- Email: [email protected]
374: Does advanced maternal age (AMA) alone increase the risk of structural fetal anomalies?
Poster Session II
Clinical Obstetrics, Diabetes, Labor, Medical-Surgical-Disease, Physiology/Endocrinology, Prematurity
www.AJOG.org
373 Expectant management of monochorionic diamniotic twins with selective intrauterine growth restriction Karen Flood1, Amanda Ali3, Fionnuala Breathnach1, Fionnuala Mc Auliffe2, Michael Geary3, Sean Daly5, John Higgins9, Alison Fogarty6, John Morrison7, Gerard Burke8, Shane Higgins4, Patrick Dicker1, Elizabeth Tully1, Stephen Carroll4, Fergal Malone1 1 Royal College of Surgeons in Ireland, Obstetrics and Gynecology, Dublin, Ireland, 2University College Dublin School of Medicine and Medical Science, University College Dublin., Obstetrics and Gynecology, Dublin, Ireland, 3 Rotunda Hospital, Obstetrics and Gyneology, Dublin, Ireland, 4National Maternity Hospital, Obstetrics and Gynecology, Dublin, Ireland, 5Coombe Womens and Infants’ University Hospital, Obstetrics and Gynecology, Dublin, Ireland, 6Royal Victoria Maternity Hospital, Obstetrics and Gynecology, Belfast, Ireland, 7National University of Ireland, Galway, Obstetrics and Gynecology, Galway, Ireland, 8University Hospital Limerick, Obstetrics and Gynecology, Limerick, Ireland, 9Cork University Maternity Hospital, Obstetrics and Gynecology, Cork, Ireland
372 Ventricular functional responses to altered loading conditions in the fetal heart: a sheep study with acute ascending aorta occlusion Heikki Huhta1, Juha Räsänen5, Juulia Junno1, Tiina Erkinaro2, Mervi Haapsamo1, Roger Hohimer3, Lowell Davis3, Ganesh Acharya4 1 Oulu University Hospital, Obstetrics and Gynecology, Oulu, Finland, 2Oulu University Hospital, Anesthesiology, Oulu, Finland, 3Oregon Health and Science University, Obstetrics and Gynecology, Portland, OR, 4University Hospital of Northern Norway, Obstetrics and Gynecology, Tromso, Norway, 5 Kuopio University Hospital, Obstetrics and Gynecology, Kuopio, Finland
OBJECTIVE: We hypothesized that during acute fetal ascending aorta (AA) occlusion (AAO) right ventricular (RV) performance is improved by acutely increased preload, while an increase in left ventricular (LV) afterload has a negative impact on its function. STUDY DESIGN: Nine ewes underwent surgery at 115-135 gestational days (term 145 days) for the placement of a vascular occluder around fetal AA. Fetal carotid artery and jugular vein were cannulated. After a 4-day recovery, fetal heart rate (FHR), right (RVSV) and left (LVSV) ventricular stroke volumes were measured by ultrasonography. Using pulsed-wave tissue Doppler imaging, RV and LV lateral wall longitudinal myocardial velocities were obtained at the level of tricuspid and mitral valve annuli. Ventricular systolic function was assessed by measuring isovolumic contraction velocity (IVCV) and its acceleration (load-independent index of ventricular contractility) and diastolic function by measuring isovolumic relaxation velocity (IVRV) and its deceleration. All the measurements were obtained at baseline, 15 and 60 minutes after AAO, and 15 minutes after release of AAO. RESULTS: All the data are presented as means (SD).* p⬍0.05, compared with baseline. CONCLUSION: Acute AAO in fetal sheep increased RVSV and decreased LVSV. The rise in RV preload improved RV contractility, however signs of diastolic dysfunction were observed. Left ventricle showed abnormalities in systolic and diastolic function immediately following an acute increase in afterload. These findings suggest that fetal LV could be more sensitive to acutely altered loading conditions than RV.
S164
OBJECTIVE: The optimal timing of delivery for uncomplicated MCDA twins remains controversial. Selective intra-uterine growth restriction (sIUGR) adds further complexity to MCDA twins due to the further increased risk of intrauterine fetal death (IUFD) and the potential devastating effects on the co-twin survivor. We sought to evaluate the outcomes in a cohort of MCDA twins with sIUGR managed expectantly. STUDY DESIGN: This prospective multicenter cohort study included 1,028 unselected twin pairs recruited over a 2 year period in eight tertiary referral perinatal centers in Ireland. Monochorionic twins underwent fortnightly ultrasonographic surveillance from 16 weeks. The defining criteria for sIUGR was an estimated fetal weight less than the 10th centile in one twin with an appropriately grown co-twin in the absence of twin-totwin transfusion syndrome, aneuploidy or major structural malformations. Details of the prenatal course, delivery timing and perinatal outcomes were recorded. RESULTS: Outcome data were recorded for 100% of the 1,001 twin pairs that completed the study (n⫽200 monochorionic). Five percent (n⫽10) of the MCDA twin pregnancies were diagnosed with sIUGR at a median gestation of 30 weeks (range 26 - 35 weeks). Absent or reversed end-diastolic flow in the UA Doppler was identified in two of these 10 cases. The median time interval from diagnosis to delivery was 36.8 days (range 3 - 66 days) at a mean gestation of 34.2 weeks (range 26-37.9 weeks). 70% of the affected twins were admitted to the NICU with a mean stay of 19 days. There were no perinatal mortalities. CONCLUSION: Our findings demonstrated excellent outcomes for our MCDA twins complicated by sIUGR. There were no pregnancies complicated by single IUFD and in turn there was no morbidity conferred to the appropriately grown co-twin. Close ultrasonographic surveillance with regular Doppler evaluation was essential and allowed continuation of affected pregnancies to a late gestational age, thereby optimizing outcome for both twins.
374 Does advanced maternal age (AMA) alone increase the risk of structural fetal anomalies? Katharine Wenstrom1, Barbara O’Brien1, Julie Johnson1 1 Brown Alpert School of Medicine, Obstetrics and Gynecology, Providence, RI
OBJECTIVE: Although data suggest that AMA alone is a risk factor for structural fetal defects, especially cardiac defects, published studies have not determined if study subjects had additional risk factors such as diabetes, medication use, multiple gestation, and others. We sought to detemine whether AMA alone increases the risk of structural fetal defects or if other risk factors could be contributory. STUDY DESIGN: With IRB approval, we retrieved all level 2 ultrasound exams performed on women age ⱖ 35 from 1/1/08 to 12/31/11 at our tertiary center. After excluding all aneuploidies, cases were categorized as “AMA Only” if there were no other indications for the exam, or “AMA Plus” if there were additional indications such as diabetes,
American Journal of Obstetrics & Gynecology Supplement to JANUARY 2013
www.AJOG.org
Clinical Obstetrics, Diabetes, Labor, Medical-Surgical-Disease, Physiology/Endocrinology, Prematurity
medication exposure, etc. All ultrasound exams were reviewed for the presence of either structural fetal defects or ultrasound markers of aneuploidy only. We also did a subanalysis of the incidence of fetal cardiac defects in both AMA groups and in all level 2 ultrasound exams performed on women age ⱕ 34 (n⫽8300) during the same time period. RESULTS: The incidence of structural fetal anomalies was significantly higher in the AMA Plus Group (P⫽0.0001; Table).The most common defects in the AMA Plus group were renal anomalies (n⫽ 48; 1.3%), cardiac defects (n⫽ 24; 0.6%) and NTDs (n⫽15; 0.4%). The only fetal anomaly in the AMA Only group was a cardiac defect (0.3%). The incidence of cardiac defects in the AMA groups (25/336; 0.65%) was similar to that in women ⱕ 34 years (61/8300; 0.7%); P⫽ 0.69. CONCLUSION: Structural fetal defects in the fetuses of women age ⱖ 35 do not seem to be related to maternal age alone, but rather are associated with other risk factors such as diabetes, medication use, and others.The incidence of cardiac defects in women age ⱖ 35 is not different from that in women age ⱕ 34 who have the same risk factors. Women ⱖ 35 without other risk factors should be reassured that, excluding aneuploidy, their offspring are not at increased risk of birth defects.
Poster Session II
scanning time was 29.5⫾10.1min vs. 30.7⫾7.6min (p⫽NS), in periods II and III, respectively. CONCLUSION: Stepwise integration of the ISUOG fetal echocardiography guidelines increases detection rates of cardiac anomalies during routine anatomic surveys without prolongation of scanning time.
Level 2 ultrasound findings
375 Step-wise integration of fetal echocardiography into the routine anatomic survey: impact on detection rates of cardiac malformations Krishna Singh1, Steve Rad1, Tania Esakoff2, Sarah Beauchamp1, Artemis Alanakian1, Cynthia McMullen1, Siegfried Rotmensch2 1 Cedars-Sinai Medical Center, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Los Angeles, CA, 2David Geffen School of Medicine at UCLA, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Cedars-Sinai Medical Center, Los Angeles, CA
OBJECTIVE: Comprehensive examination of the fetal heart by echocardiography is time-consuming, yet yields higher anomaly detection rates. We examined the impact of a step-wise integration of the ISUOG echocardiography guidelines (ISUOG-E-G) into the routine fetal anatomic survey on time commitment and cardiac anomaly detection. STUDY DESIGN: ISUOG-E-G (2008) were gradually integrated into our routine scanning protocol (18-24 wks) as of 12/08. Anomaly detection rates and scanning performance were compared between period I (1/07 to 12/08; “baseline”); period II (“training”; 1/09 to 12/10), and period III (“integration”; 1/11-7/12). Venous-atrial, atrio-ventricular, ventriculo-arterial connections, as well as atrial- ventricular-septal morphology, and cardiac axis were examined by visualization of ventricular outflow tracts (OT), “three-vessel and trachea (3VT) view” or sagittal aortic and ductal arches, and short axis views. All pediatric cardiology referrals were reviewed for significant structural anomalies and validated by neonatal examinations when feasible. Arrhythmias and second opinion requests from external sources were excluded. Images from 100 randomly sampled patients in periods II and III, respectively, were reviewed to determine which cardiac planes were examined and scan time. Student t, Fisher exact and Chi-square tests were used for statistical evaluation. RESULTS: Cardiac anomaly detection rates increased significantly from period I to III from 3.4 to 7.1/1000 scans (p⬍0.05). Successful visualization of echocardiographic planes and completion of comprehensive echocardiography also increased over time (Figure). Mean
376 The “three vessel and trachea view” as part of the routine fetal anatomic survey: analysis of success rates, technical quality, and time requirements Krishna Singh1, Daniele Feldman1, Steve Rad1, Carolyn Burk1, Jennifer Peterman1, Tania Esakoff2, Siegfried Rotmensch2 1 Cedars-Sinai Medical Center, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Los Angeles, CA, 2David Geffen School of Medicine at UCLA, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Cedars-Sinai Medical Center, Los Angeles, CA
OBJECTIVE: Visualization of the cardiac outflow tracts and great arteries is time consuming, yet substantially improves the detection rate of cardiac malformations. The “three vessel and trachea (3VT) view” (Yagel et al; 2002) is technically easy to obtain, and visualizes the number, dimensions, location, and course of the upper mediastinal vessels. We evaluated the success rate, technical quality, and time requirement to obtain the 3VT view as part of the routine fetal anatomic survey. STUDY DESIGN: We routinely obtain the 3VT view as part of the fetal anatomic survey. After evaluation of the 4 chamber (4CH) view, the transducer is moved cephalad into the upper mediastinum, while maintaining a transverse plane orientation. Archived images of 340 normal scans between 1/12 and 7/12 were retrospectively reviewed. Time-intervals between visualization of the 4CH and 3VT views were measured in seconds, and visualization of the trachea was assessed as being present or absent. The position of the fetal spine in the 3VT view was recorded and assigned to 1 of 4 quadrants (0-90°, 90-180°, 180270°, and 270-360° of circle). Fischer‘s exact test was used for statistical analysis. RESULTS: Visualization of the 3VT view was feasible in 95% of cases (n⫽321/340). In 23% of cases, the 3VT view was visualized before the 4CH view. In 72%, 83% and 91% of cases, the 3VT view was visualized within 1, 2 and 5 min (average 23⫾14 sec, 30.6⫾24.3 sec and 43.8⫾52 sec, respectively.) In all cases in which acquisition of the 3VT view exceeded 1 min, other heart views were obtained in the interim. Visualization of the trachea was feasible in 91.6% of 3VT views. Failure to obtain the 3VT view or visualize the trachea was not associated with spine position (p⫽NS).
Supplement to JANUARY 2013 American Journal of Obstetrics & Gynecology
S165
Clinical Obstetrics, Diabetes, Labor, Medical-Surgical-Disease, Physiology/Endocrinology, Prematurity
www.AJOG.org
373 Expectant management of monochorionic diamniotic twins with selective intrauterine growth restriction Karen Flood1, Amanda Ali3, Fionnuala Breathnach1, Fionnuala Mc Auliffe2, Michael Geary3, Sean Daly5, John Higgins9, Alison Fogarty6, John Morrison7, Gerard Burke8, Shane Higgins4, Patrick Dicker1, Elizabeth Tully1, Stephen Carroll4, Fergal Malone1 1 Royal College of Surgeons in Ireland, Obstetrics and Gynecology, Dublin, Ireland, 2University College Dublin School of Medicine and Medical Science, University College Dublin., Obstetrics and Gynecology, Dublin, Ireland, 3 Rotunda Hospital, Obstetrics and Gyneology, Dublin, Ireland, 4National Maternity Hospital, Obstetrics and Gynecology, Dublin, Ireland, 5Coombe Womens and Infants’ University Hospital, Obstetrics and Gynecology, Dublin, Ireland, 6Royal Victoria Maternity Hospital, Obstetrics and Gynecology, Belfast, Ireland, 7National University of Ireland, Galway, Obstetrics and Gynecology, Galway, Ireland, 8University Hospital Limerick, Obstetrics and Gynecology, Limerick, Ireland, 9Cork University Maternity Hospital, Obstetrics and Gynecology, Cork, Ireland
372 Ventricular functional responses to altered loading conditions in the fetal heart: a sheep study with acute ascending aorta occlusion Heikki Huhta1, Juha Räsänen5, Juulia Junno1, Tiina Erkinaro2, Mervi Haapsamo1, Roger Hohimer3, Lowell Davis3, Ganesh Acharya4 1 Oulu University Hospital, Obstetrics and Gynecology, Oulu, Finland, 2Oulu University Hospital, Anesthesiology, Oulu, Finland, 3Oregon Health and Science University, Obstetrics and Gynecology, Portland, OR, 4University Hospital of Northern Norway, Obstetrics and Gynecology, Tromso, Norway, 5 Kuopio University Hospital, Obstetrics and Gynecology, Kuopio, Finland
OBJECTIVE: We hypothesized that during acute fetal ascending aorta (AA) occlusion (AAO) right ventricular (RV) performance is improved by acutely increased preload, while an increase in left ventricular (LV) afterload has a negative impact on its function. STUDY DESIGN: Nine ewes underwent surgery at 115-135 gestational days (term 145 days) for the placement of a vascular occluder around fetal AA. Fetal carotid artery and jugular vein were cannulated. After a 4-day recovery, fetal heart rate (FHR), right (RVSV) and left (LVSV) ventricular stroke volumes were measured by ultrasonography. Using pulsed-wave tissue Doppler imaging, RV and LV lateral wall longitudinal myocardial velocities were obtained at the level of tricuspid and mitral valve annuli. Ventricular systolic function was assessed by measuring isovolumic contraction velocity (IVCV) and its acceleration (load-independent index of ventricular contractility) and diastolic function by measuring isovolumic relaxation velocity (IVRV) and its deceleration. All the measurements were obtained at baseline, 15 and 60 minutes after AAO, and 15 minutes after release of AAO. RESULTS: All the data are presented as means (SD).* p⬍0.05, compared with baseline. CONCLUSION: Acute AAO in fetal sheep increased RVSV and decreased LVSV. The rise in RV preload improved RV contractility, however signs of diastolic dysfunction were observed. Left ventricle showed abnormalities in systolic and diastolic function immediately following an acute increase in afterload. These findings suggest that fetal LV could be more sensitive to acutely altered loading conditions than RV.
S164
OBJECTIVE: The optimal timing of delivery for uncomplicated MCDA twins remains controversial. Selective intra-uterine growth restriction (sIUGR) adds further complexity to MCDA twins due to the further increased risk of intrauterine fetal death (IUFD) and the potential devastating effects on the co-twin survivor. We sought to evaluate the outcomes in a cohort of MCDA twins with sIUGR managed expectantly. STUDY DESIGN: This prospective multicenter cohort study included 1,028 unselected twin pairs recruited over a 2 year period in eight tertiary referral perinatal centers in Ireland. Monochorionic twins underwent fortnightly ultrasonographic surveillance from 16 weeks. The defining criteria for sIUGR was an estimated fetal weight less than the 10th centile in one twin with an appropriately grown co-twin in the absence of twin-totwin transfusion syndrome, aneuploidy or major structural malformations. Details of the prenatal course, delivery timing and perinatal outcomes were recorded. RESULTS: Outcome data were recorded for 100% of the 1,001 twin pairs that completed the study (n⫽200 monochorionic). Five percent (n⫽10) of the MCDA twin pregnancies were diagnosed with sIUGR at a median gestation of 30 weeks (range 26 - 35 weeks). Absent or reversed end-diastolic flow in the UA Doppler was identified in two of these 10 cases. The median time interval from diagnosis to delivery was 36.8 days (range 3 - 66 days) at a mean gestation of 34.2 weeks (range 26-37.9 weeks). 70% of the affected twins were admitted to the NICU with a mean stay of 19 days. There were no perinatal mortalities. CONCLUSION: Our findings demonstrated excellent outcomes for our MCDA twins complicated by sIUGR. There were no pregnancies complicated by single IUFD and in turn there was no morbidity conferred to the appropriately grown co-twin. Close ultrasonographic surveillance with regular Doppler evaluation was essential and allowed continuation of affected pregnancies to a late gestational age, thereby optimizing outcome for both twins.
374 Does advanced maternal age (AMA) alone increase the risk of structural fetal anomalies? Katharine Wenstrom1, Barbara O’Brien1, Julie Johnson1 1 Brown Alpert School of Medicine, Obstetrics and Gynecology, Providence, RI
OBJECTIVE: Although data suggest that AMA alone is a risk factor for structural fetal defects, especially cardiac defects, published studies have not determined if study subjects had additional risk factors such as diabetes, medication use, multiple gestation, and others. We sought to detemine whether AMA alone increases the risk of structural fetal defects or if other risk factors could be contributory. STUDY DESIGN: With IRB approval, we retrieved all level 2 ultrasound exams performed on women age ⱖ 35 from 1/1/08 to 12/31/11 at our tertiary center. After excluding all aneuploidies, cases were categorized as “AMA Only” if there were no other indications for the exam, or “AMA Plus” if there were additional indications such as diabetes,
American Journal of Obstetrics & Gynecology Supplement to JANUARY 2013
www.AJOG.org
Clinical Obstetrics, Diabetes, Labor, Medical-Surgical-Disease, Physiology/Endocrinology, Prematurity
medication exposure, etc. All ultrasound exams were reviewed for the presence of either structural fetal defects or ultrasound markers of aneuploidy only. We also did a subanalysis of the incidence of fetal cardiac defects in both AMA groups and in all level 2 ultrasound exams performed on women age ⱕ 34 (n⫽8300) during the same time period. RESULTS: The incidence of structural fetal anomalies was significantly higher in the AMA Plus Group (P⫽0.0001; Table).The most common defects in the AMA Plus group were renal anomalies (n⫽ 48; 1.3%), cardiac defects (n⫽ 24; 0.6%) and NTDs (n⫽15; 0.4%). The only fetal anomaly in the AMA Only group was a cardiac defect (0.3%). The incidence of cardiac defects in the AMA groups (25/336; 0.65%) was similar to that in women ⱕ 34 years (61/8300; 0.7%); P⫽ 0.69. CONCLUSION: Structural fetal defects in the fetuses of women age ⱖ 35 do not seem to be related to maternal age alone, but rather are associated with other risk factors such as diabetes, medication use, and others.The incidence of cardiac defects in women age ⱖ 35 is not different from that in women age ⱕ 34 who have the same risk factors. Women ⱖ 35 without other risk factors should be reassured that, excluding aneuploidy, their offspring are not at increased risk of birth defects.
Poster Session II
scanning time was 29.5⫾10.1min vs. 30.7⫾7.6min (p⫽NS), in periods II and III, respectively. CONCLUSION: Stepwise integration of the ISUOG fetal echocardiography guidelines increases detection rates of cardiac anomalies during routine anatomic surveys without prolongation of scanning time.
Level 2 ultrasound findings
375 Step-wise integration of fetal echocardiography into the routine anatomic survey: impact on detection rates of cardiac malformations Krishna Singh1, Steve Rad1, Tania Esakoff2, Sarah Beauchamp1, Artemis Alanakian1, Cynthia McMullen1, Siegfried Rotmensch2 1 Cedars-Sinai Medical Center, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Los Angeles, CA, 2David Geffen School of Medicine at UCLA, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Cedars-Sinai Medical Center, Los Angeles, CA
OBJECTIVE: Comprehensive examination of the fetal heart by echocardiography is time-consuming, yet yields higher anomaly detection rates. We examined the impact of a step-wise integration of the ISUOG echocardiography guidelines (ISUOG-E-G) into the routine fetal anatomic survey on time commitment and cardiac anomaly detection. STUDY DESIGN: ISUOG-E-G (2008) were gradually integrated into our routine scanning protocol (18-24 wks) as of 12/08. Anomaly detection rates and scanning performance were compared between period I (1/07 to 12/08; “baseline”); period II (“training”; 1/09 to 12/10), and period III (“integration”; 1/11-7/12). Venous-atrial, atrio-ventricular, ventriculo-arterial connections, as well as atrial- ventricular-septal morphology, and cardiac axis were examined by visualization of ventricular outflow tracts (OT), “three-vessel and trachea (3VT) view” or sagittal aortic and ductal arches, and short axis views. All pediatric cardiology referrals were reviewed for significant structural anomalies and validated by neonatal examinations when feasible. Arrhythmias and second opinion requests from external sources were excluded. Images from 100 randomly sampled patients in periods II and III, respectively, were reviewed to determine which cardiac planes were examined and scan time. Student t, Fisher exact and Chi-square tests were used for statistical evaluation. RESULTS: Cardiac anomaly detection rates increased significantly from period I to III from 3.4 to 7.1/1000 scans (p⬍0.05). Successful visualization of echocardiographic planes and completion of comprehensive echocardiography also increased over time (Figure). Mean
376 The “three vessel and trachea view” as part of the routine fetal anatomic survey: analysis of success rates, technical quality, and time requirements Krishna Singh1, Daniele Feldman1, Steve Rad1, Carolyn Burk1, Jennifer Peterman1, Tania Esakoff2, Siegfried Rotmensch2 1 Cedars-Sinai Medical Center, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Los Angeles, CA, 2David Geffen School of Medicine at UCLA, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Cedars-Sinai Medical Center, Los Angeles, CA
OBJECTIVE: Visualization of the cardiac outflow tracts and great arteries is time consuming, yet substantially improves the detection rate of cardiac malformations. The “three vessel and trachea (3VT) view” (Yagel et al; 2002) is technically easy to obtain, and visualizes the number, dimensions, location, and course of the upper mediastinal vessels. We evaluated the success rate, technical quality, and time requirement to obtain the 3VT view as part of the routine fetal anatomic survey. STUDY DESIGN: We routinely obtain the 3VT view as part of the fetal anatomic survey. After evaluation of the 4 chamber (4CH) view, the transducer is moved cephalad into the upper mediastinum, while maintaining a transverse plane orientation. Archived images of 340 normal scans between 1/12 and 7/12 were retrospectively reviewed. Time-intervals between visualization of the 4CH and 3VT views were measured in seconds, and visualization of the trachea was assessed as being present or absent. The position of the fetal spine in the 3VT view was recorded and assigned to 1 of 4 quadrants (0-90°, 90-180°, 180270°, and 270-360° of circle). Fischer‘s exact test was used for statistical analysis. RESULTS: Visualization of the 3VT view was feasible in 95% of cases (n⫽321/340). In 23% of cases, the 3VT view was visualized before the 4CH view. In 72%, 83% and 91% of cases, the 3VT view was visualized within 1, 2 and 5 min (average 23⫾14 sec, 30.6⫾24.3 sec and 43.8⫾52 sec, respectively.) In all cases in which acquisition of the 3VT view exceeded 1 min, other heart views were obtained in the interim. Visualization of the trachea was feasible in 91.6% of 3VT views. Failure to obtain the 3VT view or visualize the trachea was not associated with spine position (p⫽NS).
Supplement to JANUARY 2013 American Journal of Obstetrics & Gynecology
S165