mean attenuation varied among spatial locations (3.04dB cm−1 MHz−1 vs 2.43 dB cm−1 MHz−1 at the distal andproximal ends, respectively). The standard deviation of attenuationshowed a decreasing trend along the cervical canal (1.11 dB cm−1

MHz−1 vs 0.757 dB cm−1 MHz−1 at the distal and proximalends, respectively). Attenuation estimates also displayed anisotropyat some spatial locations (0.6 dB cm−1 MHz−1 average differencebetween the -40o and +40o estimates at the mid-proximal location).Findings for eBSPL estimates were consistent with the attenuationtrends.Conclusions: As found for shear wave speeds, there is con-siderable spatial variability in QUS parameters in the normalnonpregnant cervix. In addition, there is strong evidence foranisotropy in these parameters which is consistent with alignedcollagen structures influencing acoustic properties. Accounting forthese sources of variance is important in cervical assessmentwith QUS.

OP02.02First-trimester maternal biochemical markers as predictors ofspontaneous early preterm delivery

M. Parra-Cordero1,2, A. Sepulveda-Martınez1, G.I.Rencoret2, G. Juarez1, F.J. Diaz1

1Fetal Medicine Unit, Obstetric & Gynecology Department,University of Chile, Santiago, Chile; 2Fetal Medicine Unit,San Borja Arriaran Hospital, Santiago, Chile

Objectives: The aim of this study was to evaluate whether maternalbiochemical markers are altered during the first trimester ofpregnancy and its role as a screening test for spontaneous earlypreterm delivery (sPTD).Methods: Biophysical (cervical length and uterine artery Doppler)and biochemical markers (maternal α-fetoprotein [AFP], matrixmetalloproteinase-9 [MMP-9] and TNF soluble receptor 1[TNF-R1]) were assessed at 11-13 weeks’ gestation in a case-controlstudy which included 16 women who later developed sPTD before34 weeks and 49 matched controls delivering after 34 weeks. Thedistribution of measured biophysical and biochemical markers in thecontrol and sPTD before 34 weeks were compared. Logistic regres-sion analysis was used to evaluate if any variable was significantlyassociated with sPTD before 34 weeksResults: Neither cervical length, uterine artery Doppler and TNF-R1were associated with sPTD. The maternal MMP-9 and AFP weresignificantly correlated with gestational age at delivery (r = −0.28and −0.26, respectively). However, the median AFP at 11-13weeks was the only biochemical marker assessed in this studythat was significantly higher in women who later delivered before34 weeks gestation compared to control (15.5 [12.8–28.7] vs 12.6[5.6–20.4], p = 0.03). Logistic regression analysis demonstrated thatAFP provided a significant contribution in the prediction of sPTDbefore 34 weeks, being the detection rate, at a fixed 10% falsepositive rate, at around 31%.Conclusions: Firstly, the finding of this study that MMP-9 and AFPwere negatively correlated with gestational age at delivery supportsthe hypothesis that sPTD might be associated with altered spiralartery remodeling and placental damage. Secondly, the increasedmaternal AFP was the only marker that improves the detectionrate of sPTD during the first trimester of pregnancy. Supported byFondecyt #1130668

Ultrasound in Obstetrics & Gynecology 2014; 44 (Suppl. 1): 62–180. 65