858: Polyhydramnios and adverse perinatal outcome - Comparing two ultrasound methods of diagnosing polyhydramnios and their association with adverse perinatal outcome.

Abstract

ObjectiveThe aim of this study was to determine which measure of polyhydramnios- AFI (Amniotic Fluid Index) or DVP (Deepest Vertical Pocket) - is more strongly correlated with adverse perinatal outcomes.Study DesignThis retrospective cohort study was drawn from singleton pregnancies receiving a prenatal ultrasound scan >28+0 weeks’ gestation at the BC Women’s Hospital (Vancouver, Canada), 2000-2014. Polyhydramnios was defined as an AFI >=24 cm or DVP>=8 cm. Ultrasound data were linked with the hospital’s quality-controlled obstetric and neonatal database, which contains abstracted medical chart data. Adverse perinatal outcome was defined as any of: stillbirth, in-hospital newborn death, or level 2 or 3 neonatal intensive care unit admission. Correlation was measured with Pearson’s r, and differences in risk between groups examined using logistic regression.ResultsAmong 1029 pregnancies with polyhydramnios, the diagnosis was based on DVP alone for 607 patients (59%), AFI alone for 75 patients (7%) and both methods for 347 patients (34%). AFI and DVP were moderately correlated (r=0.56). There were 32 perinatal deaths (3.1%). Compared with pregnancies diagnosed by DVP alone, pregnancies diagnosed by AFI alone had a higher risk of adverse perinatal outcome (15% vs 29%, respectively [Figure 1]; odds ratio (OR) 2.3, 95% CI: 1.3 to 3.9). The highest risk was observed in pregnancies diagnosed with both methods (33%; OR 2.49, 95% CI 2.0 to 3.7). Every 1cm increase in AFI was associated with an 11% increase in odds of adverse outcome [95% CI: 1.08 to 1.15], while DVP did not provide additional information on adverse outcome above and beyond that obtained from AFI (OR 1.04 per 1 cm increase in DVP, 95% CI: 0.91 to 1.19).Conclusion ObjectiveThe aim of this study was to determine which measure of polyhydramnios- AFI (Amniotic Fluid Index) or DVP (Deepest Vertical Pocket) - is more strongly correlated with adverse perinatal outcomes. The aim of this study was to determine which measure of polyhydramnios- AFI (Amniotic Fluid Index) or DVP (Deepest Vertical Pocket) - is more strongly correlated with adverse perinatal outcomes. Study DesignThis retrospective cohort study was drawn from singleton pregnancies receiving a prenatal ultrasound scan >28+0 weeks’ gestation at the BC Women’s Hospital (Vancouver, Canada), 2000-2014. Polyhydramnios was defined as an AFI >=24 cm or DVP>=8 cm. Ultrasound data were linked with the hospital’s quality-controlled obstetric and neonatal database, which contains abstracted medical chart data. Adverse perinatal outcome was defined as any of: stillbirth, in-hospital newborn death, or level 2 or 3 neonatal intensive care unit admission. Correlation was measured with Pearson’s r, and differences in risk between groups examined using logistic regression. This retrospective cohort study was drawn from singleton pregnancies receiving a prenatal ultrasound scan >28+0 weeks’ gestation at the BC Women’s Hospital (Vancouver, Canada), 2000-2014. Polyhydramnios was defined as an AFI >=24 cm or DVP>=8 cm. Ultrasound data were linked with the hospital’s quality-controlled obstetric and neonatal database, which contains abstracted medical chart data. Adverse perinatal outcome was defined as any of: stillbirth, in-hospital newborn death, or level 2 or 3 neonatal intensive care unit admission. Correlation was measured with Pearson’s r, and differences in risk between groups examined using logistic regression. ResultsAmong 1029 pregnancies with polyhydramnios, the diagnosis was based on DVP alone for 607 patients (59%), AFI alone for 75 patients (7%) and both methods for 347 patients (34%). AFI and DVP were moderately correlated (r=0.56). There were 32 perinatal deaths (3.1%). Compared with pregnancies diagnosed by DVP alone, pregnancies diagnosed by AFI alone had a higher risk of adverse perinatal outcome (15% vs 29%, respectively [Figure 1]; odds ratio (OR) 2.3, 95% CI: 1.3 to 3.9). The highest risk was observed in pregnancies diagnosed with both methods (33%; OR 2.49, 95% CI 2.0 to 3.7). Every 1cm increase in AFI was associated with an 11% increase in odds of adverse outcome [95% CI: 1.08 to 1.15], while DVP did not provide additional information on adverse outcome above and beyond that obtained from AFI (OR 1.04 per 1 cm increase in DVP, 95% CI: 0.91 to 1.19). Among 1029 pregnancies with polyhydramnios, the diagnosis was based on DVP alone for 607 patients (59%), AFI alone for 75 patients (7%) and both methods for 347 patients (34%). AFI and DVP were moderately correlated (r=0.56). There were 32 perinatal deaths (3.1%). Compared with pregnancies diagnosed by DVP alone, pregnancies diagnosed by AFI alone had a higher risk of adverse perinatal outcome (15% vs 29%, respectively [Figure 1]; odds ratio (OR) 2.3, 95% CI: 1.3 to 3.9). The highest risk was observed in pregnancies diagnosed with both methods (33%; OR 2.49, 95% CI 2.0 to 3.7). Every 1cm increase in AFI was associated with an 11% increase in odds of adverse outcome [95% CI: 1.08 to 1.15], while DVP did not provide additional information on adverse outcome above and beyond that obtained from AFI (OR 1.04 per 1 cm increase in DVP, 95% CI: 0.91 to 1.19). Conclusion