Variation in Hospital Neuraxial Labor Analgesia Rates in California.

BACKGROUND: Neuraxial analgesia provides effective pain relief during labor. However, it is unclear whether neuraxial analgesia prevalence differs across U.S. hospitals. The aim of this study was to assess hospital variation in neuraxial analgesia prevalence in California. METHODS: A retrospective cross-sectional study analyzed birthing patients who underwent labor in 200 California hospitals from 2016 to 2020. The primary exposure was the delivery hospital. The outcomes were hospital neuraxial analgesia prevalence and between-hospital variability, before and after adjustment for patient and hospital factors. Median odds ratio and intraclass correlation coefficients quantified between-hospital variability. The median odds ratio estimated the odds of a patient receiving neuraxial analgesia when moving between hospitals. The intraclass correlation coefficients quantified the proportion of the total variance in neuraxial analgesia use due to variation between hospitals. RESULTS: Among 1,510,750 patients who underwent labor, 1,040,483 (68.9%) received neuraxial analgesia. Both unadjusted and adjusted hospital prevalence exhibited a skewed distribution characterized by a long left tail. The unadjusted and adjusted prevalences were 5.4% and 6.0% at the 1st percentile, 21.0% and 21.2% at the 5th percentile, 70.6% and 70.7% at the 50th percentile, 75.8% and 76.6% at the 95th percentile, and 75.9% and 78.6% at the 99th percentile, respectively. The adjusted median odds ratio (2.3; 95% CI, 2.1 to 2.5) indicated substantially increased odds of a patient receiving neuraxial analgesia if they moved from a hospital with a lower odds of neuraxial analgesia to one with higher odds. The hospital explained only a moderate portion of the overall variability in neuraxial analgesia (intraclass correlation coefficient, 19.1%; 95% CI, 18.8 to 20.5%). CONCLUSIONS: A long left tail in the distribution and wide variation exist in the neuraxial analgesia prevalence across California hospitals that is not explained by patient and hospital factors. Addressing the low prevalence among hospitals in the left tail requires exploration of the interplay between patient preferences, staffing availability, and care providers' attitudes toward neuraxial analgesia.

Validity of ICD-10 diagnosis codes for placenta accreta spectrum disorders.

BACKGROUND: The 10th revision of the International Classification of Diseases, Clinical Modification (ICD-10) includes diagnosis codes for placenta accreta spectrum for the first time. These codes could enable valuable research and surveillance of placenta accreta spectrum, a life-threatening pregnancy complication that is increasing in incidence. OBJECTIVE: We sought to evaluate the validity of placenta accreta spectrum diagnosis codes that were introduced in ICD-10 and assess contributing factors to incorrect code assignments. METHODS: We calculated sensitivity, specificity, positive predictive value and negative predictive value of the ICD-10 placenta accreta spectrum code assignments after reviewing medical records from October 2015 to March 2020 at a quaternary obstetric centre. Histopathologic diagnosis was considered the gold standard. RESULTS: Among 22,345 patients, 104 (0.46%) had an ICD-10 code for placenta accreta spectrum and 51 (0.23%) had a histopathologic diagnosis. ICD-10 codes had a sensitivity of 0.71 (95% CI 0.56, 0.83), specificity of 0.98 (95% CI 0.93, 1.00), positive predictive value of 0.61 (95% CI 0.48, 0.72) and negative predictive value of 1.00 (95% CI 0.96, 1.00). The sensitivities of the ICD-10 codes for placenta accreta spectrum subtypes- accreta, increta and percreta-were 0.55 (95% CI 0.31, 0.78), 0.33 (95% CI 0.12, 0.62) and 0.56 (95% CI 0.31, 0.78), respectively. Cases with incorrect code assignment were less morbid than cases with correct code assignment, with a lower incidence of hysterectomy at delivery (17% vs 100%), blood transfusion (26% vs 75%) and admission to the intensive care unit (0% vs 53%). Primary reasons for code misassignment included code assigned to cases of occult placenta accreta (35%) or to cases with clinical evidence of placental adherence without histopatholic diagnostic (35%) features. CONCLUSION: These findings from a quaternary obstetric centre suggest that ICD-10 codes may be useful for research and surveillance of placenta accreta spectrum, but researchers should be aware of likely substantial false positive cases.

Evaluating tranexamic acid for the prevention and treatment of obstetric hemorrhage.

PURPOSE OF REVIEW: Tranexamic acid (TXA) has emerged as a promising pharmacological adjunct to treat and prevent postpartum hemorrhage (PPH). We provide an overview of TXA, including its pharmacology, key findings of randomized trials and observational studies, and critical patient safety information. RECENT FINDINGS: Pharmacokinetic data indicate that TXA infusions result in peak plasma concentration within 3 min (range: 1-6.6 min). Ex-vivo pharmacodynamic data suggest that low-dose TXA (5 mg/kg) inhibits maximum lysis for at least 1 h. In predominantly developing countries, TXA has demonstrated a 19% reduction in the risk of bleeding-related death among patients with PPH. Based on high-quality randomized trials, TXA prophylaxis does not effectively reduce the risk of PPH during vaginal delivery and is likely ineffective in reducing the PPH risk during cesarean delivery. TXA exposure does not increase the risk of maternal thrombotic events. Maternal deaths have occurred from accidental intrathecal TXA injection from look-alike medication errors. SUMMARY: TXA has shown promise as an important adjunct for PPH treatment, especially in low-resource settings. However, TXA is not recommended as PPH prophylaxis during vaginal or cesarean delivery. Patient safety initiatives should be prioritized to prevent maternal death from accidental intrathecal TXA injection.

Early Postpartum Hospital Encounters among Patients with Genitourinary and Wound Infections during Hospitalization for Birth.

OBJECTIVES: This study aimed to assess the associations between genitourinary and wound infections during the birth hospitalization and early postpartum hospital encounters, and to evaluate clinical risk factors for early postpartum hospital encounters among patients with genitourinary and wound infections during the birth hospitalization. STUDY DESIGN: We conducted a population-based cohort study of births in California during 2016 to 2018 and postpartum hospital encounters. We identified genitourinary and wound infections using diagnosis codes. Our main outcome was early postpartum hospital encounter, defined as a readmission or emergency department (ED) visit within 3 days after discharge from the birth hospitalization. We evaluated the association of genitourinary and wound infections (overall and subtypes) with early postpartum hospital encounter using logistic regression, adjusting for sociodemographic factors and comorbidities and stratified by mode of birth. We then evaluated factors associated with early postpartum hospital encounter among patients with genitourinary and wound infections. RESULTS: Among 1,217,803 birth hospitalizations, 5.5% were complicated by genitourinary and wound infections. Genitourinary or wound infection was associated with an early postpartum hospital encounter among patients with both vaginal births (2.2%; adjusted risk ratio [aRR[: 1.26; 95% confidence interval [CI]: 1.17-1.36) and cesarean births (3.2%; aRR: 1.23; 95% CI: 1.15-1.32). Patients with a cesarean birth and a major puerperal infection or wound infection had the highest risk of an early postpartum hospital encounter (6.4 and 4.3%, respectively). Among patients with genitourinary and wound infections during the birth hospitalization, factors associated with an early postpartum hospital encounter included severe maternal morbidity, major mental health condition, prolonged postpartum hospital stay, and, among cesarean births, postpartum hemorrhage (p-value < 0.05). CONCLUSION: Genitourinary and wound infections during hospitalization for birth may increase risk of a readmission or ED visit within the first few days after discharge, particularly among patients who have a cesarean birth and a major puerperal infection or wound infection. KEY POINTS: · In all, 5.5% of patients giving birth had a genitourinary or wound infection (GWI).. · A total of 2.7% of GWI patients had a hospital encounter within 3 days of discharge after birth.. · Major puerperal infection and wound infection had the highest risk of an early hospital encounter.. · Among GWI patients, several birth complications were associated with an early hospital encounter..

Knowledge Gaps in Placenta Accreta Spectrum.

Since its first description early in the 20th Century, placenta accreta and its variants have changed substantially in incidence, risk factor profile, clinical presentation, diagnosis and management. While systematic use of diagnostic tools and a multidisciplinary team care approach has begun to improve patient outcomes, the condition's pathophysiology, epidemiology, and best practices for diagnosis and management remain poorly understood. The use of large databases with broadly accepted terminology and diagnostic criteria should accelerate research in this area. Future work should focus on non-traditional phenotypes, such as those without placenta previa-preventive strategies, and long term medical and emotional support for patients facing this diagnosis. KEY POINTS: · Placenta accreta spectrum research may be improved with standardized terminology and use of large databases.. · Placenta accreta prediction should move beyond ultrasound with the addition of biomarkers, and needs to extend to those without traditional risk factors.. · Future research should identify practices that can prevent future accreta development..

Hospital-level variation in rates of postpartum hemorrhage in California.

BACKGROUND: To examine the extent of hospital-level variation in risk-adjusted rates of postpartum hemorrhage (PPH). STUDY DESIGN AND METHODS: We performed a cross-sectional study examining live births in 257 California hospitals between 2011 and 2015 using linked birth certificate and maternal discharge data. PPH was measured using International Classification of Diseases Codes version 9. Mixed-effects logistic regression models were used to examine the presence and extent of hospital-level variation in PPH before and after adjustment for patient-level risk factors and select hospital characteristics (teaching status and annual delivery volume). Risk-adjusted rates of PPH were estimated for each hospital. The extent of hospital variation was evaluated using the median odds ratio (MOR) and intraclass correlation coefficient (ICC). RESULTS: Our study cohort comprised 1,904,479 women who had a live birth delivery hospitalization at 247 hospitals. The median, lowest, and highest hospital-specific rates of PPH were 3.48%, 0.54%, and 12.0%, respectively. Similar rates were observed after adjustment for patient and hospital factors (3.44%, 0.60%, and 11.48%). After adjustment, the proportion of the total variation in PPH rates attributable to the hospital was low, with a MOR of 2.02 (95% confidence interval [CI]: 1.89-2.15) and ICC of 14.3% (95% CI: 11.9%-16.3%). DISCUSSION: Wide variability exists in the rate of PPH across hospitals in California, not attributable to patient factors, hospital teaching status, and hospital annual delivery volume. Determining whether differences in hospital quality of care explain the unaccounted-for variation in hospital-level PPH rates should be a public health priority.

Subsequent risk of stillbirth, preterm birth, and small for gestational age: A cross-outcome analysis of adverse birth outcomes.

BACKGROUND: Stillbirth, preterm birth, and small for gestational age (SGA) birth have an increased recurrence risk. The occurrence of one of these biologically related outcomes could also increase the risk for another one of these outcomes in a subsequent pregnancy. OBJECTIVES: We assessed cross-outcome risks for subsequent stillbirth, preterm birth, and SGA. METHODS: We used live birth and fetal death records to identify singleton, sequential birth pairs in California (1997-2017). Stillbirth was defined as delivery at ≥20 weeks of gestation of a foetus that died in utero; preterm birth as live birth at 20-36 weeks; and small for gestational age as sex-specific birthweight <10th percentile for gestational age. Risk ratios (RR) were computed using modified Poisson regression and adjusted for potential confounders. Sensitivity analyses included analysing a cohort restricted to primiparous index births and using inverse-probability censoring weights. RESULTS: Of 3,108,532 birth pairs, 16,668 (0.5%), 260,596 (8.4%) and 331,109 (10.7%) of index births were stillborn, preterm and SGA, respectively. Among individuals with an index stillbirth, the adjusted RRs were 1.90 (95% confidence interval [CI] 1.83, 1.98) for subsequent preterm and 1.35 (95% CI 1.28, 1.41) for subsequent SGA. Among those with index preterm birth, the adjusted RRs were 2.02 (95% CI 1.92, 2.13) for stillbirth and 1.42 (95% CI 1.41, 1.44) for SGA. Among those with index SGA, the adjusted RRs were 1.54 (95% CI 1.46, 1.63) for stillbirth and 1.45 (95% CI 1.44, 1.47) for preterm birth. Similar results were reported for sensitivity analyses. CONCLUSIONS: Individuals experiencing stillbirth, preterm birth, or SGA in one pregnancy had an increased risk of one of these biologically related outcomes in a subsequent pregnancy. These findings could encourage enhanced surveillance for individuals who experience stillbirth, preterm birth, or SGA and desire a subsequent pregnancy.

Epidural labour analgesia and autism spectrum disorder: is the current evidence sufficient to dismiss an association?

Findings from a population-based study using a sibling-matched analysis published in this issue of the British Journal of Anaesthesia indicate that epidural labour analgesia is not associated with an increased risk of autism spectrum disorder. These findings are consistent with those from three other population-based studies that used similar methodological approaches. Cumulatively, these robust, high-quality epidemiological data support the assertion that there is no meaningful association between epidural labour analgesia and autism spectrum disorder in offspring.

Association of Medicaid Expansion With Neuraxial Labor Analgesia Use in the United States: A Retrospective Cross-Sectional Analysis.

BACKGROUND: The Affordable Care Act has been associated with increased Medicaid coverage for childbirth among low-income US women. We hypothesized that Medicaid expansion was associated with increased use of labor neuraxial analgesia. METHODS: We performed a cross-sectional analysis of US women with singleton live births who underwent vaginal delivery or intrapartum cesarean delivery between 2009 and 2017. Data were sourced from births in 26 US states that used the 2003 Revised US Birth Certificate. Difference-in-difference linear probability models were used to compare changes in the prevalence of neuraxial labor analgesia in 15 expansion and 11 nonexpansion states before and after Medicaid expansion. Models were adjusted for potential maternal and obstetric confounders with standard errors clustered at the state level. RESULTS: The study sample included 5,703,371 births from 15 expansion states and 5,582,689 births from 11 nonexpansion states. In the preexpansion period, the overall rate of neuraxial analgesia in expansion and nonexpansion states was 73.2% vs 76.3%. Compared with the preexpansion period, the rate of neuraxial analgesia increased in the postexpansion period by 1.7% in expansion states (95% CI, 1.6-1.8) and 0.9% (95% CI, 0.9-1.0) in nonexpansion states. The adjusted difference-in-difference estimate comparing expansion and nonexpansion states was 0.47% points (95% CI, -0.63 to 1.57; P = .39). CONCLUSIONS: Medicaid expansion was not associated with an increase in the rate of neuraxial labor analgesia in expansion states compared to the change in nonexpansion states over the same time period. Increasing Medicaid eligibility alone may be insufficient to increase the rate of neuraxial labor analgesia.

Update on Applications and Limitations of Perioperative Tranexamic Acid.

Tranexamic acid (TXA) is a potent antifibrinolytic with documented efficacy in reducing blood loss and allogeneic red blood cell transfusion in several clinical settings. With a growing emphasis on patient blood management, TXA has become an integral aspect of perioperative blood conservation strategies. While clinical applications of TXA in the perioperative period are expanding, routine use in select clinical scenarios should be supported by evidence for efficacy. Furthermore, questions regarding optimal dosing without increased risk of adverse events such as thrombosis or seizures should be answered. Therefore, ongoing investigations into TXA utilization in cardiac surgery, obstetrics, acute trauma, orthopedic surgery, neurosurgery, pediatric surgery, and other perioperative settings continue. The aim of this review is to provide an update on the current applications and limitations of TXA use in the perioperative period.

Placenta Accreta Spectrum Disorders: Knowledge Gaps in Anesthesia Care.

Placenta accreta spectrum (PAS) disorder is a potentially life-threatening condition that can occur during pregnancy. PAS puts pregnant individuals at a very high risk of major blood loss, hysterectomy, and intensive care unit admission. These patients should receive care in a center with multidisciplinary experience and expertise in managing PAS disorder. Obstetric anesthesiologists play vital roles in the peripartum care of pregnant patients with suspected PAS. As well as providing high-quality anesthesia care, obstetric anesthesiologists coordinate peridelivery care, drive transfusion-related decision making, and oversee postpartum analgesia. However, there are a number of key knowledge gaps related to the anesthesia care of these patients. For example, limited data are available describing optimal anesthesia staffing models for scheduled and unscheduled delivery. Evidence and consensus are lacking on the ideal surgical location for delivery; primary mode of anesthesia for cesarean delivery; preoperative blood ordering; use of pharmacological adjuncts for hemorrhage management, such as tranexamic acid and fibrinogen concentrate; neuraxial blocks and abdominal wall blocks for postoperative analgesia; and the preferred location for postpartum care. It is also unclear how anesthesia-related decision making and interventions impact physical and mental health outcomes. High-quality international multicenter studies are needed to fill these knowledge gaps and advance the anesthesia care of patients with PAS.

Association between Neuraxial Labor Analgesia and Neonatal Morbidity after Operative Vaginal Delivery.

BACKGROUND: Up to 84% of women who undergo operative vaginal delivery receive neuraxial analgesia. However, little is known about the association between neuraxial analgesia and neonatal morbidity in women who undergo operative vaginal delivery. The authors hypothesized that neuraxial analgesia is associated with a reduced risk of neonatal morbidity among women undergoing operative vaginal delivery. METHODS: Using United States birth certificate data, the study identified women with singleton pregnancies who underwent operative vaginal (forceps- or vacuum-assisted delivery) in 2017. The authors examined the relationships between neuraxial labor analgesia and neonatal morbidity, the latter defined by any of the following: 5-min Apgar score less than 7, immediate assisted ventilation, assisted ventilation greater than 6 h, neonatal intensive care unit admission, neonatal transfer to a different facility within 24 h of delivery, and neonatal seizure or serious neurologic dysfunction. The authors accounted for sociodemographic and obstetric factors as potential confounders in their analysis. RESULTS: The study cohort comprised 106,845 women who underwent operative vaginal delivery, of whom 92,518 (86.6%) received neuraxial analgesia. The proportion of neonates with morbidity was higher in the neuraxial analgesia group than the nonneuraxial group (10,409 of 92,518 [11.3%] vs. 1,271 of 14,327 [8.9%], respectively; P < 0.001). The unadjusted relative risk was 1.27 (95% CI, 1.20 to 1.34; P < 0.001); after accounting for confounders using a multivariable model, the adjusted relative risk was 1.19 (95% CI, 1.12 to 1.26; P < 0.001). In a post hoc analysis, after excluding neonatal intensive care unit admission and neonatal transfer from the composite outcome, the effect of neuraxial analgesia on neonatal morbidity was not statistically significant (adjusted relative risk, 1.07; 95% CI, 1.00 to 1.16; P = 0.054). CONCLUSIONS: In this population-based cross-sectional study, a neonatal benefit of neuraxial analgesia for operative vaginal delivery was not observed. Confounding by indication may explain the observed association between neuraxial analgesia and neonatal morbidity, however this dataset was not designed to evaluate such considerations.

Association of Gestational Age with Postpartum Hemorrhage: An International Cohort Study.

BACKGROUND: Risk factors for postpartum hemorrhage, such as chorioamnionitis and multiple gestation, have been identified in previous epidemiologic studies. However, existing data describing the association between gestational age at delivery and postpartum hemorrhage are conflicting. The aim of this study was to assess the association between gestational age at delivery and postpartum hemorrhage. METHODS: The authors conducted a population-based retrospective cohort study of women who underwent live birth delivery in Sweden between 2014 and 2017 and in California between 2011 and 2015. The primary exposure was gestational age at delivery. The primary outcome was postpartum hemorrhage, classified using International Classification of Diseases, Ninth Revision-Clinical Modification codes for California births and a blood loss greater than 1,000 ml for Swedish births. The authors accounted for demographic and obstetric factors as potential confounders in the analyses. RESULTS: The incidences of postpartum hemorrhage in Sweden (23,323/328,729; 7.1%) and in California (66,583/2,079,637; 3.2%) were not comparable. In Sweden and California, the incidence of postpartum hemorrhage was highest for deliveries between 41 and 42 weeks' gestation (7,186/75,539 [9.5%] and 8,921/160,267 [5.6%], respectively). Compared to deliveries between 37 and 38 weeks, deliveries between 41 and 42 weeks had the highest adjusted odds of postpartum hemorrhage (1.62 [95% CI, 1.56 to 1.69] in Sweden and 2.04 [95% CI, 1.98 to 2.09] in California). In both cohorts, the authors observed a nonlinear (J-shaped) association between gestational age and postpartum hemorrhage risk, with 39 weeks as the nadir. In the sensitivity analyses, similar findings were observed among cesarean deliveries only, when postpartum hemorrhage was classified only by International Classification of Diseases, Tenth Revision-Clinical Modification codes, and after excluding women with abnormal placentation disorders. CONCLUSIONS: The postpartum hemorrhage incidence in Sweden and California was not comparable. When assessing a woman's risk for postpartum hemorrhage, clinicians should be aware of the heightened odds in women who deliver between 41 and 42 weeks' gestation.

Maternal Health after Stillbirth: Postpartum Hospital Readmission in California.

OBJECTIVE: The aim of this study is to assess whether the risk of postpartum readmission within 6 weeks of giving birth differs for women who had stillbirths compared with live births. STUDY DESIGN: Using data from the Office of Statewide Health Planning and Development in California, we performed a population-based cohort study of 7,398,640 births between 1999 and 2011. We identified diagnoses and procedures associated with the first postpartum hospital readmission that occurred within 6 weeks after giving birth. We used log-binomial models to estimate relative risk (RR) of postpartum readmission for women who had stillbirth compared with live birth deliveries, adjusting for maternal demographic, prepregnancy, pregnancy, and delivery characteristics. RESULTS: The rate of postpartum readmission was higher among women who had stillbirths compared with women who had live births (206 and 96 per 10,000 births, respectively). After adjusting for maternal demographic and medical characteristics, the risk of postpartum readmission for women who had stillbirths was nearly 1.5 times greater (adjusted RR = 1.47, 95% confidence interval: 1.35-1.60) compared with live births. Among women with stillbirths, the most common indications at readmission were uterine infection or pelvic inflammatory disease, psychiatric conditions, hypertensive disorder, and urinary tract infection. CONCLUSION: Based on our findings, women who have stillbirths are at higher risk of postpartum readmissions within 6 weeks of giving birth than women who have live births. Women who have stillbirths may benefit from additional monitoring and counseling after hospital discharge for potential postpartum medical and psychiatric complications. KEY POINTS: · Women who have stillbirths are at nearly 1.5 times greater risk of postpartum readmission than women who have live births.. · Uterine infections and pelvic inflammatory disease, and psychiatric conditions are the most common reasons for readmission among women who had a stillbirth.. · Women who have stillbirths may benefit from additional monitoring and counseling after hospital discharge for potential postpartum medical and psychiatric complications..

Maternal and Infant Adverse Outcomes Associated with Mild and Severe Preeclampsia during the First Year after Delivery in the United States.

OBJECTIVE: The burden of preeclampsia severity on the health of mothers and infants during the first year after delivery is unclear, given the lack of population-based longitudinal studies in the United States. STUDY DESIGN: We assessed maternal and infant adverse outcomes during the first year after delivery using population-based hospital discharge information merged with vital statistics and birth certificates of 2,021,013 linked maternal-infant births in California. We calculated sampling weights using the National Center for Health Statistics data to adjust for observed differences in maternal characteristics between California and the rest of the United States. Separately, we estimated the association between preeclampsia and gestational age and examined collider bias in models of preeclampsia and maternal and infant adverse outcomes. RESULTS: Compared with women without preeclampsia, women with mild and severe preeclampsia delivered 0.66 weeks (95% confidence interval [CI]: 0.64, 0.68) and 2.74 weeks (95% CI: 2.72, 2.77) earlier, respectively. Mild preeclampsia was associated with an increased risk of having any maternal adverse outcome (relative risk [RR] = 1.95; 95% CI: 1.93, 1.97), as was severe preeclampsia (RR = 2.80; 95% CI: 2.78, 2.82). The risk of an infant adverse outcome was increased for severe preeclampsia (RR = 2.15; 95% CI: 2.14, 2.17) but only marginally for mild preeclampsia (RR = 0.99; 95% CI: 0.98, 1). Collider bias produced an inverse association for mild preeclampsia and attenuated the association for severe preeclampsia in models for any infant adverse outcome. CONCLUSION: Using multiple datasets, we estimated that severe preeclampsia is associated with a higher risk of maternal and infant adverse outcomes compared with mild preeclampsia, including an earlier preterm delivery.

Assessing the Association Between Blood Loss and Postoperative Hemoglobin After Cesarean Delivery: A Prospective Study of 4 Blood Loss Measurement Modalities.

BACKGROUND: Visual estimation and gravimetric methods are commonly used to quantify the volume of blood loss during cesarean delivery (CD). However, the correlation between blood loss and post-CD hemoglobin (Hb) is poorly studied, and it is unclear whether the correlation varies according to how blood loss is measured. METHODS: After obtaining Institutional Review Board approval, we performed a prospective study of 61 women undergoing CD to assess the relations between post-CD Hb and blood loss measured using 4 modalities: gravimetric blood loss measurement (gBL), visual blood loss estimation by a blinded obstetrician (oBL) and anesthesiologist (aBL), and the Triton System (tBL). Hb was measured preoperatively and within 10 minutes after CD. gBL was quantified as blood volume in a suction canister in addition to the weight of blood-soaked sponges. tBL was measured with the Triton System by photographing blood-soaked sponges and suction canister contents. To assess the relation between blood loss and post-CD Hb, we performed correlation analyses and compared the magnitude of the correlations across the 4 measurement modalities using William t test. A Bonferroni correction was set to identify a statistically significant correlation (P < .0125) and statistically significant differences between correlation coefficients (P < .008). RESULTS: The mean (standard deviation) preoperative Hb was 12 (1.1) g/dL and post-CD Hb was 11.3 (1.0) g/dL. Median (interquartile range) values for gBL, oBL, aBL, and tBL were 672 mL (266-970), 700 mL (600-800), 750 mL (600-1000), and 496 mL (374-729), respectively. A statistically significant but weak correlation was observed between tBL and post-CD Hb (r = -0.33; P = .01). No statistically significant correlations were observed among aBL (r = -0.25; P = .06), oBL (r = -0.2; P = .13), and gBL (r = -0.3; P = .03) with post-CD Hb. We did not detect any significant differences between any 2 correlation coefficients across the 4 modalities. CONCLUSIONS: Given that we observed only weak correlations between each modality with post-CD Hb and no significant differences in the magnitude of the correlations across the 4 modalities, there may be limited clinical utility in estimating post-CD Hb from blood loss values measured with any of the 4 modalities.

Accuracy of international classification of diseases, ninth revision, codes for postpartum hemorrhage among women undergoing cesarean delivery.

BACKGROUND: Determining the accuracy of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9) codes for postpartum hemorrhage (PPH) is vital for reaching valid conclusions about the epidemiology of PPH. Our primary objectives were to assess the performance characteristics of ICD-9 PPH codes against a reference standard using estimated blood loss (EBL) among a cohort undergoing Cesarean delivery. STUDY DESIGN AND METHODS: We analyzed maternal discharge and EBL data from women who underwent Cesarean delivery at Kaiser Permanente Northern California facilities between 2010 and 2013. We defined PPH as an EBL of at least 1000 mL. In a secondary analysis, ICD-9 performance characteristics were assessed using an EBL of at least 1500 mL to classify severe PPH. RESULTS: We identified 35,614 hospitalizations for Cesarean delivery. Using EBL of at least 1000 mL as the "gold standard," PPH codes had a sensitivity of 27.8%, specificity of 97%, positive predictive value (PPV) of 74.5%, and a negative predictive value (NPV) of 80.9%. The prevalence of a PPH code (9%) was lower than the prevalence using a blood loss of at least 1000 mL (24%). Using a reference standard of EBL of at least 1500 mL, PPH codes had a sensitivity of 61.7%, specificity of 93.8%, PPV of 34.2%, and NPV of 97.9%. CONCLUSION: PPH ICD-9 codes have high specificity, moderately high PPVs and NPVs, and low sensitivity. An EBL of at least 1500 mL as a reference standard has higher sensitivity. Our findings suggest that, for women undergoing Cesarean delivery, quality improvement efforts are needed to enhance PPH ICD-9 coding accuracy in administrative data sets.

Maternal Body Mass Index and Use of Labor Neuraxial Analgesia: A Population-based Retrospective Cohort Study.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: Neuraxial labor analgesia may benefit obese women by optimizing cardiorespiratory function and mitigating complications related to emergency general anesthesia. We hypothesized that obese women have a higher rate of neuraxial analgesia compared with nonobese parturients. METHODS: Using U.S. natality data, our cohort comprised 17,220,680 deliveries, which accounts for 61.5% of 28 million births in the United States between 2009 and 2015. We examined the relationships between body mass index class and neuraxial labor analgesia, adjusting for sociodemographic, antenatal, pregnancy, and peripartum factors. RESULTS: The study cohort comprised 17,220,680 women; 0.1% were underweight, 12.7% were normal body mass index, 37% were overweight, and 28.3%, 13.5%, and 8.4% were obesity class I, II, and III, respectively. Rates of neuraxial analgesia by body mass index class were as follows: underweight, 59.7% (9,030/15,128); normal body mass index, 68.1% (1,487,117/2,182,797); overweight, 70.3% (4,476,685/6,368,656); obesity class I, 71.8% (3,503,321/4,881,938); obesity class II, 73.4% (1,710,099/2,330,028); and obesity class III, 75.6% (1,089,668/1,442,133). Compared to women with normal body mass index, the likelihood of receiving neuraxial analgesia was slightly increased for overweight women (adjusted relative risk, 1.02; 95% CI, 1.02 to 1.02), obese class I (adjusted relative risk, 1.04; 95% CI, 1.04 to 1.04), obese class II (adjusted relative risk, 1.05; 95% CI, 1.05 to 1.05), and obese class III (adjusted relative risk, 1.06; 95% CI, 1.06 to 1.06). CONCLUSIONS: Our findings suggest that the likelihood of receiving neuraxial analgesia is only marginally increased for morbidly obese women compared to women with normal body mass index.

Effect of Maternal Body Mass Index on Postpartum Hemorrhage.

BACKGROUND: It is unclear whether obesity is a risk factor for postpartum hemorrhage. The authors hypothesized that obese women are at greater risk of hemorrhage than women with a normal body mass index. METHODS: The authors conducted a cohort study of women who underwent delivery hospitalization in California between 2008 and 2012. Using multilevel regression, the authors examined the relationships between body mass index with hemorrhage (primary outcome), atonic hemorrhage, and severe hemorrhage (secondary outcomes). Stratified analyses were performed according to delivery mode. RESULTS: The absolute event rate for hemorrhage was 60,604/2,176,673 (2.8%). In this cohort, 4% of women were underweight, 49.1% of women were normal body mass index, 25.9% of women were overweight, and 12.7%, 5.2%, and 3.1% of women were in obesity class I, II, and III, respectively. Compared to normal body mass index women, the odds of hemorrhage and atonic hemorrhage were modestly increased for overweight women (hemorrhage: adjusted odds ratio [aOR], 1.06; 99% CI, 1.04 to 1.08; atonic hemorrhage: aOR, 1.07; 99% CI, 1.05 to 1.09) and obesity class I (hemorrhage: aOR, 1.08; 99% CI, 1.05 to 1.11; atonic hemorrhage; aOR, 1.11; 99% CI, 1.08 to 1.15). After vaginal delivery, overweight and obese women had up to 19% increased odds of hemorrhage or atonic hemorrhage; whereas, after cesarean delivery, women in any obesity class had up to 14% decreased odds of severe hemorrhage. CONCLUSIONS: The authors' findings suggest that, at most, maternal obesity has a modest effect on hemorrhage risk. The direction of the association between hemorrhage and body mass index may differ by delivery mode.