Society for Maternal-Fetal Medicine Special Statement: Checklist for initial management of amniotic fluid embolism.

Amniotic fluid embolism is a rare syndrome characterized by sudden cardiorespiratory collapse during labor or soon after delivery. Because of its rarity, many obstetrical providers have no experience in managing amniotic fluid embolism and may therefore benefit from a cognitive aid such as a checklist. We present a sample checklist for the initial management of amniotic fluid embolism based on standard management guidelines. We also suggest steps that each facility can take to implement the checklist effectively.

Amniotic fluid embolism syndrome: analysis of the Unites States International Registry.

BACKGROUND: Incidence, risk factors, and perinatal morbidity and mortality rates related to amniotic fluid embolism remain a challenge to evaluate, given the presence of differing international diagnostic criteria, the lack of a gold standard diagnostic test, and a significant overlap with other causes of obstetric morbidity and mortality. OBJECTIVE: The aims of this study were (1) to analyze the clinical features and outcomes of women using the largest United States-based contemporary international amniotic fluid embolism registry, and (2) to investigate differences in demographic and obstetric variables, clinical presentation, and outcomes between women with typical versus atypical amniotic fluid embolism, using previously published and validated criteria for the research reporting of amniotic fluid embolism. MATERIALS AND METHODS: The AFE Registry is an international database established at Baylor College of Medicine (Houston, TX) in partnership with the Amniotic Fluid Embolism Foundation (Vista, CA) and the Perinatology Research Branch of the Division of Intramural Research of the NICHD/NIH/DHHS (Detroit, MI). Charts submitted to the registry between August 2013 and September 2017 were reviewed, and cases were categorized into typical, atypical, non-amniotic fluid embolism, and indeterminate, using the previously published and validated criteria for the research reporting of AFE. Demographic and clinical variables, as well as outcomes for patients with typical and atypical AFE, were recorded and compared. Student t tests, χ2 tests, and analysis of variance tables were used to compare the groups, as appropriate, using SAS/STAT software, version 9.4. RESULTS: A total of 129 charts were available for review. Of these, 46% (59/129) represented typical amniotic fluid embolism and 12% (15/129) atypical amniotic fluid embolism, 21% (27/129) were non-amniotic fluid embolism cases with a clear alternative diagnosis, and 22% (28/129) had an uncertain diagnosis. Of the 27 women misclassified as an amniotic fluid embolism with an alternative diagnosis, the most common actual diagnosis was hypovolemic shock secondary to postpartum hemorrhage. Ten percent (6/59) of the women with typical amniotic fluid embolism had a pregnancy complicated by placenta previa, and 8% (5/61) had undergone in vitro fertilization to achieve pregnancy. In all, 66% (49/74) of the women with amniotic fluid embolism reported a history of atopy or latex, medication, or food allergy, compared to 34% of the obstetric population delivered at our hospital over the study period (P < .05). CONCLUSION: Our data represent a series of women with amniotic fluid embolism whose diagnosis has been validated by detailed chart review, using recently published and validated criteria for research reporting of amniotic fluid embolism. Although no definitive risk factors were identified, a high rate of placenta previa, reported allergy, and conceptions achieved through in vitro fertilization was observed.

Shock index and delta-shock index are superior to existing maternal early warning criteria to identify postpartum hemorrhage and need for intervention.

OBJECTIVE: To determine whether shock index (SI) is superior to traditional vital signs in predicting postpartum hemorrhage and need for intervention. METHODS: Retrospective case-control study in an academic tertiary-care county hospital. Forty-one consecutive postpartum hemorrhage (PPH) cases and 41 controls were frequency-matched by mode of delivery and maternal weight. We measured four criteria: heart rate, systolic blood pressure (SBP), SI (HR/SBP), and delta-SI (peak SI - baseline SI). Using received operating characteristic curves, we compared the discrimination performance of each criterion to predict PPH, transfusion, and surgical intervention, and identified thresholds with the strongest classification. RESULTS: SI ≤1.1 can be normal in peripartum. Peak SI and delta-SI were generally superior to heart rate (HR) and SBP in predicting PPH, transfusion, and surgical intervention. SI ≥1.143 and SI ≥1.412 were strong initial and "critical" thresholds. Delta-SI was the strongest classifier overall; both SI and delta-SI remain sensitive and specific when adjusted for potential confounders. CONCLUSIONS: SI and delta-SI appear to be superior to HR and SBP in predicting PPH and need for intervention. Utility of delta-SI should be prospectively explored.

Maternal and Fetal Death on Weekends.

BACKGROUND: Higher mortality rates have been reported in patients admitted to the hospital on weekends. This study aimed to compare maternal mortality ratio (MMR), fetal mortality ratio, and other maternal and neonatal outcomes by day of death or delivery in the United States. METHODS: Our database consisted of a population-level analysis of live births and maternal and fetal deaths between 2004 and 2014 in the United States from the Centers for Disease Control and Prevention's National Center for Health Statistics. We also examined the relationship between these deaths and various documented maternal and fetal clinical conditions. RESULTS: A total of 2,061 maternal deaths occurred on weekends and 5,510 deaths on weekdays. During the same period of time, 65,063 and 210,851 cases of fetal demise were delivered on weekends and on weekdays, respectively. Maternal mortality was significantly higher on weekends than weekdays (22.9 vs. 15.3/100,000 live births, p < 0.001) as was fetal mortality (7.21 vs. 5.85/100,000, p < 0.001), despite a lower frequency of serious comorbidities among women delivering on weekends. CONCLUSION: Our data demonstrate a significant increase in the U.S. MMR and stillbirth delivery on weekends. Relative representation of antepartum, intrapartum, and postpartum deaths cannot be ascertained from these data.

Reducing Maternal Mortality and Severe Maternal Morbidity: The Role of Critical Care.

Throughout most of the 20th century, the risk of maternal mortality in high resource countries decreased dramatically; however, this trend recently has stalled in the United States and appears to have reversed. Equally alarming is that for every reported maternal death, there are numerous severe maternal morbidities or near misses. Shifting maternal demographics (eg, obesity, advanced maternal age, multifetal pregnancies), with attendant significant medical comorbidities (eg, hypertension, diabetes, cardiac disease) and the increase in cesarean deliveries significantly contribute to increased maternal morbidity and mortality. This chapter focuses on the role of critical care in reducing maternal mortality and morbidity.

Health Care Disparity and Pregnancy-Related Mortality in the United States, 2005-2014.

OBJECTIVE: To quantitate the contribution of various demographic factors to the U.S. maternal mortality ratio. METHODS: This was a retrospective observational study. We analyzed data from the Centers for Disease Control and Prevention (CDC) National Center for Health Statistics database and the Detailed Mortality Underlying Cause of Death database (CDC WONDER) from 2005 to 2014 that contains mortality and population counts for all U.S. counties. Bivariate correlations between the maternal mortality ratio and all maternal demographic, lifestyle, health, and medical service utilization characteristics were calculated. We performed a maximum likelihood factor analysis with varimax rotation retaining variables that were significant (P<.05) in the univariate analysis to deal with multicollinearity among the existing variables. RESULTS: The United States has experienced an increase in maternal mortality ratio since 2005 with rates increasing from 15 per 100,00 live births in 2005 to 21-22 per 100,000 live births in 2013 and 2014. (P<.001) This increase in mortality was most pronounced in non-Hispanic black women, with ratios rising from 39 to 49 per 100,000 live births. A significant correlation between state mortality ranking and the percentage of non-Hispanic black women in the delivery population was demonstrated. Cesarean deliveries, unintended births, unmarried status, percentage of deliveries to non-Hispanic black women, and four or fewer prenatal visits were significantly (P<.05) associated with the increased maternal mortality ratio. CONCLUSION: The current U.S. maternal mortality ratio is heavily influenced by a higher rate of death among non-Hispanic black or unmarried patients with unplanned pregnancies. Racial disparities in health care availability and access or utilization by underserved populations are important issues faced by states seeking to decrease maternal mortality.

Outcomes of Planned Compared With Urgent Deliveries Using a Multidisciplinary Team Approach for Morbidly Adherent Placenta.

OBJECTIVE: To compare outcomes between planned and urgent cesarean hysterectomy for morbidly adherent placenta managed by a multidisciplinary team. METHODS: This is a retrospective case-control study of women with singleton pregnancies with antenatally suspected and pathologically confirmed morbidly adherent placenta who underwent cesarean hysterectomy between January 1, 2011, and February 30, 2017. Timing of delivery was classified as either planned (delivery at 34-35 weeks of gestation) or urgent (need for urgent delivery as a result of uterine contractions, bleeding, or both). The primary outcome variable was composite maternal morbidity. Logistic regression analysis was used to evaluate risk factors for urgent delivery. RESULTS: One hundred thirty patients underwent hysterectomy. Sixty (46.2%) required urgent delivery. Composite maternal morbidity was identified in 34 (56.7%) of the urgent and 26 (37.1%) of the planned deliveries (P=.03). Fewer units of red blood cells and fresh frozen plasma were transfused in the planned delivery group (red blood cells, median interquartile range 3 [0-8] versus 1 [0-4], P=.02; fresh frozen plasma, median interquartile range 1 [0-2] versus 0 [0-0], P=.001). Rates of low Apgar score and respiratory distress syndrome were higher in the urgent compared with the planned delivery group (5-minute Apgar score less than 7, 34 [59.6%] versus 14 [23.3%], P<.01; respiratory distress syndrome, 34 [61.8%] versus 16 [27.1%], P<.01). A history of two or more prior cesarean deliveries was an independent predictor of urgent delivery (adjusted odds ratio 11.4, 95% CI 1.8-71.1). CONCLUSION: Women with morbidly adherent placenta requiring urgent delivery have a worse outcome than women with planned delivery. Women with morbidly adherent placenta and two or more prior cesarean deliveries are at increased risk for urgent delivery. In such women, scheduling delivery before the standard 34- to 35-week timeframe may be reasonable.

Cyanotic congenital heart disease following fertility treatments in the United States from 2011 to 2014.

OBJECTIVE: To examine the risk for cyanotic congenital heart diseases (CCHDs) among live births in the USA, resulting from various forms of infertility treatments. METHODS: This study is a cross-sectional analysis of live births in the USA from 2011 to 2014. Infertility treatments are categorised into two of the following groups on birth certificates: assisted reproductive technology (ART) fertility treatment (surgical egg removal; eg, in vitro fertilisation and gamete intrafallopian transfer) and non-ART fertility treatment (eg, medical treatment and intrauterine insemination). We compared the risk for CCHD in ART and non-ART fertility treatment groups with those infants whose mothers received no documented fertility treatment and were naturally conceived (NC). RESULTS: Among 14 242 267 live births from 2011 to 2014, a total of 101 494 live births were in the ART and 81 242 resulted from non-ART fertility treatments. CCHD prevalence in ART, non-ART and NC groups were 393/100 892 (0.39%), 210/80 884 (0.26%) and 10 749/14 020 749 (0.08%), respectively. As compared with naturally conceiving infants, risk for CCHD was significantly higher among infants born in ART (adjusted relative risk (aRR) 2.4, 95% CI 2.1 to 2.7) and non-ART fertility treatment groups (aRR 1.9, 95% CI 1.6 to 2.2). Absolute risk increase in CCHD due to ART and non-ART treatments were 0.03% and 0.02%, respectively. A similar pattern was observed when the analysis was restricted to twins, newborns with birth weights under 1500 g and gestational age of less than 32 weeks. CONCLUSIONS: Our findings suggest an increased risk for CCHD in infants conceived after all types of infertility treatment.

Effect of advanced maternal age on maternal and neonatal outcomes in assisted reproductive technology pregnancies.

OBJECTIVES: To compare maternal and neonatal outcomes between women with assisted reproductive technologies pregnancy aged <40, 40-44, 45-49, and ≥50 years. STUDY: Design In a population-level analysis study, all live births by ART identified on birth certificate between 2011 and 2014 were extracted (n=101,494) using data from the Center for Disease Control and Prevention-National Center for Health Statistics (CDC-NCHS). We investigated and compared maternal and neonatal outcomes based on conditions routinely listed on birth certificates. RESULTS: Of 101,494 ART live births, 79,786 (78.6%), 16,186 (15.9%), 4637 (4.6%), and 885 (0.9%) were delivered by women aged <40, 40-44, 45-49, and ≥50 years, respectively. Comparing to women aged <40years, women aged 40-44, 45-49, and ≥50 years were at increased risk for gestational hypertension (aRR: 1.26, 1.55, and 1.61, respectively), gestational diabetes (aRR: 1.23, 1.40, and 1.31, respectively), eclampsia (aRR: 1.49, 1.51, and 2.37, respectively), unplanned hysterectomy (aRR: 2.55, 4.05, and 3.02, respectively), and ICU admission (aRR: 1.64, 2.06, and 2.04, respectively). The prevalence of preterm delivery was slightly higher in women aged 45 and older. (35%, 36.9%, and 40.2% in women aged <40 years, 45-49 years, and ≥50 years, respectively) CONCLUSIONS: Advanced age ART was significantly associated with higher rates of maternal morbidities. Except for preterm delivery, neonatal outcomes were similar between ART pregnancies in women aged ≥45 years and younger women. These data should be interpreted with caution because of potential confounding by potentially higher use of donor eggs by older women, the exact rates for which we were unable to ascertain from the available data.

A survey of honor-related practices among US obstetricians and gynecologists.

OBJECTIVE: To assess patterns of honor-related practices-including virginity testing, virginity restoration, and female genital mutilation (FGM)-among US obstetrician-gynecologists (OBGYNs). METHODS: Between June 1 and August 31, 2016, 1000 members of the American College of Obstetricians and Gynecologists were invited by email to complete an anonymous online survey. The survey comprised 42 questions evaluating the demographic and practice characteristics of the respondents. RESULTS: Overall, 288 of the 909 practicing US OBGYNs with functioning email addresses completed the survey (31.7% response rate). In the 12 months before the survey, 168 (58.3%) respondents had provided care to one or more patients who had previously undergone FGM. Care was also provided for patients who requested virginity testing or virginity restoration by 29 (10.1%) and 16 (5.6%) respondents, respectively. Ten (3.5%) respondents performed virginity testing on request, whereas 3 (1.0%) performed virginity restoration. CONCLUSION: Some respondents performed honor-related practices, which indicated a need to educate all practicing US OBGYNs about their ethical and legal obligations in the care of such patients.

An Initiative to Reduce the Episiotomy Rate: Association of Feedback and the Hawthorne Effect With Leapfrog Goals.

OBJECTIVE: To assess the association of education, performance feedback, and the Hawthorne effect with a reduction in the episiotomy rate in a large academic institution. METHODS: We describe a prospective observational study of a project conducted between March 2012 and February 2017 to assist clinicians in meeting the Leapfrog Group (www.leapfroggroup.org) target rates for episiotomy. Phases of this project included preintervention (phase 1, March 2012 to April 2014), education and provision of collective department episiotomy rates (phase 2, May 2014 to December 2014), ongoing education with emphasis on a revised Leapfrog target rate (phase 3, January 2015 to February 2016), and provision of individual episiotomy rates to practitioners on a monthly basis (phase 4, March 2016 to February 2017). We analyzed the department episiotomy rates before, during, and after these efforts. Cases of shoulder dystocia were excluded from this analysis. Statistical analysis was performed using a two-tailed Student t test and χ test with P<.05 considered significant. RESULTS: During the study period 1,176 episiotomies were performed in 16,441 vaginal deliveries (7.2%). In phase 2 (2,352 vaginal deliveries), there was a nonsignificant drop in the episiotomy rate with education alone (9.0-8.2%, P=.21). In phase 3 (4,379 vaginal deliveries), the episiotomy rate demonstrated an additional, significant drop to 5.9% (P<.001), but this reduction did not reach the new Leapfrog goal of 5%. In phase 4 (3,160 vaginal deliveries), the hospital episiotomy rate again dropped significantly from 5.9% to 4.37% (P=.007) and met the target rate of 5%. This reduction was sustained over a 12-month time period. During this same time period, the rate of operative vaginal delivery among vaginal births increased (4.5-5.4%, P=.003) and there was no significant change in the rates of third- and fourth-degree perineal laceration (3.8-3.3%, P=.19). CONCLUSION: Education, performance feedback, and the Hawthorne effect were associated with a reduction in the episiotomy rate in a large academic institution without a reduction in the rate of operative vaginal delivery or an increase in the rate of third- and fourth-degree lacerations.

Under Pressure: Intraluminal Filling Pressures of Postpartum Hemorrhage Tamponade Balloons.

Objective Uterine tamponade by fluid-filled balloons is now an accepted method of controlling postpartum hemorrhage. Available tamponade balloons vary in design and material, which affects the filling attributes and volume at which they rupture. We aimed to characterize the filling capacity and pressure-volume relationship of various tamponade balloons. Study Design Balloons were filled with water ex vivo. Intraluminal pressure was measured incrementally (every 10 mL for the Foley balloons and every 50 mL for all other balloons). Balloons were filled until they ruptured or until 5,000 mL was reached. Results The Foley balloons had higher intraluminal pressures than the larger-volume balloons. The intraluminal pressure of the Sengstaken-Blakemore tube (gastric balloon) was initially high, but it decreased until shortly before rupture occurred. The Bakri intraluminal pressure steadily increased until rupture occurred at 2,850 mL. The condom catheter, BT-Cath, and ebb all had low intraluminal pressures. Both the BT-Cath and the ebb remained unruptured at 5,000 mL. Conclusion In the setting of acute hemorrhage, expeditious management is critical. Balloons that have a low intraluminal pressure-volume ratio may fill more rapidly, more easily, and to greater volumes. We found that the BT-Cath, the ebb, and the condom catheter all had low intraluminal pressures throughout filling.

Reproductive decisions after the diagnosis of amniotic fluid embolism.

OBJECTIVE: This study aims to describe the subsequent reproductive outcomes in women who either correctly or incorrectly were diagnosed with amniotic fluid embolism (AFE). STUDY DESIGN: Medical records were obtained, abstracted and reviewed by authors with extensive experience in critical care obstetrics. Telephone interviews of all survivors were conducted to determine obstetrical and contraceptive history. A subgroup underwent further telephone interview to address subsequent reproductive decisions. RESULTS: By November 2015, 116 medical records of patients diagnosed with AFE were reviewed. Patients who had undergone hysterectomy (n=26), died (n=9), or developed Sheehan's syndrome (n=1) at the time of the original event were excluded from the present analysis. Of the remaining 80 women, 30% (24/80) had subsequently conceived and 32.5% (26/80) patients or their partners had undergone permanent sterilization. At the time of this report, 66% (21/32) of registry participants were categorized to have had AFE and 34% (11/32) as not likely AFE or indeterminate. CONCLUSIONS: The syndrome of AFE is over-diagnosed. Women diagnosed with AFE who survive conceive another pregnancy less frequently than US women over similar time intervals and often choose a permanent sterilization method, whether or not they actually had AFE, largely out of fear of AFE recurrence.

Multidisciplinary team learning in the management of the morbidly adherent placenta: outcome improvements over time.

BACKGROUND: Morbidly adherent placenta (MAP) is a serious obstetric complication causing mortality and morbidity. OBJECTIVE: To evaluate whether outcomes of patients with MAP improve with increasing experience within a well-established multidisciplinary team at a single referral center. STUDY DESIGN: All singleton pregnancies with pathology-confirmed MAP (including placenta accreta, increta, or percreta) managed by a multidisciplinary team between January 2011 and August 2016 were included in this retrospective study. Turnover of team members was minimal, and cases were divided into 2 time periods so as to compare 2 similarly sized groups: T1 = January 2011 to April 2014 and T2 = May 2014 to August 2016. Outcome variables were estimated blood loss, units of red blood cell transfused, volume of crystalloid transfused, massive transfusion protocol activation, ureter and bowel injury, and neonatal birth weight. Comparisons and adjustments were made by use of the Student t test, Mann-Whitney U test, χ2 test, analysis of covariance, and multinomial logistic regression. RESULTS: A total of 118 singleton pregnancies, 59 in T1 and 59 in T2, were managed during the study period. Baseline patient characteristics were not statistically significant. Forty-eight of 59 (81.4%) patients in T1 and 42 of 59 (71.2%) patients in T2 were diagnosed with placenta increta/percreta. The median [interquartile range] estimated blood loss (T1: 2000 [1475-3000] vs T2: 1500 [1000-2700], P = .04), median red blood cell transfusion units (T1: 2.5 [0-7] vs T2: 1 [0-4], P = .02), and median crystalloid transfusion volume (T1: 4200 [3600-5000] vs T2: 3400 [3000-4000], P < .01) were significantly less in T2. Also, a massive transfusion protocol was instituted more frequently in T1: 15/59 (25.4%) vs 3/59 (5.1%); P < .01. Neonatal outcomes and surgical complications were similar between the 2 groups. CONCLUSION: Our study shows that patient outcomes are improved over time with increasing experience within a well-established multidisciplinary team performing 2-3 cases per month. This suggests that small, collective changes in team dynamics lead to continuous improvement of clinical outcomes. These findings support the development of centers of excellence for MAP staffed by stable, core multidisciplinary teams, which should perform a significant number of these procedures on an ongoing basis.

Trends in the delivery route of twin pregnancies in the United States, 2006-2013.

OBJECTIVES: To determine the trends of cesarean delivery rate among twin pregnancies from 2006 to 2013. STUDY DESIGN: This is a population-based, cross-sectional analysis of twin live births from United State birth data files of the National Center for Health Statistics for calendar years 2006 through 2013. We stratified the population based on the gestational age groups, maternal race/ethnicity, advanced maternal age (AMA) which was defined by age more than 35 years and within the standard birth weight groups (group 1: birth weight 500-1499g, group 2: birth weight 1500-2499g and group 3: birth weight >2500g). We also analyzed the effect of different risk factors for cesarean delivery in twins. RESULTS: There were 1,079,102 infants born of twin gestations in the U.S. from 2006 to 2013, representing a small but significant increase in the proportion of twin births among all births (3.2% in 2006 versus 3.4% in 2013). The rate of cesarean delivery in twin live births peaked at 75.3% in 2009, and was significantly lower (74.8%) in 2013. The rate of the twin live birth with the breech presentation increased steadily from 26.3% in 2006 to 29.1% in 2013. For the fetus of the twin pregnancy presented as breech, the cesarean delivery rate peaked at 92.2% in 2010, falling slightly but significantly in the ensuing 3 years. The results demonstrated that the decrease in cesarean delivery rate was due to fewer cesareans in non-Hispanic white patients; all other ethnic subgroups showed increasing rates of cesarean delivery throughout the study. Gestational diabetes, gestational hypertension, previous cesarean delivery and breech presentation were all significant risk factors for cesarean delivery during the entire study period. Induction of labor and premature rupture of the membranes were associated with lower rates of cesarean delivery in twins. CONCLUSION: The recent decrease in the cesarean delivery rate in twin gestation appears to be largely attributable to a decline in cesarean among pregnancies complicated by breech presentation in non-Hispanic white women, and may reflect a health care disparity that deserves further research.

Health Care Disparity and State-Specific Pregnancy-Related Mortality in the United States, 2005-2014.

OBJECTIVE: To investigate factors associated with differential state maternal mortality ratios and to quantitate the contribution of various demographic factors to such variation. METHODS: In a population-level analysis study, we analyzed data from the Centers for Disease Control and Prevention National Center for Health Statistics database and the Detailed Mortality Underlying Cause of Death database (CDC WONDER) that contains mortality and population counts for all U.S. counties. Bivariate correlations between maternal mortality ratio and all maternal demographic, lifestyle, health, and medical service utilization characteristics were calculated. We performed a maximum likelihood factor analysis with varimax rotation retaining variables that were significant (P<.05) in the univariate analysis to deal with multicollinearity among the existing variables. RESULTS: The United States has experienced a continued increase in maternal mortality ratio since 2007 with rates of 21-22 per 100,000 live births in 2013 and 2014. This increase in mortality was most dramatic in non-Hispanic black women. There was a significant correlation between state mortality ranking and the percentage of non-Hispanic black women in the delivery population. Cesarean deliveries, unintended births, unmarried status, percentage of non-Hispanic black deliveries, and four or less prenatal visits were significantly (P<.05) associated with increased maternal mortality ratio. CONCLUSION: Interstate differences in maternal mortality ratios largely reflect a different proportion of non-Hispanic black or unmarried patients with unplanned pregnancies. Racial disparities in health care availability, access, or utilization by underserved populations are an important issue faced by states in seeking to decrease maternal mortality.

Obstetric Forceps: A Species on the Brink of Extinction.

Both resident training in the use of obstetric forceps and forceps deliveries are experiencing precipitous declines in the United States. Current minimum training requirements are insufficient to ensure competency in this skill. These trends bear striking similarities to observations regarding the decline and ultimate extinction of biologic species and portend the inevitable disappearance of this valuable skill from the obstetric armamentarium. Attempts by experienced teaching faculty to provide residents with experience in a few forceps deliveries are of little value and may do more harm than good. There would seem to be only two viable solutions to this dilemma: 1) abandon attempts to teach forceps and prepare residents for a real-world practice setting in which management of second-stage labor does not include the availability forceps delivery; or 2) prioritize the development of high-fidelity simulation models in which fetal head size and attitude and pelvic size and architecture can be continuously varied to allow residents to obtain sufficient experience to know both how and when to proceed with forceps delivery. We believe this latter approach is the sole alternative to inevitable extinction of this species.

Birth Rates Among Hispanics and Non-Hispanics and their Representation in Contemporary Obstetric Clinical Trials.

Objective Our study aims were to establish whether subjects enrolled in current obstetric clinical trials proportionately reflects the contemporary representation of Hispanic ethnicities and their birth rates in the United States. Methods Using comprehensive source data over a defined interval (January 2011-September 2015) on birth rates by ethnicity from the Centers for Disease Control and Prevention (CDC), we evaluated the proportional rate by ethnicity, then analyzed the observed to expected relative ratio of enrolled subjects. Results Hispanic women comprise a significant contribution to births in the United States (23% of all births). Systematic analysis of 90 published obstetric clinical trials showed a correlation between inclusion of Hispanic gravidae and the corresponding state's birth rates (r = 0.501, p < 0.001). While the mean was strongly correlated, individual clinical trials may have relatively over-enrolled (n = 31, or 34%) or under-enrolled (n = 33, or 37%) relative to their regional population. In 48% of obstetric clinical trials the Hispanic proportion of the study population was not reported. Conclusion Hispanic gravidae represent a significant number of contemporary U.S. births, and are generally adequately represented as obstetric subjects in clinical trials. However, this is trial-dependent, with significant trial-specific under- and over-enrollment of Hispanic subjects relative to the regional birth population.