Prospective ultrasound measurement of placenta using panoramic view

S182 SMFM Abstracts 650

ULTRASOUND EVALUATION OF ABNORMAL UMBILICAL CORD COILING IN SECOND TRIMESTER OF GESTATION AS A PREDICTOR OF ADVERSE PREGNANCY OUTCOME MLADEN PREDANIC1, SRIRAM C. PERNI2, STEPHEN T. CHASEN2, REBECCA N. BAERGEN3, FRANK A. CHERVENAK2, 1Cornell University, Obstetrics and Gynecology, New York, New York, 2Weill Medical College of Cornell University, Obstetrics and Gynecology, New York, New York, 3Weill Medical College of Cornell University, Pathology and Laboratory Medicine, New York, New York OBJECTIVE: To evaluate the antenatal umbilical cord coiling index (aUCI) obtained during the fetal anatomical survey in the second trimester as a predictor of adverse antenatal and perinatal events. STUDY DESIGN: Four hundred and twenty-five consecutive women who had a routine fetal anatomical survey in second trimeseter were evaluated for umbilical cord coiling index. aUCI was correlated with adverse antenatal and perinatal events, such as: small for gestational age (SGA), mode of delivery (interventional vs noninterventional), presence of meconium stained amniotic fluid, presence of non-reassuring fetal status (NRFS) in labor, and low Apgar scores (6 or less) at 1 and 5 minutes. RESULTS: A total of 294 patients had adequate ultrasound images and all antenatal and labor data to meet the study inclusion criteria. The aUCI above 90%ile and below 10%ile were recognized as hyper- and hypocoiled umbilical cords in 10.5% and 9.2% of cases, respectively. Abnormal coiling was significantly associated with SGA neonates at birth (P = .043) and NRFS in labor (P = .007), whereas a trend toward a higher incidence of interventional deliveries and meconium stained amniotic fluid in labor was observed, but statistically nonsignificant (Table). No statistical difference for low Apgar scores between compared groups was noted. CONCLUSION: Abnormal umbilical cord coiling, detected at the fetal ultrasound anatomical survey in the second trimester, can be potentially employed as a predictor of adverse antenatal or perinatal events.

652

Adverse antenatal and perinatal events and abnormal umbilical cord coiling Adverse events

Hypocoiling

Normocoiling

Hypercoiling

Probability

SGA NRFS in labor Interventional delivery Meconium staining Apgar scores

16.1% 29.0% 19.4% 25.8% 3.2%

5.1% 11.0% 8.9% 13.1% 2.5%

14.8% 22.2% 18.5% 22.2% 0%

P = .043 P = .007 P = .16 P = .211 P = .684

PROSPECTIVE ULTRASOUND MEASUREMENT OF PLACENTA USING PANORAMIC VIEW ANNIE OUELLET1, EVA SERRANO2, JEAN MARIE MOUTQUIN3, MARK WALKER4, ANDREE GRUSLIN5, 1Universite de Sherbrooke, Obstetrics & Gynecology, Sherbrooke, Quebec, Canada, 2Universite de Sherbrooke, Obstetrics and Gynecology-Dietitian, Sherbrooke, Quebec, Canada, 3CUSE-Site Fleurimont, OB/GYN, Sherbrooke, Quebec, Canada, 4University of Ottawa, Medicine, Ottawa, Ontario, Canada, 5University of Ottawa, Obstetrics and Gynecology, Ottawa, Ontario, Canada OBJECTIVE: Placental size is related to fetal. Accurate placental size evaluation by conventional ultrasound is limited. Panoramic ultrasound is a new technique that produces large anatomic field structures in a single image. The aim of this study is to find the best placental measurement which correlates with fetal weight throughout normal pregnancy by using this method. STUDY DESIGN: In a cohort of low risk pregnancies, we prospectively measured the maximal/minimal length and maximal thickness of anterior placenta at 20, 28 and 34 weeks of gestation using panoramic view. Fetal weight was also estimated. Correlations between placental measurements and estimated fetal weight at 34 weeks were analysed by the Pearson correlation co-efficient. RESULTS: Fifty-four pregnancies were followed in our ultrasound unit. At 20, 28, and 34 weeks, the mean maximal length of placenta was 13.39 G 1.95 cm, 17.81 G 2.16 cm and 19.29 G 2.14 cm respectively. The mean minimal length was 11.56 G 1.36 cm, 15.01 G 1.87 cm and 16.46 G 2.04 cm and mean maximal thickness was 2.66 G 0.77 cm, 3.12 G 0.89 cm and 3.62 G 0.85 cm for the same periods. Placental thickness offered the weakest correlation with fetal weight throughout pregnancy. The strongest correlation was placental maximal length at 28 weeks with fetal weight at 34 weeks (r = 0.497, P ! .001). Regression analysis yielded the following linear equation: Fetal weight at 34 weeks (g) = (85.574 x Maximal length at 28 weeks) + 1155.7. CONCLUSION: Panoramic ultrasound is a simple technique to quickly measure placenta throughout gestation. The maximal length of placenta at 28 weeks appears to be the best placental measurement to predict fetal weight in pregnancy.

Placental max length (28 wk) vs estimated fetal weight (34 wk)

651

DOES PRIOR CESAREAN DELIVERY AND MATERNAL PARITY INFLUENCE PLACENTAL MIGRATION? MLADEN PREDANIC1, SRIRAM C. PERNI1, CLAUDEL JEAN-PIERRE1, 1Weill Medical College of Cornell University, Obstetrics and Gynecology, New York, New York OBJECTIVE: To assess the association between maternal parity and a history of prior cesarean delivery (CD) in evaluating the persistence of marginal (MPP) and complete placenta previa (CPP) followed by serial ultrasound (US) examination. STUDY DESIGN: In this retrospective study a total of 163 patients were followed by transvaginal ultrasound examination at 28, 32, and 36 weeks of gestation. Low-lying (LLP) and MPP were defined as placentas lying >3.0 cm, and within 0.1-2.9 cm away from the internal cervical os, respectively. A CPP was defined as placenta covering the internal cervical os >0.1 cm. The proportion of patients who had CPP and MPP, with a history of prior CD and parity R2, were compared to patients with LLP and vaginal delivery at 28 to 36 weeks. RESULTS: Although not statistically significant (P = .302), women who had MPP and CPP were more likely to have had a prior CD (total of 7.6%; 3.6% for CPP and 3.2% for MPP) vs. those who had LLP (3.1%) at 28 weeks. At the time of the last US exam at 36 weeks, 4.3% of patients with a prior CD were found to have MPP (1.2%) or CPP (3.1%) compared to 5.5% of patients in the LLP group. This indicated that sufficient placental migration occurred in the group of patient with a MPP to permit vaginal delivery, although had a majority of CD for indications other than placenta previa. In the group of patients with CPP and prior CD, sufficient placental migration occurred only in one patient (1 out 6); therefore, if CPP was observed at 28 weeks (20.0%), it would likely persist at 36 weeks (22.7%). One of 11 patients (9.1%) had a repeat CD for significant bleeding, while the remaining 10 out 11 patients (90.9%) had elective CD for placenta previa. Parity R2 was not associated with significant placental migration in patients with MPP or CPP (P = .857). CONCLUSION: A history of prior CD and maternal multiparity did not influence placental migration from 28 to 36 weeks of gestational age. If the CPP was diagnosed at 28 weeks, it likely persisted until delivery.

653

PERFORMANCE OF THE ‘‘GENETIC’’ SONOGRAM IN THE SECOND AND THIRD TRIMESTER AMY HAIRSTON1, KENNETH MOISE1, HONOR WOLFE1, 1University of North Carolina at Chapel Hill, Obstetrics/Gynecology, Chapel Hill, North Carolina OBJECTIVE: To evaluate the performance of sonographic markers in the detection of aneuploidy in the early and mid second and third trimester. STUDY DESIGN: Fetal/neonatal trisomies (13, 18, 21) were cross-referenced with an ultrasound database to evaluate for the presence of major fetal anomalies and ‘‘soft’’ sonographic markers (nuchal thickening, short humerus or femur, echogenic intracardiac focus, pylectasis, echogenic bowel and CPC). Detection rates were compared using c2 analysis. RESULTS: One hundred and five cases of aneuploidy were analyzed. There was a trend toward less detection of aneuploidy using soft markers in the third trimester (P = .09) and a trend toward increased detection of aneuploidy with major anomalies in the third trimester (P = .11), due to increased detection of congenital heart disease with advancing gestational age. Presence of major anomalies and ‘‘soft’’ sonographic markers by gestational age

15-18 wk 18-24 wk O24 wk

Trisomy 13 (N = 17)

Trisomy 18 (N = 33)

Trisomy 21 (N = 55)

Soft marker

Major anomaly Either

Soft marker

Major anomaly Either

Soft marker

Major anomaly Either

50% (2/4) 90% (10/11) 0% (0/2)

100% (4/4) 100% (11/11) 100% (2/2)

70% (7/10) 93% (14/15) 38% (3/8)

60% (6/10) 73% (11/15) 100% (8/8)

81% (17/21) 69% (16/23) 61% (7/11)

33% (7/21) 30% (7/23) 64% (7/11)

100% (4/4) 100% (11/11) 100% (2/2)

70% (7/10) 100% (15/15) 100% (8/8)

81% (17/21) 78% (18/23) 91% (10/11)

CONCLUSION: There is a nonsignificant trend for a decrease in sonographic detection using ‘‘soft’’ markers and an increased detection using major anomalies with advancing gestational age. Gestational age does not significantly impact the overall performance of the ‘‘genetic’’ sonogram in the detection of trisomies 13, 18, and 21. Fetuses with T21 should undergo sonographic evaluation of the fetal heart in the third trimester to optimize the detection of congenital heart disease.