- Email: [email protected]
563: Estimated placental volume (EPV): a novel predictor of small for gestational age birth weight (SGA)
Poster Session III
ajog.org RESULTS: 8005 women had NT screening in at least 2 consecutive pregnancies in our unit. 93 women with known aneuploidy in either pregnancy were excluded. Of the 7912 women included, there was a significant correlation between NT MoM in the 1st and 2nd pregnancy (r¼.126, p<.001). Women with an abnormal NT in the 1st pregnancy were significantly more likely to have an abnormal NT in the subsequent pregnancy (p<.001). When stratifying the data according to ethnicity, a significant correlation between NT in consecutive pregnancies was still present in White, Asian and African American populations. CONCLUSION: There was a significant correlation for NT between consecutive pregnancies in individual patients. Women having an abnormal NT in one euploid pregnancy, are more likely to have an abnormal NT in a subsequent pregnancy. This suggests that intrinsic factors contribute to NT measurements, and prior NT measurements could be considered in the interpretation of NT measurements in multiparous women.
Distribution of NT MoM NT MoM <95%ile NT MoM >95%ile 1st Pregnancy
7559 (95.5%)
353(4.5%)
2nd Pregnancy 7561 (95.6%)
351 (4.4%)
563 Estimated placental volume (EPV): a novel predictor of small for gestational age birth weight (SGA) Katherine H. Campbell1, France Galerneau1, Harvey Kliman1, Radek K. Bukowski1 1
Yale University, New Haven, CT
OBJECTIVE: Traditionally SGA is predicted and further pregnancy
management defined on the ultrasound generated estimated fetal weight (EFW). The aim of this study was to evaluate predictive ability of simple 2D ultrasound EPV to predict SGA birth weight. STUDY DESIGN: In a prospective cohort study of 371 pregnant women the EPV and EFW of ongoing singleton gestations was calculated. From this, we identified 77 women with EPV and EFW measurements obtained between 15 weeks 4 days and 23 weeks 6 days with birth weights available for assessment. EPV was measured using a validated mathematical model (Azpurua et al, 2010) that uses the maximal width, height, and thickness of the placenta obtained at the time of obstetrical ultrasound. Both EPV and EFW percentiles for gestational age were calculated and used for analysis. SGA was defined as birth weight < 10th percentile for gestational age. The abilities of EPV or EFW to predict SGA were evaluated using logistic regression, area under Receiver Operating Characteristics Curve (aROC), Integrated Discrimination Improvement (IDI) and Net Reclassification Improvement (NRI). RESULTS: EPV unlike EFW was associated with significant reduction in the risk of SGA at the rate of 4% reduction for each percentile increase in EPV (OR [95% CI], 0.96 [0.93-0.99], p¼0.004). EPV was also associated with a trend in increase in aROC comparing to EFW (78% vs 62%, p¼0.059). There was no evidence of significant miscalibration of either EPV or EFW models predicting SGA. EPV was associated with a significant and strong improvement in reclassification when considered in addition to EFW (IDI¼0.13, p¼0.0004 and NRI¼1.15, p¼0.0001. The 115% improvement in NRI was composed of 84% improvement of true positives and 31% improvement in true negatives.
CONCLUSION: EPV provides a new effective predictor of SGA which significantly improves predictive ability of traditionally used EFW. Future studies should concentrate on external validation and identification of optimal cut-offs for the clinical use.
564 A sonographic protocol of standardized physics settings to improve detection of placenta accreta Barbora Mrazek-Pugh1, Amanda Yeaton-Massey2, Jane Chueh2, Deirdre Lyell2 1
Lucile Packard Children’s Hospital at Stanford, Palo Alto, CA, 2Department of Obstetrics & Gynecology, Stanford University School of Medicine, Stanford, CA
OBJECTIVE: The reported accuracy of ultrasound in the detection of
placenta accreta is variable yet such accuracy is critical for delivery planning. Assessment of several sonographic markers of accreta have been described to improve accuracy, but the importance of ultrasound machine settings in accurately assessing these markers is often not considered. We sought to investigate whether the use of a sonographic protocol with standardized ultrasound physics settings could improve the detection of placenta accreta. STUDY DESIGN: Women with suspected placenta accreta were assessed by routine ultrasound by MFM specialists and Pediatric Radiologists from 2011-2013. In 2014, all sonographers and attending physicians were trained in the new standardized physics settings (Table). The lead sonographer (BMP) performed a quality review to ensure universal protocol adherence. Scans that deviated from the protocol were reviewed with the performing team and the patient was rescanned. The primary outcome was accurate sonographic prediction of placenta accreta as determined by clinical and pathologic measures. Positive predictive value (PPV) and negative predictive value (NPV) were calculated. RESULTS: 63 women were evaluated; 38 using the prior standard sonographic assessment and 25 using the new protocol. The PPV and NPV for accurate sonographic assessment of accreta were 75% and 71% prior to implementation of the new protocol, and 100% and 100% respectively after implementation. CONCLUSION: The use of standardized physics settings in the evaluation of suspected placenta accreta significantly improved the PPV and NPV of sonographic detection of accreta. By standardizing the settings of 2D, color Doppler and pulse wave Doppler, and by performing a quality review to ensure these settings were used, one can increase the accuracy of sonographic detection of placenta accreta, allowing for appropriate delivery planning.
Supplement to JANUARY 2016 American Journal of Obstetrics & Gynecology
S303
ajog.org RESULTS: 8005 women had NT screening in at least 2 consecutive pregnancies in our unit. 93 women with known aneuploidy in either pregnancy were excluded. Of the 7912 women included, there was a significant correlation between NT MoM in the 1st and 2nd pregnancy (r¼.126, p<.001). Women with an abnormal NT in the 1st pregnancy were significantly more likely to have an abnormal NT in the subsequent pregnancy (p<.001). When stratifying the data according to ethnicity, a significant correlation between NT in consecutive pregnancies was still present in White, Asian and African American populations. CONCLUSION: There was a significant correlation for NT between consecutive pregnancies in individual patients. Women having an abnormal NT in one euploid pregnancy, are more likely to have an abnormal NT in a subsequent pregnancy. This suggests that intrinsic factors contribute to NT measurements, and prior NT measurements could be considered in the interpretation of NT measurements in multiparous women.
Distribution of NT MoM NT MoM <95%ile NT MoM >95%ile 1st Pregnancy
7559 (95.5%)
353(4.5%)
2nd Pregnancy 7561 (95.6%)
351 (4.4%)
563 Estimated placental volume (EPV): a novel predictor of small for gestational age birth weight (SGA) Katherine H. Campbell1, France Galerneau1, Harvey Kliman1, Radek K. Bukowski1 1
Yale University, New Haven, CT
OBJECTIVE: Traditionally SGA is predicted and further pregnancy
management defined on the ultrasound generated estimated fetal weight (EFW). The aim of this study was to evaluate predictive ability of simple 2D ultrasound EPV to predict SGA birth weight. STUDY DESIGN: In a prospective cohort study of 371 pregnant women the EPV and EFW of ongoing singleton gestations was calculated. From this, we identified 77 women with EPV and EFW measurements obtained between 15 weeks 4 days and 23 weeks 6 days with birth weights available for assessment. EPV was measured using a validated mathematical model (Azpurua et al, 2010) that uses the maximal width, height, and thickness of the placenta obtained at the time of obstetrical ultrasound. Both EPV and EFW percentiles for gestational age were calculated and used for analysis. SGA was defined as birth weight < 10th percentile for gestational age. The abilities of EPV or EFW to predict SGA were evaluated using logistic regression, area under Receiver Operating Characteristics Curve (aROC), Integrated Discrimination Improvement (IDI) and Net Reclassification Improvement (NRI). RESULTS: EPV unlike EFW was associated with significant reduction in the risk of SGA at the rate of 4% reduction for each percentile increase in EPV (OR [95% CI], 0.96 [0.93-0.99], p¼0.004). EPV was also associated with a trend in increase in aROC comparing to EFW (78% vs 62%, p¼0.059). There was no evidence of significant miscalibration of either EPV or EFW models predicting SGA. EPV was associated with a significant and strong improvement in reclassification when considered in addition to EFW (IDI¼0.13, p¼0.0004 and NRI¼1.15, p¼0.0001. The 115% improvement in NRI was composed of 84% improvement of true positives and 31% improvement in true negatives.
CONCLUSION: EPV provides a new effective predictor of SGA which significantly improves predictive ability of traditionally used EFW. Future studies should concentrate on external validation and identification of optimal cut-offs for the clinical use.
564 A sonographic protocol of standardized physics settings to improve detection of placenta accreta Barbora Mrazek-Pugh1, Amanda Yeaton-Massey2, Jane Chueh2, Deirdre Lyell2 1
Lucile Packard Children’s Hospital at Stanford, Palo Alto, CA, 2Department of Obstetrics & Gynecology, Stanford University School of Medicine, Stanford, CA
OBJECTIVE: The reported accuracy of ultrasound in the detection of
placenta accreta is variable yet such accuracy is critical for delivery planning. Assessment of several sonographic markers of accreta have been described to improve accuracy, but the importance of ultrasound machine settings in accurately assessing these markers is often not considered. We sought to investigate whether the use of a sonographic protocol with standardized ultrasound physics settings could improve the detection of placenta accreta. STUDY DESIGN: Women with suspected placenta accreta were assessed by routine ultrasound by MFM specialists and Pediatric Radiologists from 2011-2013. In 2014, all sonographers and attending physicians were trained in the new standardized physics settings (Table). The lead sonographer (BMP) performed a quality review to ensure universal protocol adherence. Scans that deviated from the protocol were reviewed with the performing team and the patient was rescanned. The primary outcome was accurate sonographic prediction of placenta accreta as determined by clinical and pathologic measures. Positive predictive value (PPV) and negative predictive value (NPV) were calculated. RESULTS: 63 women were evaluated; 38 using the prior standard sonographic assessment and 25 using the new protocol. The PPV and NPV for accurate sonographic assessment of accreta were 75% and 71% prior to implementation of the new protocol, and 100% and 100% respectively after implementation. CONCLUSION: The use of standardized physics settings in the evaluation of suspected placenta accreta significantly improved the PPV and NPV of sonographic detection of accreta. By standardizing the settings of 2D, color Doppler and pulse wave Doppler, and by performing a quality review to ensure these settings were used, one can increase the accuracy of sonographic detection of placenta accreta, allowing for appropriate delivery planning.
Supplement to JANUARY 2016 American Journal of Obstetrics & Gynecology
S303