Increased length of active labor is associated with adverse perinatal outcomes among nulliparous women undergoing labor induction.

OBJECTIVE: Evaluate the association between current recommendations for active labor duration in nulliparous women undergoing labor induction and adverse perinatal outcomes. STUDY DESIGN: Retrospective cohort study from 2012 to 2015. Subjects were nulliparous, 18-44 years, cephalic, singleton ≥37 weeks undergoing labor induction who reached active labor. We created three subgroups, defined by active labor duration from 6 to 10cm as < the median, median-95th percentile, and >95th percentile based on contemporary labor curves. We evaluated the association between subgroups and cesarean delivery, chorioamnionitis, blood loss (EBL), 5-minute Apgar score < 7, and neonatal intensive care unit (NICU) admission using logistic regression. RESULTS: Among 356 women, 34.8% had an active labor duration < median, 43.3% were between the median-95th percentile, and 21.9% were >95th percentile. The risk of cesarean delivery increased with longer active labor duration; 1.8-fold (95%CI = 1.1-3.1) and 4.0-fold (95%CI = 2.5-6.5) for women whose active labors were between the median-95th percentile and >95th percentile, respectively. Chorioamnionitis increased by 3.9-fold (95%CI = 1.2-13.2) in the >95th percentile subgroup. Active labor length was not associated with EBL, Apgar scores, or NICU admission. CONCLUSIONS: Cesarean delivery and chorioamnionitis increased significantly as induced active labor duration exceeded the median. This study provides a better understanding regarding the risks of longer active labor as defined by contemporary labor curves.

Contribution of hypertension to severe maternal morbidity.

BACKGROUND: Maternal mortality and severe maternal morbidity are growing public health concerns in the United States. The Centers for Disease Control and Prevention Severe Maternal Morbidity measure provides insight into processes underlying maternal mortality and may highlight modifiable risk factors for adverse maternal health outcomes. OBJECTIVE: The primary objective of this study was to evaluate the association between hypertensive disorders and severe maternal morbidity at a regional perinatal referral center. We hypothesized that women with preeclampsia with severe features would have a higher rate of severe maternal morbidity compared to normotensive women. We also assessed the proportion of severe maternal morbidity diagnoses that were present on admission, in contrast to those arising during the delivery hospitalization. STUDY DESIGN: In this retrospective cross-sectional analysis, we assessed rates of severe maternal morbidity diagnoses (eg, renal insufficiency, shock, and sepsis) and procedures (eg, transfusion and hysterectomy) for all 7025 women who delivered at the University of Washington Medical Center from Oct. 1, 2013, through May 31, 2017. Severe maternal morbidity was determined from prespecified International Classification of Diseases diagnosis and procedure codes; all diagnoses were confirmed by chart review. Present-on-admission rates were calculated for each diagnosis through hospital administrative data provided by the Vizient University Health System Consortium. Maternal demographic and clinical characteristics were compared for women with and without severe maternal morbidity. The χ2 and Fisher exact tests were used to determine statistical significance. Odds ratios and 95% confidence intervals were calculated for the associations between maternal demographic and clinical characteristics and severe maternal morbidity. RESULTS: Of 7025 deliveries, 284 (4%) had severe maternal morbidity; 154 had transfusion only, 27 had other procedures, and 103 women had 149 severe maternal morbidity diagnoses (26 women had multiple diagnoses). Severe preeclampsia occurred in 438 deliveries (6.2%). Notably, hypertension was associated with severe maternal morbidity in a dose-dependent fashion, with the strongest association observed for preeclampsia with severe features (odds ratio, 5.4; 95% confidence interval, 3.9-7.3). Severe maternal morbidity was also significantly associated with preeclampsia without severe features, chronic hypertension, preterm delivery, pregestational diabetes, and multiple gestation. Among women with severe maternal morbidity, over one third of preterm births were associated with maternal hypertension. American Indian/Alaskan Native women had significantly higher severe maternal morbidity rates compared to other racial/ethnic groups (11.7% vs 3.9% for Whites, P < .01). Overall, 39.6% of severe maternal morbidity diagnoses were present on admission. CONCLUSION: Hypertensive disorders in pregnancy are strongly associated with severe maternal morbidity in a dose-dependent relationship, suggesting that strategies to address rising maternal morbidity rates should include early recognition and management of hypertension. Prevention strategies focused on hypertension might also impact medically indicated preterm deliveries. The finding of increased severe maternal morbidity among American Indian/Alaskan Native women, a disadvantaged population in Washington State, underscores the role that socioeconomic factors may play in adverse maternal health outcomes. As 39% of severe maternal morbidity diagnoses were present on admission, this measure should be risk-adjusted if used as a quality metric for comparison between hospitals.

Duration of Spontaneous Active Labor and Perinatal Outcomes Using Contemporary Labor Curves.

OBJECTIVE: Evaluate the association between spontaneous active labor duration utilizing contemporary labor curves and risk of adverse outcomes. MATERIALS AND METHODS: This is a retrospective cohort study from January 2012 to January 2015. Subjects were nulliparous, 18 to 44 years, with a cephalic, singleton ≥37 weeks in spontaneous labor. Subjects were placed into three subgroups, defined by active labor duration from 6 to 10 cm as less than the median, the median-95th, and >95th percentile based on contemporary labor curves published by Zhang et al. We evaluated the association between subgroups and cesarean delivery, chorioamnionitis, estimated blood loss, Apgar score < 7 at 5 minutes, and neonatal intensive care unit admission using logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Six-hundred forty two women met the inclusion criteria. Compared with women whose active labor was less than the median, the risk of cesarean was higher in the median-95th percentile ([adjusted OR, aOR] 3.1, 95% CI 1.8-5.5) and the >95th percentile ([aOR] 6.8, 95% CI 3.9-11.7) subgroups. There was an increased odds of chorioamnionitis in the median-95th percentile subgroup ([aOR] 2.5, 95% CI 1.1-5.9). CONCLUSION: Chorioamnionitis and cesarean delivery increased significantly as labor duration exceeded the median. This study provides a better understanding regarding the potential risk of cesarean and chorioamnionitis using contemporary labor curves.

A Comparison of the Nulliparous-Term-Singleton-Vertex and Society of Maternal-Fetal Medicine Cesarean Birth Metrics Based on Hospital Size.

OBJECTIVE: The purpose of this study was to compare the nulliparous-term-singleton-vertex (NTSV) and the Society of Maternal-Fetal Medicine (SMFM) cesarean birth metrics as tools for quality improvement efforts based on hospital size. MATERIALS AND METHODS: Cesarean birth rates from 275 hospitals from six states were used to evaluate the NTSV metric and 81 hospitals from four states for the SMFM metric. Data were assessed based on delivery volume, their use as an effective tool for ongoing quality improvement programs, and their ability to serve as performance-based payline indicators. RESULTS: The average NTSV and SMFM cesarean birth rates were 25.6 and 13.0%, respectively. The number of deliveries included in the NTSV metric was stable across all hospital sizes (33.1-36.2%). With the SMFM metric, there was a progressive decline in the number of deliveries included, 90.0 versus 69.6%, in relatively small to large facilities. Variability was less and precision increased with the SMFM metric, which reduced the number of hospitals that could be incorrectly categorized when using performance-based predefined cesarean birth rate paylines. CONCLUSION: The SMFM metric appears to be better suited as a tool for rapid process improvement programs aimed at reducing cesarean birth rates in low-risk patients.

Effect of severity of illness on cesarean delivery rates in Washington State.

BACKGROUND: Hospitals and providers are increasingly held accountable for their cesarean delivery rates. In the perinatal quality improvement arena, there is vigorous debate about whether all hospitals can be held to the same benchmark for an acceptable cesarean rate regardless of patient acuity. However, the causes of variation in hospital cesarean delivery rates are not well understood. OBJECTIVE: We sought to evaluate the association and temporal trends between severity of illness at admission and the primary term singleton vertex cesarean delivery rate among hospitals in Washington State. We hypothesized that hospitals with higher patient acuity would have higher cesarean delivery rates and that this pattern would persist over time. STUDY DESIGN: In this cross-sectional analysis, we analyzed aggregate hospital-level data for all nonmilitary hospitals in Washington State with ≥100 deliveries/y during federal fiscal years 2010 through 2014 (287,031 deliveries). Data were obtained from the Washington State Comprehensive Hospital Abstract Reporting System, which includes inpatient demographic, diagnosis, procedure, and discharge information derived from hospital billing systems. Age, admission diagnoses and procedure codes were converted to patient-level admission severity-of-illness scores using the All Patient Refined Diagnosis Related Groups classification system. This system is widely used throughout the United States to adjust hospital data for severity of illness. Mean admission hospital-level severity-of-illness scores were calculated for each fiscal year among the term singleton vertex population with no history of cesarean delivery. We used linear regression to evaluate the association between hospital admission severity of illness and the primary term singleton vertex cesarean delivery rate, calculated Pearson correlation coefficients, and compared regression line slopes and 95% confidence intervals for each fiscal year. RESULTS: Hospitals were diverse with respect to delivery volume, level of care, and geographic location within Washington. Hospital aggregate admission severity-of-illness score correlated with primary term singleton vertex cesarean delivery rate in all fiscal years (R2 0.38-0.58, P < .001). For every year in the study interval, as admission severity of illness increased so did the primary term singleton vertex cesarean rate. The slope of the regression line decreased during the study interval, suggesting that statewide decrease in primary term singleton vertex cesarean rate occurred across the range of severity of illness. CONCLUSION: Admission severity-of-illness score is strongly associated with the primary term singleton vertex cesarean delivery rate among hospitals in Washington State. Approximately 50% of variation in hospital primary term singleton vertex cesarean delivery rates appeared to be related to admission severity of illness. This relationship persisted over time despite a statewide decrease in cesarean delivery, suggesting that patient acuity will likely continue to contribute to hospital variation in cesarean delivery rates despite perinatal quality improvement efforts. The major implication of this study is that patient acuity should be considered when determining optimal cesarean delivery rates. High-acuity hospitals are likely to have high cesarean rates because they provide a specific role in serving regional needs. To hold these centers to an arbitrary benchmark may jeopardize the funding necessary to support regional safety net institutions.

Beyond the Ivory Tower: A Comparison of Grades Across Academic and Community OB/GYN Clerkship Sites.

UNLABELLED: CONSTRUCT: Decentralized clinical education is the use of community facilities and community physicians to educate medical students. The theory behind decentralized clinical education is that academic and community sites will provide educational equivalency as determined by objective and subjective performance measures, while training more medical students and exposing students to rural or underserved communities. One of the major challenges of decentralized clinical education is ensuring site comparability in both learning opportunities and evaluation of students. BACKGROUND: Previous research has examined objective measures of student performance, but less is known about subjective performance measures, particularly in the field of obstetrics and gynecology (OB/GYN). This study explores the implications of clinical site on the adequacy of subjective and objective performance measures. APPROACH: This was a retrospective cohort study of 801 students in the University of Washington School of Medicine OB/GYN clerkship from 2008 to 2012. Academic sites included those with OB/GYN residency programs (n = 2) and community sites included those without residency programs (n = 29). The association between clerkship site and National Board of Medical Examiners (NBME) grade was assessed using linear regression and clinical and final grade using multinomial regression, estimating ß coefficient and relative risks (RR), respectively, and 95% confidence intervals (CIs), adjusting for gender, academic quarter of clerkship, and year of clerkship. RESULTS: There were no differences in NBME exam grades of students at academic sites (76.4 (7.3) versus 74.6 (8.0), ß = -0.11, 95% CI [1.35, 1.12] compared to community sites. For clinical grade, students at community sites were 2.4 times more likely to receive honors relative to high pass (RR 2.45), 95% CI [1.72, 3.50], and for final grade, students at community sites were 1.9 times more likely to receive honors relative to pass (RR 1.98), 95% CI [1.27, 3.09], and 1.6 times more likely to receive honors relative to high pass (RR 1.62), 95% CI [1.05, 2.50], compared to those at academic sites. CONCLUSIONS: Students at community sites receive higher clinical and final grades in the OB/GYN clerkship. This highlights a significant challenge in decentralized clinical education-ensuring site comparability in clinical grading, Further work should examine the differences in sites, as well as improve standardization of clinical grading. This also underscores an important consideration, as the final grade can influence medical school rank, nomination into honor societies, and ranking of residency applicants.

Bakri balloon effectiveness for postpartum hemorrhage: a "real world experience".

INTRODUCTION: The Bakri balloon has been advocated for management of obstetric hemorrhage, based on several small studies (2-16 patients) where it was over 90% effective. OBJECTIVE: To estimate the effectiveness of the Bakri balloon for treating postpartum hemorrhage (PPH) in clinical practice at academic institutions. METHODS: This is a retrospective cohort study evaluating efficacy of Bakri balloon use in 35 women with PPH, performed as a chart review. Charts were reviewed to determine if balloon placement was deemed a "success" or "failure", as well as to abstract relevant demographic and clinical factors. Failure was defined as need for another form of hemorrhage control. RESULTS: Success rate was 67.57%. Bakri failure was associated with Cesarean section (67% versus 16%, p = 0.031) and predelivery Pitocin (67% versus 28%, p = 0.003) and had more ICU admissions (58% versus 4%, p = 0.0003), transfusions (5.4 red blood cell units versus 1.6, p = 0.007) and hospital days (5.65 versus 3.75, p = 0.011). Reasons for failure were continued bleeding or balloon extrusion. CONCLUSION: Our results suggest that the Bakri balloon is useful for treating PPH but not as effective as previously published. When balloon use is effective, however, the maternal morbidity is significantly decreased.

Pharmacology and placental transport of 17-hydroxyprogesterone caproate in singleton gestation.

OBJECTIVE: The purpose of this study was to estimate pharmacokinetic parameters and to evaluate placental transport of 17-hydroxyprogesterone caproate (17-OHPC) in singleton gestation. STUDY DESIGN: Sixty-one women who received weekly injections of 17-OHPC underwent 2 pharmacokinetic studies at 20 + 0 to 24 + 6 weeks' gestation (study 1) and 31 + 0 to 34 + 6 weeks' gestation (study 2); daily blood samples were obtained between injections. In 18 women, blood samples were obtained over a 28-day period beyond the last injection (extended study). Maternal and/or cord blood were obtained at delivery. RESULTS: The half-life (median ± SD) of 17-OHPC was 16.2 ± 6 days. Concentrations of 17-OHPC were higher during study 2 than during study 1. Body mass index affected maternal 17-OHPC concentrations. Cord:maternal 17-OHPC concentration ratios averaged 0.2; 17-OHPC was detectible in cord plasma 44 days after the last maternal injection. CONCLUSION: The apparent half-life of 17-OHPC is long, and pharmacokinetic parameters vary widely between subjects and are affected by maternal body mass index. The drug crosses the placental barrier.

Halting the revolving door of faculty turnover: recruiting and retaining clinician educators in an academic medical simulation center.

Simulation-based education is indispensable in preparing healthcare providers for patient care. Simulation centers and programs that serve as a critical platform for promoting patient safety and high-quality training depend on multiple requirements for success: diversified and sustainable financing, technical personnel with a long-term commitment to simulation education, simulation and information technology infrastructure designed to match priority training needs, and resources for curricular development, instruction, faculty development, and research. An additional requirement not widely discussed in the literature is the recruitment and retention of faculty who serve as simulation educators, which is the focus of this report.

Evaluation of force applied during deliveries complicated by shoulder dystocia using simulation.

OBJECTIVE: We sought to objectively evaluate the amount of force applied during deliveries complicated by shoulder dystocia among different providers. STUDY DESIGN: Providers who do deliveries at our institution were approached for participation. The simulation exercise used a childbirth mannequin that measures the amount of force the provider applies to the fetal head during delivery. The amount of force applied and information regarding the provider's level of experience, height, weight, and gender was recorded. This study was approved by the hospital institutional review board. RESULTS: A total of 47 providers participated. The mean force applied during each situation was not associated with the provider's experience, height, weight, or gender. CONCLUSION: Provider experience, gender, and body habitus were not associated with the amount of force applied during delivery. We found differences between family medicine and obstetrics/gynecology providers. In addition, a significant number of all providers (19/47, 40%) pulled >100 N.

In search of perinatal quality outcome measures: 1 hospital's in-depth analysis of the Adverse Outcomes Index.

OBJECTIVE: The purpose of this study was to assess the Adverse Outcome Index perinatal quality indicator system that was derived from administrative data. STUDY DESIGN: Adverse events were identified for 10 component measures; the Adverse Outcome Index was calculated by the National Perinatal Information Center from 42 months of administrative data. After retrospective chart review, we estimated positive predictive value for 10 measures that were obtained by corrected calculations of Adverse Outcome Index. RESULTS: Positive predictive values were 86-100% in 7 indicators, with lower values in 3 indicators: neonatal death, 0/2 fetuses; inborn birth trauma, 22/33 infants (67%); and maternal return to the operating room, 16/33 women (48.5%). In term admission to the neonatal intensive care unit, 107 false negatives were identified, with a negative predictive value of 45%. CONCLUSION: Indicator positive predictive value was variable. Performance can be strengthened by methods to identify both false-positive and false-negative adverse events that would include chart review and some measure specification revisions to improve alignment with original indicator intent. Interhospital comparison application requires further study.

Use of a postpartum hemorrhage simulator for instruction and evaluation of residents.

OBJECTIVE: Postpartum hemorrhage is a common and potentially life-threatening obstetric emergency. We sought to create a realistic simulation and validate a standardized grading form to evaluate competency in the management of postpartum hemorrhage. METHODS: Residents from 3 programs underwent training with a postpartum hemorrhage simulation using a standard obstetric birthing model equipped with an inflatable uterus to simulate uterine atony. All simulations were graded by staff physicians with a standardized grading sheet constructed from the current literature on the topic. Residents were expected to recognize the hemorrhage and take appropriate steps, including asking the assistant to administer medications, to correct the problem. Objective and subjective performance was measured with standardized grading sheets, and results were analyzed for reliability using Cronbach α and intraclass correlation coefficients. This project was conducted in accordance with the hospital Institutional Review Board policies at each institution. RESULTS: Forty residents from 3 institutions underwent simulation training. The majority were unable to correct the hemorrhage within 5 minutes and almost half also made at least 1 error, either the dose or route, in the medications they requested. Reliability was evaluated with Cronbach α and demonstrated the grading sheets were valid and had good interrater reliability. DISCUSSION: A simulated postpartum hemorrhage scenario can identify important deficiencies in resident knowledge and performance, with no risk to patients. The standardized grading form worked well for our purposes and was reliable in our study. Further testing is needed to evaluate whether the training improves performance in real-life hemorrhages.

Influence of obstetric practice on workload and practice patterns of family physicians and obstetrician-gynecologists.

PURPOSE: Obstetric practice among family physicians has declined in recent years. This study compared the practice patterns of family physicians and obstetrician-gynecologists with and without obstetric practices to provide objective information on one potential reason for this decline--the impact of obstetrics on physician lifestyle. METHODS: In 2004, we surveyed all obstetrician-gynecologists, all rural family physicians, and a random sample of urban family physicians identified from professional association lists (N =2,564) about demographics, practice characteristics, and obstetric practices. RESULTS: A total of 1,197 physicians (46.7%) overall responded to the survey (41.5% of urban family physicians, 54.7% of rural family physicians, and 55.0% of obstetrician-gynecologists). After exclusions, 991 were included in the final data set. Twenty-seven percent of urban family physicians, 46% of rural family physicians, and 79% of obstetrician-gynecologists practiced obstetrics. The mean number of total professional hours worked per week was greater with obstetric practice than without for rural family physicians (55.4 vs 50.2, P=.005) and for obstetrician-gynecologists (58.3 vs 43.5, P = .000), but not for urban family physicians (47.8 vs 49.5, P = .27). For all 3 groups, physicians practicing obstetrics were more likely to provide inpatient care and take call than physicians not practicing obstetrics. Large proportions of family physicians, but not obstetrician-gynecologists, took their own call for obstetrics. Concerns about the litigation environment and personal issues were the most frequent reasons for stopping obstetric practice. CONCLUSIONS: Practicing obstetrics is associated with an increased workload for family physicians. Organizing practices to decrease the impact on lifestyle may support family physicians in practicing obstetrics.

Professional liability issues and practice patterns of obstetric providers in Washington State.

OBJECTIVE: To describe recent changes in obstetric practice patterns and liability insurance premium costs and their consequences to Washington State obstetric providers (obstetrician-gynecologists, family physicians, certified nurse midwives, licensed midwives). METHODS: All obstetrician-gynecologists, rural family physicians, certified nurse midwives, licensed midwives, and a simple random sample of urban family physicians were surveyed about demographic and practice characteristics, liability insurance characteristics, practice changes and limitations due to liability insurance issues, obstetric practices, and obstetric practice environment changes. RESULTS: Fewer family physicians provide obstetric services than obstetrician-gynecologists, certified nurse midwives, and licensed midwives. Mean liability insurance premiums for obstetric providers increased by 61% for obstetrician-gynecologists, 75% for family physicians, 84% for certified nurse midwives, and 34% for licensed midwives from 2002 to 2004. Providers' most common monetary responses to liability insurance issues were to reduce compensation and to raise cash through loans and liquidating assets. In the 2 years of markedly increased premiums, obstetrician-gynecologists reported increasing their cesarean rates, their obstetric consultation rates, and the number of deliveries. They reported decreasing high-risk obstetric procedures during that same period. CONCLUSION: Liability insurance premiums rose dramatically from 2002 to 2004 for Washington's obstetric providers, leading many to make difficult financial decisions. Many obstetric providers reported a variety of practice changes during that interval. Although this study's results do not document an impending exodus of providers from obstetric practice, rural areas are most vulnerable because family physicians provide the majority of rural obstetric care and are less likely to practice obstetrics. LEVEL OF EVIDENCE: III.

Pharmacokinetics and pharmacodynamics of atenolol during pregnancy and postpartum.

Preexisting hypertension complicates 5% of all pregnancies. The objective of this study was to evaluate steady-state atenolol pharmacokinetics and pharmacodynamics (n = 17) during the second trimester (2nd T), third trimester (3rd T), and 3 months postpartum. Pregnancy as compared to 3 months postpartum (nonpregnant control) resulted in significant (P < .05) changes, including the following: 42% (2nd T) and 50% (3rd T) increase in creatinine clearance, 38% (2nd T) and 36% (3rd T) increase in atenolol renal clearance, 12% (2nd T) and 11% (3rd T) decrease in atenolol half-life, 20% (2nd T) and 28% (3rd T) increase in cardiac output, 15% (2nd T) and 23% (3rd T) increase in resting heart rate, and 22% (2nd T) and 21% (3rd T) decrease in total peripheral resistance in subjects on steady-state oral atenolol for treatment of hypertension in pregnancy. In conclusion, the renal clearance of atenolol along with creatinine clearance is increased during pregnancy. However, this does not translate into an increase in apparent oral clearance of atenolol, possibly related to the high variability in bioavailability. Atenolol administration did not appear to change the pattern of the increase in cardiac output and the decrease in total peripheral resistance, which normally occurs during pregnancy.

The effect of common clinical contaminants on amniotic fluid fluorescence polarization results.

OBJECTIVE: To determine the effect of blood, meconium, and vaginal secretions on amniotic fluid (AF) fluorescence polarization results. METHODS: Amniotic fluid was collected by transabdominal amniocentesis from women at 20-41 weeks of gestation and contaminated with blood, meconium, and vaginal secretions to concentrations of 0.5, 1, 2, 5, and 10%. An additional 20% concentration was performed with meconium and vaginal secretions. Fluorescence polarization was determined by a TDx Analyzer with the NBD-PC fluorescent probe. Results were compared for each contaminant by concentration level using repeated-measures analysis of variance. RESULTS: Forty-eight samples from women at a mean gestational age of 35 weeks (range 20-41.5 weeks) were evaluated. Before contamination, 16 (33%) samples had fluorescence polarization values greater than 290 mPol (immature), 10 (21%) were 260- 289 mPol (transitional), and 22 (46%) were less than 260 mPol (mature). Contamination with blood significantly altered fluorescence polarization values in AF samples with baseline values in the immature and mature categories such that values trended toward the transitional range. Contamination of baseline immature samples with vaginal secretions at 20% contamination level resulted in more mature fluorescence polarization values. Contamination with meconium more than 2% in the baseline immature category or more than 20% in the baseline transitional category also resulted in significantly more mature fluorescence polarization values. CONCLUSION: Amniotic fluid contamination with blood can result in more transitional range fluorescence polarization values, whereas contamination with meconium and vaginal secretions can result in more mature fluorescence polarization values.

The productivity of Washington State's obstetrician-gynecologist workforce: does gender make a difference?

OBJECTIVE: To compare the practice productivity of female and male obstetrician-gynecologists in Washington State. METHODS: The primary data collection tool was a practice survey that accompanied each licensed practitioner's license renewal in 1998-1999. Washington State birth certificate data were linked with the licensure data to obtain objective information regarding obstetric births. RESULTS: Of the 541 obstetrician-gynecologists identified, two thirds were men and one third were women. Women were significantly younger than men (mean age 43.3 years versus 51.7 years). Ten practice variables were evaluated: total weeks worked per year, total professional hours per week, direct patient care hours per week, nondirect patient care hours per week, outpatient visits per week, inpatient visits per week, percent practicing obstetrics, number of obstetrical deliveries per year, percentage working less than 32 hours per week, and percentage working 60 or more hours per week. Of these, only 2 variables showed significant differences: inpatient visits per week (women 10.1 per week, men 12.8 per week, P < or =.01) and working 60 or more hours per week (women 22.1% versus men 31.5%, P < or =.05). After controlling for age, analysis of covariance and multiple logistic regression confirmed these findings and in addition showed that women worked 4.1 fewer hours per week than men (P <.01). When examining the ratio of female-to-male practice productivity in 10-year age increments from the 30-39 through the 50-59 age groups, a pattern emerged suggesting lower productivity in many variables in the women in the 40-49 age group. CONCLUSION: Only small differences in practice productivity between men and women were demonstrated in a survey of nearly all obstetrician-gynecologists in Washington State. Changing demographics and behaviors of the obstetrician-gynecologist workforce will require ongoing longitudinal studies to confirm these findings and determine whether they are generalizable to the rest of the United States. LEVEL OF EVIDENCE: II-3

Fetal heart rate changes associated with uterine rupture.

OBJECTIVE: To identify fetal heart rate characteristics of patients with uterine rupture compared with successful vaginal birth after cesarean (VBAC) controls. METHODS: This is a case-control study. Obstetric records of patients at the University of Washington Medical Center and Swedish Medical Center were reviewed for cases of uterine rupture. Entry criteria included operative confirmation of the diagnosis, gestational age beyond 24 weeks, presence of one or more prior low transverse uterine incisions, and availability of fetal heart tracings. Each case was matched with 3 controls randomly selected from a pool of successful VBAC deliveries at the same institution within 1 year. Three blinded independent examiners then examined fetal heart tracings. Each tracing was rated for the presence of fetal tachycardia, mild or moderate variable decelerations, severe variable decelerations, late decelerations, prolonged decelerations, fetal bradycardia, and loss of uterine tone in both the first and second stages of labor separately. RESULTS: Of the 48 uterine ruptures identified, 36 met inclusion criteria. These were matched with 100 controls. Cases showed significantly increased rates of fetal bradycardia than controls in the first stage (P <.01) and second stage (P <.01). No significant differences were noted in rates of mild or severe variable decelerations, late decelerations, prolonged decelerations, fetal tachycardia, or loss of uterine tone. CONCLUSION: Fetal bradycardia in the first and second stage is the only finding to differentiate uterine ruptures from successful VBAC patients. LEVEL OF EVIDENCE: II-2