- Email: [email protected]
611: Electronic fetal heart rate patterns in the second stage of labor: utility of the NICHD nomenclature
Poster Session IV
Epidemiology, Infectious Disease, Intrapartum Fetal Assessment, Operative Obstetrics, Obstetric Quality & Safety, Public Health-Global Health
2002-2008. Body mass index (BMI) data existed for 116, 474 term singleton pregnancies after exclusion of long term steroid use and anomalies. Infectious outcomes were analyzed, including endometritis, chorioamnionitis, group B streptococcus (GBS), antenatal urinary tract infections (UTI), and wound infections. Infectious neonatal data were analyzed, including neonatal fever, sepsis, and pneumonia. Relative risk (RR) analyses were performed comparing normal weight (BMI 18.50-24.49) and underweight (BMI 50.00) patients with their corresponding neonatal data. Regression analyses were performed to account for confounding factors. RESULTS: Obese patients were at increased risk for wound infections (RR ⫽1.96, 95% CI 1.55-2.47, P⬍0.0001), as well as endometritis (RR⫽ 1.62, 95% CI 1.19-2.22, P ⫽ 0.0021), UTIs (RR⫽ 1.33, 95% CI 1.23-1.43, P⬍0.0001), and GBS (RR⫽1.22, 95% CI 1.18-1.26, P⬍0.0001). Interestingly, obesity was protective against chorioamnionitis with a RR of 0.83 (95% CI .074-0.92, P ⫽ 0.0003). The multivariable logistic regression analysis showed that only race, age parity, and number of vaginal exams were risk factors for chorioamnionitis. Age, parity, and diabetes were risk factors for endometritis. Maternal obesity had no correlation with infectious neonatal outcomes. CONCLUSION: In addition to the predisposition to wound infections, obesity is a risk factor for endometritis, GBS, and antenatal UTIs. After regression analysis endometritis and chorioamnionitis do not have any significant association with obesity. Maternal obesity is not a risk factor for neonatal infections.
609 The impact of prompt diagnosis and treatment on maternal and perinatal outcome in pregnant women with influenza A (H1N1) Paola Bordoni1, Yvette C. Cordova2, JoNell Potter1, Salih Yasin1, Amanda Cotter3 1 University of Miami, Department of Obstetrics and Gynecology, Miami, FL, 2University of Miami, Department of Obstetrics and Gynecology, Miami, FL, 3University of Miami Miller School of Medicine, Obstetrics & Gynecology, Miami, FL
OBJECTIVE: To investigate the impact of implementation of the 2009 H1N1 CDC guidelines regarding the diagnosis and treatment of H1N1 in a high risk obstetric population prior to the introduction of vaccination and subsequent maternal and perinatal outcome. STUDY DESIGN: A retrospective study was conducted of all pregnant women diagnosed with Influenza - like Illness (ILI) during the interval 5/1/09 - 5/26/10 at a tertiary care referral center where there were 5,346 deliveries during this period. Eligibility criteria included cases that were confirmed or probable 2009 H1N1 virus infection. Cases were confirmed positive for H1N1 by culture or PCR, presumptive positive if influenza A positive with negative PCR and clinically positive if no PCR or culture positive but with a clinical diagnosis made as a result of a multidisciplinary review by MFM, ID and Internal Medicine specialists. Maternal risk factors were identified and maternal and perinatal outcomes reviewed. RESULTS: A total of 48 pregnant patients met inclusion criteria; 43 were H1N1 confirmed positive, 1 presumptive positive and 4 diagnosed clinically. There were three maternal deaths pre-guideline implementation and no deaths post-guideline introduction (p⬍0.005). Four mothers were admitted to ICU pre and two post guidelines (p⬍0.01). Four mothers required intubation pre and only one post guidelines (p⬍0.005). Co-morbidities (including pre-existing respiratory disease and immunodeficiency) did not appear to further increase the risk of adverse outcome. Perinatal outcomes were not significantly affected by H1N1 diagnosis and there were no neonatal deaths. CONCLUSION: Prompt diagnosis and treatment of H1N1 in pregnancy as a result of the introduction of CDC guidelines resulted in a significant decrease in maternal morbidities and appears to have protected against maternal death. Regardless of co-morbidities, pregnancy appeared to be the single most significant risk factor for affecting outcomes in H1N1 infection.
S274
www.AJOG.org
610 Pre-pregnancy gastric bypass for the morbidly obese: a decision and economic analysis Alison G. Cahill1, Anthony Odibo1, Emily Jungheim1, Rachel Pilliod2, William Grobman3, George Macones1, Aaron Caughey2 1 Washington University in St. Louis, Department of Obstetrics and Gynecology, St. Louis, MO, 2Oregon Health & Science University, Department of Obstetrics and Gynecology, Portland, OR, 3Northwestern University Feinberg School of Medicine, Obstetrics and Gynecology, Chicago, IL
OBJECTIVE: There is an increased risk of adverse pregnancy outcomes associated with morbid obesity, but a lack of evidence for the efficacy of non-surgical strategies for weight loss. We constructed an model to determine whether pre-pregnancy gastric bypass, with corresponding weight reduction and improved perinatal outcomes, is a cost-effective strategy. STUDY DESIGN: A decision analytic model was designed to compare 2 pre-pregnancy strategies for morbidly obese women (BMIⱖ 40): laparoscopic gastric banding (LGB) 1 year prior to pregnancy or no pre-pregnancy surgery. The model was constructed from the societal perspective, and designed for the first pregnancy after surgery. We assumed a 20% weight-loss after LGB, based on published data. Modeled outcomes included: stillbirth, gestational diabetes, preeclampsia, preterm birth, and neonatal death. Probabilities, utilities, and costs from the published literature were used. Strategies were compared by cost per quality-adjusted life-years (QALYs) and cost per number of adverse clinical events prevented. RESULTS: For every 10,000 morbidly obese women, LGB would prevent 23 stillbirths, 250 cases of gestational diabetes, 20 preterm births, 380 cesareans, and 3 neonatal deaths. These improved outcomes resulted in LGB being a more effective strategy. However, because of the costs incurred, LGB was not cost-effective in the base-case analysis with an incremental cost of ⬎$220,000 per QALY gained. The preferred strategy was not changed in sensitivity analyses when the estimates were varied across their ranges. LGB, or any weight-loss strategy, would need to cost less than $700 for it to become cost-effective. CONCLUSION: LGB one year prior to pregnancy in morbidly obese women is not cost effective, though it would reduce the average number of adverse pregnancy events. This is most likely due to the fact that the average weight-loss after LGB in women with Class III obesity will, on average, still result in a pregnancy complicated by Class II obesity, which minimizes the impact that might be expected.
611 Electronic fetal heart rate patterns in the second stage of labor: utility of the NICHD nomenclature Alison G. Cahill1, Anthony Odibo1, Kimberly Roehl1, George Macones1 1 Washington University in St. Louis, Department of Obstetrics and Gynecology, St. Louis, MO
OBJECTIVE: No published data exists describing the normal frequency and distribution of EFM Categories and features in the second stage of labor, which the NICHD highlighted as a critical knowledge gap. We
American Journal of Obstetrics & Gynecology Supplement to JANUARY 2012
www.AJOG.org
Epidemiology, Infectious Disease, Intrapartum Fetal Assessment, Operative Obstetrics, Obstetric Quality & Safety, Public Health-Global Health
undertook this study to estimate the incidence of Categories and features, including deceleration types, immediately prior to delivery. STUDY DESIGN: A 5-year retrospective cohort study of all consecutive terms births (ⱖ37 weeks) who labored, delivered from the second stage, and had at least 10 minutes of EFM prior to delivery. Two formally trained research nurses, interpreted the 30 minutes of EFM prior to delivery, blind to clinical features and pregnancy outcomes. The 30 minutes of EFM immediately prior to delivery was interpreted in 10-minute epochs, as well as over-all, using the 2008 NICHD criteria with a closed-ended tool. Descriptive were used to estimate incidence of Categories and features within the cohort. RESULTS: 5,388 consecutive term deliveries met inclusion for this study; 57 (1.1%) with pH ⱕ 7.10 at birth. In the 30 minutes prior to birth, 97.6% (n⫽5,261) of the patterns were Category II and 2.3% (n⫽122) were Category I. Only 5 (0.09%) women had a Category III tracing in the 30 minutes prior to delivery, and zero Category III tracings occurred in women who delivered infants with acidemia. Conversely, of the infants with acidemia at birth, 32 (71.1%) had moderate variability and 2 (3.9%) had a Category I tracing. CONCLUSION: Category III EFM patterns occur with such rarity in the second stage of labor that the value of the 3-tiered NICHD nomenclature system to discriminate between cases of acidosis and nonacidosis is vastly diminished. We found Category I tracings and moderate variability in infants with acidemia, raising concern for the reassurance that the presence of these features assures normal pH in the second stage of labor.
Poster Session IV
defined as umbilical cord pH ⱕ 7.10. Incidence of atypical features and risks of acidemia with 95% confidence intervals were calculated. RESULTS: Within 5,388 women, the atypical feature seen with the most frequency was shoulders (n⫽2914, 54.1%), followed by slow return (n⫽2618, 48.6%), minimal deceleration variability (n⫽430, 8.0%). An overshoot was seen one time. There was no difference in the incidence of atypical features between the 57 infants with acidemia and the 5331 infants without. Similarly, there was no difference in mean atypical score, and no difference in rates of atypical overall scores above 5 (29.8% vs. 22.8%, p⫽0.21) between infants with and without acidemia, respectively. CONCLUSION: Our findings support the consensus recommendations to remove deceleration qualifiers from EFM interpretation, as they are not correlated with acidemia in the second stage of labor.
613 Intrapartum electronic fetal monitoring and the identification of neonates with hypoxic-ischemic encephalopathy treated with hypothermia protocol Cynthia L. Anderson1, Christoph U. Lehmann2, Frank R. Witter1, Ernest Graham3 1 Johns Hopkins University School of Medicine, Department of Gynecology & Obstetrics, Division of Maternal-Fetal Medicine, Baltimore, MD, 2Johns Hopkins School of Medicine, Department of Pediatrics, Division of Neonatology, Baltimore, MD, 3Johns Hopkins University School of Medicine, Gynecology and Obstetrics, Division of Maternal-Fetal Medicine, Baltimore, MD
612 Slow returns and overshoots: do they mean anything? Alison G. Cahill1, Anthony Odibo1, Kimberly Roehl1, George Macones1 1 Washington University in St. Louis, Department of Obstetrics and Gynecology, St. Louis, MO
OBJECTIVE: The 2008 NICHD definitions for electronic fetal monitoring (EFM) interpretation in labor specifically called for discontinuation of use of qualifying terms which further characterized decelerations but had no known association with outcome. We aimed to rigorously test the association between these atypical deceleration features and acidemia. STUDY DESIGN: During a 5-year retrospective cohort study of all singleton, non-anomalous gestations delivered at ⱖ 37 weeks from the second stage of labor, in which the 30 minutes of EFM immediately prior to delivery were interpreted by 2 dedicated and formally trained research nurses, blind to clinical and outcome data, deceleration features which were historically referred to a atypical were also extracted. Specifically, overshoots, shoulders, slow-return, and minimal or absent variability within the deceleration were extracted with strict definitions. Finally, each deceleration was given an atypical score with a single point for each atypical feature; the scores were summed for each tracing to give an atypical overall score for each patient. Acidemia was
OBJECTIVE: Electronic fetal monitoring is the tool used to rapidly identify hypoxic-ischemic encephalopathy (HIE). We sought to determine how well the last hour of intrapartum monitoring prior to delivery can identify neonates meeting criteria for treatment with whole body cooling within 6 hours of birth. STUDY DESIGN: This is a case-control study of all 26 neonates born at 2 university hospitals between 1/1/07-7/1/11 treated with whole body cooling. Neonates treated with hypothermia were matched to the subsequent delivery by gestational age and mode of delivery. The last hour of fetal heart rate monitoring prior to delivery was read by 3 maternalfetal medicine specialists using the 2008 NICHD guidelines and the readings averaged. Tracing parameters were compared using paired t tests and McNemara chi square. Assuming 3 ⫹/⫺ 3 late decelerations/ hour for controls and alpha⫽0.05, a sample size of 16 patients in each group would have an 80% power to detect an increase to 6 late decelerations/hour in cases. RESULTS: Cases treated with hypothermia did not differ from controls in gestational age (39 ⫹/⫺ 1.7 vs. 39 ⫹/⫺ 1.6 weeks) or birth weight (3254 ⫹/⫺ 590 vs. 3082 ⫹/⫺409 grams). The cesarean rate for both groups was 61.5%, and nonreassuring fetal heart rate tracing was noted as an indication for delivery in 87.5% of cases and 68.8% of controls. Neonates undergoing cooling had a significantly more acidotic cord pH (7.00 ⫹/⫺ 0.11 vs. 7.25 ⫹/⫺ 0.05, p⬍0.0001) and base deficit (13.7 ⫹/⫺ 4.8 vs. 3.4 ⫹/⫺ 2.4 mM, p⬍0.0001). Sentinel events
Supplement to JANUARY 2012 American Journal of Obstetrics & Gynecology
S275
Epidemiology, Infectious Disease, Intrapartum Fetal Assessment, Operative Obstetrics, Obstetric Quality & Safety, Public Health-Global Health
2002-2008. Body mass index (BMI) data existed for 116, 474 term singleton pregnancies after exclusion of long term steroid use and anomalies. Infectious outcomes were analyzed, including endometritis, chorioamnionitis, group B streptococcus (GBS), antenatal urinary tract infections (UTI), and wound infections. Infectious neonatal data were analyzed, including neonatal fever, sepsis, and pneumonia. Relative risk (RR) analyses were performed comparing normal weight (BMI 18.50-24.49) and underweight (BMI 50.00) patients with their corresponding neonatal data. Regression analyses were performed to account for confounding factors. RESULTS: Obese patients were at increased risk for wound infections (RR ⫽1.96, 95% CI 1.55-2.47, P⬍0.0001), as well as endometritis (RR⫽ 1.62, 95% CI 1.19-2.22, P ⫽ 0.0021), UTIs (RR⫽ 1.33, 95% CI 1.23-1.43, P⬍0.0001), and GBS (RR⫽1.22, 95% CI 1.18-1.26, P⬍0.0001). Interestingly, obesity was protective against chorioamnionitis with a RR of 0.83 (95% CI .074-0.92, P ⫽ 0.0003). The multivariable logistic regression analysis showed that only race, age parity, and number of vaginal exams were risk factors for chorioamnionitis. Age, parity, and diabetes were risk factors for endometritis. Maternal obesity had no correlation with infectious neonatal outcomes. CONCLUSION: In addition to the predisposition to wound infections, obesity is a risk factor for endometritis, GBS, and antenatal UTIs. After regression analysis endometritis and chorioamnionitis do not have any significant association with obesity. Maternal obesity is not a risk factor for neonatal infections.
609 The impact of prompt diagnosis and treatment on maternal and perinatal outcome in pregnant women with influenza A (H1N1) Paola Bordoni1, Yvette C. Cordova2, JoNell Potter1, Salih Yasin1, Amanda Cotter3 1 University of Miami, Department of Obstetrics and Gynecology, Miami, FL, 2University of Miami, Department of Obstetrics and Gynecology, Miami, FL, 3University of Miami Miller School of Medicine, Obstetrics & Gynecology, Miami, FL
OBJECTIVE: To investigate the impact of implementation of the 2009 H1N1 CDC guidelines regarding the diagnosis and treatment of H1N1 in a high risk obstetric population prior to the introduction of vaccination and subsequent maternal and perinatal outcome. STUDY DESIGN: A retrospective study was conducted of all pregnant women diagnosed with Influenza - like Illness (ILI) during the interval 5/1/09 - 5/26/10 at a tertiary care referral center where there were 5,346 deliveries during this period. Eligibility criteria included cases that were confirmed or probable 2009 H1N1 virus infection. Cases were confirmed positive for H1N1 by culture or PCR, presumptive positive if influenza A positive with negative PCR and clinically positive if no PCR or culture positive but with a clinical diagnosis made as a result of a multidisciplinary review by MFM, ID and Internal Medicine specialists. Maternal risk factors were identified and maternal and perinatal outcomes reviewed. RESULTS: A total of 48 pregnant patients met inclusion criteria; 43 were H1N1 confirmed positive, 1 presumptive positive and 4 diagnosed clinically. There were three maternal deaths pre-guideline implementation and no deaths post-guideline introduction (p⬍0.005). Four mothers were admitted to ICU pre and two post guidelines (p⬍0.01). Four mothers required intubation pre and only one post guidelines (p⬍0.005). Co-morbidities (including pre-existing respiratory disease and immunodeficiency) did not appear to further increase the risk of adverse outcome. Perinatal outcomes were not significantly affected by H1N1 diagnosis and there were no neonatal deaths. CONCLUSION: Prompt diagnosis and treatment of H1N1 in pregnancy as a result of the introduction of CDC guidelines resulted in a significant decrease in maternal morbidities and appears to have protected against maternal death. Regardless of co-morbidities, pregnancy appeared to be the single most significant risk factor for affecting outcomes in H1N1 infection.
S274
www.AJOG.org
610 Pre-pregnancy gastric bypass for the morbidly obese: a decision and economic analysis Alison G. Cahill1, Anthony Odibo1, Emily Jungheim1, Rachel Pilliod2, William Grobman3, George Macones1, Aaron Caughey2 1 Washington University in St. Louis, Department of Obstetrics and Gynecology, St. Louis, MO, 2Oregon Health & Science University, Department of Obstetrics and Gynecology, Portland, OR, 3Northwestern University Feinberg School of Medicine, Obstetrics and Gynecology, Chicago, IL
OBJECTIVE: There is an increased risk of adverse pregnancy outcomes associated with morbid obesity, but a lack of evidence for the efficacy of non-surgical strategies for weight loss. We constructed an model to determine whether pre-pregnancy gastric bypass, with corresponding weight reduction and improved perinatal outcomes, is a cost-effective strategy. STUDY DESIGN: A decision analytic model was designed to compare 2 pre-pregnancy strategies for morbidly obese women (BMIⱖ 40): laparoscopic gastric banding (LGB) 1 year prior to pregnancy or no pre-pregnancy surgery. The model was constructed from the societal perspective, and designed for the first pregnancy after surgery. We assumed a 20% weight-loss after LGB, based on published data. Modeled outcomes included: stillbirth, gestational diabetes, preeclampsia, preterm birth, and neonatal death. Probabilities, utilities, and costs from the published literature were used. Strategies were compared by cost per quality-adjusted life-years (QALYs) and cost per number of adverse clinical events prevented. RESULTS: For every 10,000 morbidly obese women, LGB would prevent 23 stillbirths, 250 cases of gestational diabetes, 20 preterm births, 380 cesareans, and 3 neonatal deaths. These improved outcomes resulted in LGB being a more effective strategy. However, because of the costs incurred, LGB was not cost-effective in the base-case analysis with an incremental cost of ⬎$220,000 per QALY gained. The preferred strategy was not changed in sensitivity analyses when the estimates were varied across their ranges. LGB, or any weight-loss strategy, would need to cost less than $700 for it to become cost-effective. CONCLUSION: LGB one year prior to pregnancy in morbidly obese women is not cost effective, though it would reduce the average number of adverse pregnancy events. This is most likely due to the fact that the average weight-loss after LGB in women with Class III obesity will, on average, still result in a pregnancy complicated by Class II obesity, which minimizes the impact that might be expected.
611 Electronic fetal heart rate patterns in the second stage of labor: utility of the NICHD nomenclature Alison G. Cahill1, Anthony Odibo1, Kimberly Roehl1, George Macones1 1 Washington University in St. Louis, Department of Obstetrics and Gynecology, St. Louis, MO
OBJECTIVE: No published data exists describing the normal frequency and distribution of EFM Categories and features in the second stage of labor, which the NICHD highlighted as a critical knowledge gap. We
American Journal of Obstetrics & Gynecology Supplement to JANUARY 2012
www.AJOG.org
Epidemiology, Infectious Disease, Intrapartum Fetal Assessment, Operative Obstetrics, Obstetric Quality & Safety, Public Health-Global Health
undertook this study to estimate the incidence of Categories and features, including deceleration types, immediately prior to delivery. STUDY DESIGN: A 5-year retrospective cohort study of all consecutive terms births (ⱖ37 weeks) who labored, delivered from the second stage, and had at least 10 minutes of EFM prior to delivery. Two formally trained research nurses, interpreted the 30 minutes of EFM prior to delivery, blind to clinical features and pregnancy outcomes. The 30 minutes of EFM immediately prior to delivery was interpreted in 10-minute epochs, as well as over-all, using the 2008 NICHD criteria with a closed-ended tool. Descriptive were used to estimate incidence of Categories and features within the cohort. RESULTS: 5,388 consecutive term deliveries met inclusion for this study; 57 (1.1%) with pH ⱕ 7.10 at birth. In the 30 minutes prior to birth, 97.6% (n⫽5,261) of the patterns were Category II and 2.3% (n⫽122) were Category I. Only 5 (0.09%) women had a Category III tracing in the 30 minutes prior to delivery, and zero Category III tracings occurred in women who delivered infants with acidemia. Conversely, of the infants with acidemia at birth, 32 (71.1%) had moderate variability and 2 (3.9%) had a Category I tracing. CONCLUSION: Category III EFM patterns occur with such rarity in the second stage of labor that the value of the 3-tiered NICHD nomenclature system to discriminate between cases of acidosis and nonacidosis is vastly diminished. We found Category I tracings and moderate variability in infants with acidemia, raising concern for the reassurance that the presence of these features assures normal pH in the second stage of labor.
Poster Session IV
defined as umbilical cord pH ⱕ 7.10. Incidence of atypical features and risks of acidemia with 95% confidence intervals were calculated. RESULTS: Within 5,388 women, the atypical feature seen with the most frequency was shoulders (n⫽2914, 54.1%), followed by slow return (n⫽2618, 48.6%), minimal deceleration variability (n⫽430, 8.0%). An overshoot was seen one time. There was no difference in the incidence of atypical features between the 57 infants with acidemia and the 5331 infants without. Similarly, there was no difference in mean atypical score, and no difference in rates of atypical overall scores above 5 (29.8% vs. 22.8%, p⫽0.21) between infants with and without acidemia, respectively. CONCLUSION: Our findings support the consensus recommendations to remove deceleration qualifiers from EFM interpretation, as they are not correlated with acidemia in the second stage of labor.
613 Intrapartum electronic fetal monitoring and the identification of neonates with hypoxic-ischemic encephalopathy treated with hypothermia protocol Cynthia L. Anderson1, Christoph U. Lehmann2, Frank R. Witter1, Ernest Graham3 1 Johns Hopkins University School of Medicine, Department of Gynecology & Obstetrics, Division of Maternal-Fetal Medicine, Baltimore, MD, 2Johns Hopkins School of Medicine, Department of Pediatrics, Division of Neonatology, Baltimore, MD, 3Johns Hopkins University School of Medicine, Gynecology and Obstetrics, Division of Maternal-Fetal Medicine, Baltimore, MD
612 Slow returns and overshoots: do they mean anything? Alison G. Cahill1, Anthony Odibo1, Kimberly Roehl1, George Macones1 1 Washington University in St. Louis, Department of Obstetrics and Gynecology, St. Louis, MO
OBJECTIVE: The 2008 NICHD definitions for electronic fetal monitoring (EFM) interpretation in labor specifically called for discontinuation of use of qualifying terms which further characterized decelerations but had no known association with outcome. We aimed to rigorously test the association between these atypical deceleration features and acidemia. STUDY DESIGN: During a 5-year retrospective cohort study of all singleton, non-anomalous gestations delivered at ⱖ 37 weeks from the second stage of labor, in which the 30 minutes of EFM immediately prior to delivery were interpreted by 2 dedicated and formally trained research nurses, blind to clinical and outcome data, deceleration features which were historically referred to a atypical were also extracted. Specifically, overshoots, shoulders, slow-return, and minimal or absent variability within the deceleration were extracted with strict definitions. Finally, each deceleration was given an atypical score with a single point for each atypical feature; the scores were summed for each tracing to give an atypical overall score for each patient. Acidemia was
OBJECTIVE: Electronic fetal monitoring is the tool used to rapidly identify hypoxic-ischemic encephalopathy (HIE). We sought to determine how well the last hour of intrapartum monitoring prior to delivery can identify neonates meeting criteria for treatment with whole body cooling within 6 hours of birth. STUDY DESIGN: This is a case-control study of all 26 neonates born at 2 university hospitals between 1/1/07-7/1/11 treated with whole body cooling. Neonates treated with hypothermia were matched to the subsequent delivery by gestational age and mode of delivery. The last hour of fetal heart rate monitoring prior to delivery was read by 3 maternalfetal medicine specialists using the 2008 NICHD guidelines and the readings averaged. Tracing parameters were compared using paired t tests and McNemara chi square. Assuming 3 ⫹/⫺ 3 late decelerations/ hour for controls and alpha⫽0.05, a sample size of 16 patients in each group would have an 80% power to detect an increase to 6 late decelerations/hour in cases. RESULTS: Cases treated with hypothermia did not differ from controls in gestational age (39 ⫹/⫺ 1.7 vs. 39 ⫹/⫺ 1.6 weeks) or birth weight (3254 ⫹/⫺ 590 vs. 3082 ⫹/⫺409 grams). The cesarean rate for both groups was 61.5%, and nonreassuring fetal heart rate tracing was noted as an indication for delivery in 87.5% of cases and 68.8% of controls. Neonates undergoing cooling had a significantly more acidotic cord pH (7.00 ⫹/⫺ 0.11 vs. 7.25 ⫹/⫺ 0.05, p⬍0.0001) and base deficit (13.7 ⫹/⫺ 4.8 vs. 3.4 ⫹/⫺ 2.4 mM, p⬍0.0001). Sentinel events
Supplement to JANUARY 2012 American Journal of Obstetrics & Gynecology
S275