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Fetal insula to parietal bone distance in the assessment of ventriculomegaly
S154 SMFM Abstracts 535 ULTRASOUND INSERTION LOSS OF THE RAT CERVIX BARBARA L. MCFARLIN1, WILLIAM D. O’BRIEN JR2, MICHAEL L. OELZE2, JAMES F. ZACHARY2, ROSEMARY WHITETRAUT1, 1University of Illinois at Chicago, Maternal Child Nursing, Chicago, Illinois, 2University of Illinois at Urbana-Champaign, Bioacoustics Research Laboratory, Urbana, Illinois OBJECTIVE: The objective was to determine whether the ultrasound insertion loss (IL) measures could detect cervical ripening. Insertion loss is a measure of ultrasound energy loss (attenuation) that results when a sample is inserted into the ultrasound beam relative to when the sample is not present. STUDY DESIGN: Cervices from 15 timed-pregnant (3 rats each @ GAs of 15, 17, 19, 20, & 21) and 3 non-pregnant Sprague-Dawley rats were measured and evaluated for IL over the 40-70 MHz frequency range. RESULTS: Insertion loss was the greatest for the non-pregnant cervix and generally decreased as pregnancy progressed, suggesting marked tissue microstructure changes, particularly at the later GAs.
537 EFFECT OF HYDRATION ON MATERNAL RENAL CALYCEAL DIAMETER IN PREGNANCY JESSICA NYHOLM1, WILLIAM WATSON1, BRIAN BROST1, 1Mayo Clinic College of Medicine, Obstetrics and Gynecology, Rochester, Minnesota OBJECTIVE: There is no published information on how maternal hydration affects renal imaging during pregnancy. The purpose of this study is to evaluate the effect of maternal hydration status on the maternal renal collecting system during the third trimester of pregnancy. STUDY DESIGN: Twenty-five patients with uncomplicated singleton pregnancy were studied during the third trimester (28-40 weeks gestation). Patients with chronic medical illness or a history of kidney disease were excluded. Real time ultrasound of the maternal kidneys was performed after an overnight fast of at least eight hours, one hour after oral hydration with one liter of water, and after voiding. The largest diameter of the renal pelvic-calyceal echolucency was measured at least 3 times, and the results were averaged. Hydronephrosis was defined as a mean pelvic-calyceal diameter of greater than 10 mm. Ultrasound studies were performed by one of the authors. Results were analyzed with the student’s t-test; P ! .05 was considered significant. RESULTS: In the fasting state, prior to hydration, 17 patients (68%) had hydronephrosis; in 7 this was found only on the maternal right side, in 2 only on the left, and 8 were bilateral. After hydration 24 patients (96%) had hydronephrosis; 6 were only the right side, 0 only on the left, and 18 were bilateral. In the maternal right kidney, there was a significant difference found between pre-hydration and post-hydration mean calyceal diameters, 10.5 mm G 11.5 mm and 22.4 mm G 8.6 mm respectively (P!.001). On the left side, significant differences were also noted, with a mean pre-hydration and posthydration measurement of 7.0 mm G 8.9 mm and 13.8 mm G 9.0 mm respectively (P!.01). Pelvic-calyceal measurements were not affected by maternal voiding. CONCLUSION: Maternal hydration status critically influences the maternal pelvic-calyceal diameter in the third trimester of pregnancy. This has significant implications for the timing and interpretation of renal imaging studies in pregnant women.
Insertion Loss by Group CONCLUSION: Our preliminary findings suggest that there are marked IL changes (tissue microstructure changes) associated with cervical ripening and gestational age.
536 FETAL INSULA TO PARIETAL BONE DISTANCE IN THE ASSESSMENT OF VENTRIJYH KAE NIEN2, WESLEY LEE3, CULOMEGALY POOJA MITTAL (F)1, LUIS GONCALVES1, JIMMY ESPINOZA1, BETSY SWOPE1, MARJORIE TREADWELL1, ROBERTO ROMERO2, 1Wayne State University School of Medicine, Department of Obstetrics and Gynecology, Detroit, Michigan, 2Perinatology Research Branch, NICHD, NIH, DHHS, Bethesda, Maryland, 3William Beaumont Hospital, Obstetrics and Gynecology, Royal Oak, Michigan OBJECTIVE: The prenatal diagnosis of neuronal migration disorders is a major challenge. Lissencephaly, a serious disorder uniformly associated with severe mental retardation, can present as simple ventriculomegaly. Recent observations suggest that examination of the insula could be used to assess the degree of development of fetal cerebral cortex sulcation. The aim of this study was to objectively assess whether the development of the insula is impaired in ventriculomegaly which is not associated with migrational disorders. STUDY DESIGN: This cross-sectional study included 203 normal fetuses, and 25 fetuses with an antenatal diagnosis of ventriculomegaly. Multi-planar, three-dimensional ultrasound was used to identify the midpoint of the insula in the axial and coronal planes. The distance from the insula to the inner surface of the parietal bone (IPB) was measured perpendicular to the falx cerebri. A nomogram for this parameter was constructed (ISUOG 2005) and used to evaluate fetuses with ventriculomegaly. Normalized values of the parameter were calculated for affected and unaffected fetuses. Non-parametric statistics were used. RESULTS: 1) Neonatal diagnosis of the 25 cases included: lissencephaly (n=1), aqueductal stenosis (n=4), Arnold-Chiari II malformation (n=4), agenesis of midline structures (n=4), isolated ventriculomegaly (n=6), and transient ventriculomegaly which could not be confirmed with MRI at birth (n=6); 2) Most fetuses with ventriculomegaly (22/25) had an IPB below the estimated mean, regardless of diagnosis; and 3) fetuses with ventriculomegaly had significantly lower normalized IPB than normal fetuses (median: 0.64, range 0.34-1.39 versus median: 0.98, range: 0.78-1.38, respectively, p!0.0001). CONCLUSION: The IPB is affected in fetuses with ventriculomegaly.
538 THE EFFICIENCY OF SECOND TRIMESTER NASAL BONE (NB) HYPOPLASIA AS A MARKER FOR FETAL ANEUPLOIDY IN AN UNSELECTED POPULATION ANTHONY ODIBO1, HARISH M. SEHDEV2, LINDA ODIBO1, LINDA DUNN3, DAVID STAMILIO4, GEORGE MACONES5, 1University of Pennsylvania, Obstetrics and Gynecology, Philadelphia, Pennsylvania, 2Pennsylvania Hospital of the University of Pennsylvania, Obstetrics&Gynecology, Philadelphia, Pennsylvania, 3Chestnut Hill Hospital, Obstetrics and Gynecology, Philadelphia, Pennsylvania, 4University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, 5University of Pennsylvania Medical Center, Obstetrics and Gynecology, Philadelphia, Pennsylvania OBJECTIVE: To evaluate the efficiency of NB hypoplasia in the second trimester as a marker of fetal aneuploidy. STUDY DESIGN: Prospective cohort study of women presenting for fetal anatomic survey between 15 and 22 weeks gestation. NB measurements were obtained from views of the fetal profile and adjusted for gestational age using the biparietal diameter (BPD). NB hypoplasia was defined as a BPD/NB ratio O11. Fetuses or infants with aneuploidy were compared with those without for the presence of NB hypoplasia. Aneuploidy was confirmed either by karyotyping or by newborn examination. Sensitivity, specificity and likelihood ratios (LR): positive (C) and negative (ÿ) for the association between NB and aneuploidy were calculated. RESULTS: Over a 3 year period, 3635 women were evaluated, and NB measurements obtained in 3199 (88%). There were 37 (1%) cases with abnormal karyotypes; 23 with trisomy 21, 8 with trisomy 18 and 6 with other aneuploidy (45XO, 47XXX, Marker chromosomes). The mean NB length was 5.1 mm G1.2 mm. CONCLUSION: In our population, nasal bone hypoplasia in the second trimester was a useful marker for fetal aneuploidy. This marker was more efficient as a marker for trisomy 21 compared with other types of aneuploidy. Karyotype
Sensitivity (%)
Specificity (%)
LRC
LRÿ
Trisomy 21 Trisomy 18 All aneuploidy
14/23 (61) 3/8 (38) 17/37 (46)
2663/3176 (84) 2667/3191 (84) 2652/3162 (84)
3.8 2.4 2.9
0.5 0.7 0.6
537 EFFECT OF HYDRATION ON MATERNAL RENAL CALYCEAL DIAMETER IN PREGNANCY JESSICA NYHOLM1, WILLIAM WATSON1, BRIAN BROST1, 1Mayo Clinic College of Medicine, Obstetrics and Gynecology, Rochester, Minnesota OBJECTIVE: There is no published information on how maternal hydration affects renal imaging during pregnancy. The purpose of this study is to evaluate the effect of maternal hydration status on the maternal renal collecting system during the third trimester of pregnancy. STUDY DESIGN: Twenty-five patients with uncomplicated singleton pregnancy were studied during the third trimester (28-40 weeks gestation). Patients with chronic medical illness or a history of kidney disease were excluded. Real time ultrasound of the maternal kidneys was performed after an overnight fast of at least eight hours, one hour after oral hydration with one liter of water, and after voiding. The largest diameter of the renal pelvic-calyceal echolucency was measured at least 3 times, and the results were averaged. Hydronephrosis was defined as a mean pelvic-calyceal diameter of greater than 10 mm. Ultrasound studies were performed by one of the authors. Results were analyzed with the student’s t-test; P ! .05 was considered significant. RESULTS: In the fasting state, prior to hydration, 17 patients (68%) had hydronephrosis; in 7 this was found only on the maternal right side, in 2 only on the left, and 8 were bilateral. After hydration 24 patients (96%) had hydronephrosis; 6 were only the right side, 0 only on the left, and 18 were bilateral. In the maternal right kidney, there was a significant difference found between pre-hydration and post-hydration mean calyceal diameters, 10.5 mm G 11.5 mm and 22.4 mm G 8.6 mm respectively (P!.001). On the left side, significant differences were also noted, with a mean pre-hydration and posthydration measurement of 7.0 mm G 8.9 mm and 13.8 mm G 9.0 mm respectively (P!.01). Pelvic-calyceal measurements were not affected by maternal voiding. CONCLUSION: Maternal hydration status critically influences the maternal pelvic-calyceal diameter in the third trimester of pregnancy. This has significant implications for the timing and interpretation of renal imaging studies in pregnant women.
Insertion Loss by Group CONCLUSION: Our preliminary findings suggest that there are marked IL changes (tissue microstructure changes) associated with cervical ripening and gestational age.
536 FETAL INSULA TO PARIETAL BONE DISTANCE IN THE ASSESSMENT OF VENTRIJYH KAE NIEN2, WESLEY LEE3, CULOMEGALY POOJA MITTAL (F)1, LUIS GONCALVES1, JIMMY ESPINOZA1, BETSY SWOPE1, MARJORIE TREADWELL1, ROBERTO ROMERO2, 1Wayne State University School of Medicine, Department of Obstetrics and Gynecology, Detroit, Michigan, 2Perinatology Research Branch, NICHD, NIH, DHHS, Bethesda, Maryland, 3William Beaumont Hospital, Obstetrics and Gynecology, Royal Oak, Michigan OBJECTIVE: The prenatal diagnosis of neuronal migration disorders is a major challenge. Lissencephaly, a serious disorder uniformly associated with severe mental retardation, can present as simple ventriculomegaly. Recent observations suggest that examination of the insula could be used to assess the degree of development of fetal cerebral cortex sulcation. The aim of this study was to objectively assess whether the development of the insula is impaired in ventriculomegaly which is not associated with migrational disorders. STUDY DESIGN: This cross-sectional study included 203 normal fetuses, and 25 fetuses with an antenatal diagnosis of ventriculomegaly. Multi-planar, three-dimensional ultrasound was used to identify the midpoint of the insula in the axial and coronal planes. The distance from the insula to the inner surface of the parietal bone (IPB) was measured perpendicular to the falx cerebri. A nomogram for this parameter was constructed (ISUOG 2005) and used to evaluate fetuses with ventriculomegaly. Normalized values of the parameter were calculated for affected and unaffected fetuses. Non-parametric statistics were used. RESULTS: 1) Neonatal diagnosis of the 25 cases included: lissencephaly (n=1), aqueductal stenosis (n=4), Arnold-Chiari II malformation (n=4), agenesis of midline structures (n=4), isolated ventriculomegaly (n=6), and transient ventriculomegaly which could not be confirmed with MRI at birth (n=6); 2) Most fetuses with ventriculomegaly (22/25) had an IPB below the estimated mean, regardless of diagnosis; and 3) fetuses with ventriculomegaly had significantly lower normalized IPB than normal fetuses (median: 0.64, range 0.34-1.39 versus median: 0.98, range: 0.78-1.38, respectively, p!0.0001). CONCLUSION: The IPB is affected in fetuses with ventriculomegaly.
538 THE EFFICIENCY OF SECOND TRIMESTER NASAL BONE (NB) HYPOPLASIA AS A MARKER FOR FETAL ANEUPLOIDY IN AN UNSELECTED POPULATION ANTHONY ODIBO1, HARISH M. SEHDEV2, LINDA ODIBO1, LINDA DUNN3, DAVID STAMILIO4, GEORGE MACONES5, 1University of Pennsylvania, Obstetrics and Gynecology, Philadelphia, Pennsylvania, 2Pennsylvania Hospital of the University of Pennsylvania, Obstetrics&Gynecology, Philadelphia, Pennsylvania, 3Chestnut Hill Hospital, Obstetrics and Gynecology, Philadelphia, Pennsylvania, 4University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, 5University of Pennsylvania Medical Center, Obstetrics and Gynecology, Philadelphia, Pennsylvania OBJECTIVE: To evaluate the efficiency of NB hypoplasia in the second trimester as a marker of fetal aneuploidy. STUDY DESIGN: Prospective cohort study of women presenting for fetal anatomic survey between 15 and 22 weeks gestation. NB measurements were obtained from views of the fetal profile and adjusted for gestational age using the biparietal diameter (BPD). NB hypoplasia was defined as a BPD/NB ratio O11. Fetuses or infants with aneuploidy were compared with those without for the presence of NB hypoplasia. Aneuploidy was confirmed either by karyotyping or by newborn examination. Sensitivity, specificity and likelihood ratios (LR): positive (C) and negative (ÿ) for the association between NB and aneuploidy were calculated. RESULTS: Over a 3 year period, 3635 women were evaluated, and NB measurements obtained in 3199 (88%). There were 37 (1%) cases with abnormal karyotypes; 23 with trisomy 21, 8 with trisomy 18 and 6 with other aneuploidy (45XO, 47XXX, Marker chromosomes). The mean NB length was 5.1 mm G1.2 mm. CONCLUSION: In our population, nasal bone hypoplasia in the second trimester was a useful marker for fetal aneuploidy. This marker was more efficient as a marker for trisomy 21 compared with other types of aneuploidy. Karyotype
Sensitivity (%)
Specificity (%)
LRC
LRÿ
Trisomy 21 Trisomy 18 All aneuploidy
14/23 (61) 3/8 (38) 17/37 (46)
2663/3176 (84) 2667/3191 (84) 2652/3162 (84)
3.8 2.4 2.9
0.5 0.7 0.6