Race, ethnicity, and indications for primary cesarean birth: Associations within a national birth center registry

BACKGROUND

Racial and ethnic disparities in cesarean rates in the United States are well documented. This study investigated whether cesarean inequities persist in midwife-led birth center care, including for individuals with the lowest medical risk.

METHODS

National registry records of 174,230 childbearing people enrolled in care in 115 midwifery-led birth center practices between 2007 and 2022 were analyzed for primary cesarean rates and indications by race and ethnicity. The lowest medical risk subsample (n = 70,521) was analyzed for independent drivers of cesarean birth.

RESULTS

Primary cesarean rates among nulliparas (15.5%) and multiparas (5.7%) were low for all enrollees. Among nulliparas in the lowest-risk subsample, non-Latinx Black (aOR = 1.37; 95% CI, 1.15-1.63), Latinx (aOR = 1.51; 95% CI, 1.32-1.73), and Asian participants (aOR = 1.48; 95% CI, 1.19-1.85) remained at higher risk for primary cesarean than White participants. Among multiparas, only Black participants experienced a higher primary cesarean risk (aOR = 1.49; 95% CI, 1.02-2.18). Intrapartum transfers from birth centers were equivalent or lower for Black (14.0%, p = 0.345) and Latinx (12.7%, p < 0.001) enrollees. Black participants experienced a higher proportion of primary cesareans attributed to non-reassuring fetal status, regardless of risk factors. Place of admission was a stronger predictor of primary cesarean than race or ethnicity.

CONCLUSIONS

Place of first admission in labor was the strongest predictor of cesarean. Racism as a chronic stressor and a determinant of clinical decision-making reduces choice in birth settings and may increase cesarean rates. Research on components of birth settings that drive inequitable outcomes is warranted.

An alternative model of maternity care for low-risk birth: Maternal and neonatal outcomes utilizing the midwifery-based birth center model

OBJECTIVE

To assess key birth outcomes in an alternative maternity care model, midwifery-based birth center care.

DATA SOURCES

The American Association of Birth Centers Perinatal Data Registry and birth certificate files, using national data collected from 2009 to 2019.

STUDY DESIGN

This observational cohort study compared key clinical birth outcomes of women at low risk for perinatal complications, comparing those who received care in the midwifery-based birth center model versus hospital-based usual care. Linear regression analysis was used to assess key clinical outcomes in the midwifery-based group as compared with hospital-based usual care. The hospital-based group was selected using nearest neighbor matching, and the primary linear regressions were weighted using propensity score weights (PSWs). The key clinical outcomes considered were cesarean delivery, low birth weight, neonatal intensive care unit admission, breastfeeding, and neonatal death. We performed sensitivity analyses using inverse probability weights and entropy balancing weights. We also assessed the remaining role of omitted variable bias using a bounding methodology.

DATA COLLECTION

Women aged 16-45 with low-risk pregnancies, defined as a singleton fetus and no record of hypertension or cesarean section, were included. The sample was selected for records that overlapped in each year and state. Counties were included if there were at least 50 midwifery-based birth center births and 300 total births. After matching, the sample size of the birth center cohort was 85,842 and the hospital-based cohort was 261,439.

PRINCIPAL FINDINGS

Women receiving midwifery-based birth center care experienced lower rates of cesarean section (-12.2 percentage points, p < 0.001), low birth weight (-3.2 percentage points, p < 0.001), NICU admission (-5.5 percentage points, p < 0.001), neonatal death (-0.1 percentage points, p < 0.001), and higher rates of breastfeeding (9.3 percentage points, p < 0.001).

CONCLUSIONS

This analysis supports midwifery-based birth center care as a high-quality model that delivers optimal outcomes for low-risk maternal/newborn dyads.

The birth center model of care: Staffing, business characteristics, and core clinical outcomes

OBJECTIVES

Interest in expanding access to the birth center model is growing. The purpose of this research is to describe birth center staffing models and business characteristics and explore relationships to perinatal outcomes.

METHODS

This descriptive analysis includes a convenience sample of all 84 birth center sites that participated in the AABC Site Survey and AABC Perinatal Data Registry between 2012 and 2020. Selected independent variables include staffing model (CNM/CM or CPM/LM), legal entity status, birth volume/year, and hours of midwifery call/week. Perinatal outcomes include rates of induction of labor, cesarean birth, exclusive breastfeeding, birthweight in pounds, low APGAR scores, and neonatal intensive care admission.

RESULTS

The birth center model of care is demonstrated to be safe and effective, across a variety of staffing and business models. Outcomes for both CNM/CM and CPM/LM models of care exceed national benchmarks for perinatal quality with low induction, cesarean, NICU admission, and high rates of breastfeeding. Within the sample of medically low-risk multiparas, variations in clinical outcomes were correlated with business characteristics of the birth center, specifically annual birth volume. Increased induction of labor and cesarean birth, with decreased success breastfeeding, were present within practices characterized as high volume (>200 births/year). The research demonstrates decreased access to the birth center model of care for Black and Hispanic populations.

CONCLUSIONS FOR PRACTICE

Between 2012 and 2020, 84 birth centers across the United States engaged in 90,580 episodes of perinatal care. Continued policy development is necessary to provide risk-appropriate care for populations of healthy, medically low-risk consumers.

Strong Start Innovation: Equitable Outcomes Across Public and Privately Insured Clients Receiving Birth Center Care

INTRODUCTION

The Birth Center model of care is a health care delivery innovation in its fourth decade of demonstration across the United States. The purpose of this research was to evaluate the model's potential for decreasing poverty-related health disparities among childbearing families.

METHODS

Between 2013 and 2017, 26,259 childbearing people received care within the 45 Center for Medicare and Medicaid Innovation Strong Start birth center sites. Secondary analysis of the prospective American Association of Birth Centers Perinatal Data Registry was conducted. Descriptive statistics described sociobehavioral, medical risk factors, and core clinical outcomes to inform the logistic regression model. Privately insured consumers were independently compared with 2 subgroups of Medicaid beneficiaries: Strong Start enrollees (midwifery-led care with peer counselors) and non-Strong Start Medicaid beneficiaries (midwifery-led care without peer counselors).

RESULTS

After controlling for medical risk factors, Strong Start Medicaid beneficiaries achieved similar outcomes to privately insured consumers with no significant differences in maternal or newborn outcomes between groups. Perinatal outcomes included induction of labor (adjusted odds ratio [aOR], 0.86; 95% CI 0.61-1.13), epidural analgesia use (aOR, 1.00; 95% CI, 0.68-1.48), cesarean birth (aOR, 1.16; 95% CI, 0.87-1.53), exclusive breastfeeding on discharge (aOR, 1.11; 95% CI, 0.48-2.56), low Apgar score at 5 minutes (aOR, 1.23; 95% CI, 0.86-1.83), low birth weight (aOR, 1.12; 95% CI, 0.77-1.64), and antepartum transfer of care after the first prenatal appointment (aOR, 1.53; 95% CI, 0.97-2.40). Medicaid beneficiaries who were not enrolled in the Strong Start midwifery-led, peer counselor program demonstrated similar results except for having higher epidural analgesia use (aOR, 1.30; 95% CI, 1.10-1.53) and significantly lower exclusive breastfeeding on discharge (aOR, 0.57; 95% CI, 0.40-0.81) than their privately insured counterparts.

DISCUSSION

The midwifery-led birth center model of care complemented by peer counselors demonstrated a pathway to achieve health equity.

The psychosocial and emotional experiences of cancer patients during the COVID-19 pandemic: A systematic review

BACKGROUND

COVID-19 was declared a pandemic by the World Health Organization on March 11th, 2020. Global social lockdowns were instigated to reduce spread and prevent health-services from becoming overwhelmed. People having treatment for cancer are known to have heightened psychological/emotional burden. The combined impact of managing pandemic regulations alongside this may present additional burden. The purpose of this systematic review is to examine current evidence of the psychological and emotional impact of COVID-19 on people with cancer, early in the pandemic.

METHODS

Five electronic databases were searched (Embase, Global Health, HMIC, PsychINFO, CINAHL) from September 2019 to October 2021. Qualitative, quantitative and mixed-method primary research studies exploring emotional and psychological impacts of COVID-19 on cancer patients, limited to English language, were included. Quality appraisal was conducted using the MMAT.

RESULTS

Fifty-one papers, with 27,356 people from 21 countries treated for cancer, were included. 43 studies were quantitative with a survey method approach, six studies qualitative and four used a mixed methods design. MMAT score was mostly two or three. Four themes were identified: Emotional aspects and Quality of Life; Psychosocial aspects; Impact of COVID-19 on self; Impact of COVID-19 on cancer, with themes overlapping.

CONCLUSION

Whilst emotional/psychological impacts such as anxiety, isolation, employment fears, and uncertainty about the future were potentially universal concerns early in the pandemic, they may have been particularly acute for people living with cancer and represent complex, overlapping factors. As COVID-19 continues to impact health-services and society, it is important to focus on any ongoing impact to the experience of cancer patients. Most of the studies reviewed used tools that do not provide deeper understanding of how and why emotional states of people with cancer were affected. Further qualitative work may reveal patterns of what was unique to cancer patients during the pandemic, compared to general populations.

Progesterone and Preterm Birth: Using Empirical Research to Explore Structural Racism Within Midwifery-Led Care

BACKGROUND

Progesterone has been the standard of practice for the prevention of preterm birth for decades. The drug received expedited Food and Drug Administration approval, prior to the robust demonstration of scientific efficacy.

METHODS

Prospective research from the American Association of Birth Centers Perinatal Data Registry, 2007-2020. Two-tailed t tests, logistic regression, and propensity score matching were used.

RESULTS

Midwifery-led care was underutilized by groups most at risk for preterm birth and was shown to be effective at maintaining low preterm birth rates. The model did not demonstrate reliable access to progesterone. People of color are most at risk of preterm birth, yet were least likely to receiving progesterone treatment. Progesterone was not demonstrated to be effective at decreasing preterm birth when comparing the childbearing people with a history of preterm birth who used the medication and those who did not within this sample.

CONCLUSIONS

This study adds to the body of research that demonstrates midwifery-led care and low preterm birth rates. The ineffectiveness of progesterone in the prevention of preterm birth among people at risk was demonstrated.

Place of Birth Preferences and Relationship to Maternal and Newborn Outcomes Within the American Association of Birth Centers Perinatal Data Registry, 2007-2020

PURPOSE

The purpose of this study was to describe sociodemographic variations in client preference for birthplace and relationships to perinatal health outcomes.

METHODS

Descriptive data analysis (raw number, percentages, and means) showed that preference for birthplace varied across racial and ethnic categories as well as sociodemographic categories including educational status, body mass index, payer status, marital status, and gravidity. A subsample of medically low-risk childbearing people, qualified for birth center admission in labor, was analyzed to assess variations in maternal and newborn outcomes by site of first admission in labor.

RESULTS

While overall clinical outcomes exceeded national benchmarks across all places of admission in the sample, disparities were noted including higher cesarean birth rates among Black and Hispanic people. This variation was larger within the population of people who preferred to be admitted to the hospital in labor in the absence of medical indication.

CONCLUSION

This study supports that the birth center model provides safe delivery care across the intersections of US sociodemographics. Findings from this study highlight the importance of increased access and choice in place of birth for improving health equity, including decreasing cesarean birth and increasing breastfeeding initiation.

Salary and Workload of Midwives Across Birth Center Practice Types and State Regulatory Structures

INTRODUCTION

Expansion of the midwifery-led birth center model of care is one pathway to improving maternal and newborn health. There are a variety of practice types among birth centers and a range of state regulatory structures of midwifery practice across the United States. This study investigated how those variations relate to pay and workload for midwives at birth centers.

METHODS

Data from the American Association of Birth Centers Practice Survey and the Bureau of Labor Statistics' report on occupational employment and wage statistics were analyzed to explore how midwife salaries and workload at birth centers compare within and beyond the birth center model.

RESULTS

Survey results from 161 birth centers across the United States demonstrate wide variation in nurse-midwife salaries and are inconsistent with nurse-midwife salaries across all settings as reported by the Bureau of Labor Statistics. The reported number of hours worked by midwives within the birth center model is high. Salaries of midwives who work in birth center-only practices were consistently lower than salaries of midwives who worked in blended birth center and hospital practices, independent of the midwife's level of experience, geographic region of the country, and state regulatory structure.

DISCUSSION

Further research is needed to understand how to bring salaries and workload for midwives at birth centers into alignment with national averages.

A novel mark-recapture-recovery survey using genetic sampling for polar bears Ursus maritimus in Baffin Bay

Changes in sea-ice dynamics are affecting polar bears Ursus maritimus across their circumpolar range, which highlights the importance of periodic demographic assessments to inform management and conservation. We used genetic mark-recapture-recovery to derive estimates of abundance and survival for the Baffin Bay (BB) polar bear subpopulation—the first time this method has been used successfully for this species. Genetic data from tissue samples we collected via biopsy darting were combined with historical physical capture and harvest recovery data. The combined data set consisted of 1410 genetic samples (2011-2013), 914 physical captures (1993-1995, 1997), and 234 harvest returns of marked bears (1993-2013). The estimate of mean subpopulation abundance was 2826 (95% CI = 2284-3367) in 2012-2013. Estimates of annual survival (mean ± SE) were 0.90 ± 0.05 and 0.78 ± 0.06 for females and males age ≥2 yr, respectively. The proportion of total mortality of adult females and males that was attributed to legal harvest was 0.16 ± 0.05 and 0.26 ± 0.06, respectively. Remote sensing sea-ice data, telemetry data, and spatial distribution of onshore sampling indicated that polar bears were more likely to use offshore sea-ice habitat during the 1990s sampling period compared to the 2010s. Furthermore, in the 1990s, sampling of deep fjords and inland areas was limited, and no offshore sampling occurred in either time period, which precluded comparisons of abundance between the 1993-1997 and 2011-2013 study periods. Our findings demonstrate that genetic sampling can be a practical method for demographic assessment of polar bears over large spatial and temporal scales.

Invasive grass negatively affects growth and survival of an imperiled butterfly

With only ~1% of native prairie remaining in North America, populations of many prairie-obligate species, including the imperiled Dakota skipper butterfly, have drastically declined in recent decades. Unfortunately, population recovery is impeded by an insufficient understanding of Dakota skipper biology. Because larvae have never been naturally observed in the wild, even basic life history elements including preferred host plant(s) are not well understood, and potential hosts have been inferred from grasses inhabiting remnant sites rather than direct observations. To improve our understanding of Dakota skipper biology and habitat needs and inform recovery efforts, we conducted a no-choice performance experiment offering larvae 1 of 5 commonly occurring native grasses and 2 pervasive invasive grass species found across their historic range. We monitored larvae during key life history intervals and evaluated host plant quality by measuring larval and pupal mass, time to pupation, and survivorship. Larvae fed on all offered host grasses, but mass, phenology, and survivorship varied among treatments. Larvae reared on prairie dropseed and porcupine grass had the highest survival, the shortest time to adulthood, and the greatest mass, whereas larvae provided smooth brome and Kentucky bluegrass fared poorly for all observed metrics. All other grasses offered during the study were deemed ‘medium’ quality. Our results suggest that although larvae can feed on a variety of potential host plants, these hosts vary in quality. Invasive grasses across prairies in North America may pose an ecological trap to the conservation of Dakota skipper and other prairie-obligate Lepidoptera.

Birth Outcomes of Women with Obesity Enrolled for Care at Freestanding Birth Centers in the United States

Introduction

Current US guidelines for the care of women with obesity generalize obesity‐related risks to all women regardless of overall health status and assume that birth will occur in hospitals. Perinatal outcomes for women with obesity in US freestanding birth centers need documentation.

Methods

Pregnancies recorded in the American Association of Birth Centers Perinatal Data Registry were analyzed (n = 4,455) to form 2 groups of primiparous women (n = 964; 1:1 matching of women with normal body mass indices [BMIs] and women with obese BMIs [>30]), using propensity score matching to address the imbalance of potential confounders. Groups were compared on a range of outcomes. Differences between groups were evaluated using χ² test for categorical variables and Student's t test for continuous variables. Paired t test and McNemar's test evaluated the differences among the matched pairs.

Results

The majority of women with obese BMIs experienced uncomplicated perinatal courses and vaginal births. There were no significant differences in antenatal complications, proportion of prolonged pregnancy, prolonged first and second stage labor, rupture of membranes longer than 24 hours, postpartum hemorrhage, or newborn outcomes between women with obese BMIs and normal BMIs. Among all women with intrapartum referrals or transfers (25.3%), the primary indications were prolonged first stage or second stage (55.4%), inadequate pain relief (14.8%), client choice or psychological issue (7.0%), and meconium (5.3%). Primiparous women with obesity who started labor at a birth center had a 30.7% transfer rate and an 11.1% cesarean birth rate.

Discussion

Women with obese BMIs without medical comorbidity can receive safe and effective midwifery care at freestanding birth centers while anticipating a low risk for cesarean birth. The risks of potential, obesity‐related perinatal complications should be discussed with women when choosing place of birth; however, pregnancy complicated by obesity must be viewed holistically, not simply through the lens of obesity.

Rural resilience: The role of birth centers in the United States

PURPOSE

To explore the role of the birth center model of care in rural health and maternity care delivery in the United States.

METHODS

All childbearing families enrolled in care at an American Association of Birth Centers Perinatal Data Registry^TM user sites between 2012 and 2020 are included in this descriptive analysis.

FINDINGS

Between 2012 and 2020, 88 574 childbearing families enrolled in care with 82 American Association of Birth Centers Perinatal Data Registry^TM user sites. Quality outcomes exceeded national benchmarks across all geographic regions in both rural and urban settings. A stable and predictable rate of transfer to a higher level of care was demonstrated across geographic regions, with over half of the population remaining appropriate for birth center level of care throughout the perinatal episode of care. Controlling for socio demographic and medical risk factors, outcomes were as favorable for clients in rural areas compared with urban and suburban communities.

CONCLUSIONS

Rural populations cared for within the birth center model of care experienced high-quality outcomes.

HEALTH POLICY IMPLICATIONS

A major focus of the United States maternity care reform should be the expansion of access to birth center models of care, especially in underserved areas such as rural communities.

Improving the Experience of Care: Results of the American Association of Birth Centers Strong Start Client Experience of Care Registry Pilot Program, 2015-2016

In 2018, the Center for Medicare and Medicaid Innovation in the United States (US) released report demonstrating birth centers as the appropriate level of care for most Medicaid beneficiaries. A pilot project conducted at 34 American Association of Birth Centers (AABC) Strong Start sites included 553 beneficiaries between 2015 and 2016 to explore client perceptions of high impact components of care. Participants used the AABC client experience of care registry to report knowledge, values, and experiences of care. Data were linked to more than 300 process and outcome measures within the AABC Perinatal Data Registry™. Descriptive statistics, t tests, χ analysis, and analysis of variance were conducted. Participants demonstrated high engagement with care and trust in pregnancy, birth, and parenting. Beneficiaries achieved their preference for vaginal birth (89.9%) and breastfeeding at discharge through 6 weeks postpartum (91.7% and 87.6%). Beneficiaries reported having time for questions, felt listened to, spoken to in a way they understood, being involved in decision making, and treated with respect. There were no variations in experience of care, cesarean birth, or breastfeeding by race. Medicaid beneficiaries receiving prenatal care at AABC Strong Start sites demonstrated high levels of desired engagement and reported receiving respectful, accessible care and high-quality outcomes. More investment and research using client-reported data registries are warranted as the US works to improve the experience of perinatal care nationwide.

Abstract P4-08-31: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Loughman T, Wang C-JA, Dynoodt P, Fender B, Lopez-Ruiz C, Barron S, Stapleton S, O'Leary D, Fabre A, Quinn C, Nodin B, Jirström K, Bracken A, Gallagher WM. Withdrawn [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-08-31.

Screening for postpartum anxiety: A quality improvement project to promote the screening of women suffering in silence

BACKGROUND

Postpartum anxiety is a mental health problem that has largely been ignored by maternity care providers despite an estimated incidence as high as 28.9%. Though postpartum anxiety may or may not be accompanied by depression, and while screening for postpartum depression has become more common place, postpartum anxiety is often not assessed or addressed.

PURPOSE

The purpose of this pilot quality improvement project was to implement a screening, treatment and referral program for postpartum anxiety in the birth centre environment.

PROCEDURES

Midwives from 10 geographically diverse birth centres, and all members of the American Association of Birth Centres, were recruited to participate in the project. An online video was developed which detailed postpartum anxiety, screening through use of the anxiety subscale of the Edinburgh Postnatal Depression Scale and a toolkit for treatment and/or referral for screen positive patients. Participants entered patient scores into the Perinatal Data Registry of the American Association of Birth Centres. Individual interviews of midwives were conducted following the 10-week pilot period.

MAIN FINDINGS

There were a total of 387 participants across 9 participating sites. Among all screened participants with follow-up data, (n = 382), 9.69% (n = 37) were lost to follow-up. Among all participants screened with the Edinburgh Postpartum Depression Scale -3A and Edinburgh Postpartum Depression Scale (n = 318), 12.58% (n = 40) had a positive Edinburgh Postpartum Depression Scale -3A score of greater than six. Of all screened participants with an Edinburgh Postpartum Depression Scale score, 15 (6.98%) had a Edinburgh Postpartum Depression Scale score of less than 12 and an Edinburgh Postpartum Depression Scale -3A score greater than six, and would have not received follow up care if only screened for postpartum depression. Midwife participants expressed heightened awareness of the need to screen and felt screening was easy to integrate into clinical practice.

CONCLUSIONS

The Edinburgh Postpartum Depression Scale -3A is a valid, easy-to-use tool which should be considered for use in clinical practice. Modification of the electronic health record can serve as an important impetus triggering screening and treatment. It is important that clinicians are educated on the prevalence of postpartum anxiety, its risk factors, symptoms and implications.

Outcomes of childbearing Medicaid beneficiaries engaged in care at Strong Start birth center sites between 2012 and 2014

BACKGROUND

Variations in care for pregnant women have been reported to affect pregnancy outcomes.

METHODS

This study examined data for all 3136 Medicaid beneficiaries enrolled at American Association of Birth Centers (AABC) Center for Medicare and Medicaid Innovation Strong Start sites who gave birth between 2012 and 2014. Using the AABC Perinatal Data Registry, descriptive statistics were used to evaluate socio-behavioral and medical risks, and core perinatal quality outcomes. Next, the 2082 patients coded as low medical risk on admission in labor were analyzed for effective care and preference sensitive care variations. Finally, using binary logistic regression, the associations between selected care processes and cesarean delivery were explored.

RESULTS

Medicaid beneficiaries enrolled at AABC sites had diverse socio-behavioral and medical risk profiles and exceeded quality benchmarks for induction, episiotomy, cesarean, and breastfeeding. Among medically low-risk women, the model demonstrated effective care variations including 82% attendance at prenatal education classes, 99% receiving midwifery-led prenatal care, and 84% with midwifery- attended birth. Patient preferences were adhered to with 83% of women achieving birth at their preferred site of birth, and 95% of women using their preferred infant feeding method. Elective hospitalization in labor was associated with a 4-times greater risk of cesarean birth among medically low-risk childbearing Medicaid beneficiaries.

CONCLUSIONS

The birth center model demonstrates the capability to achieve the triple aims of improved population health, patient experience, and value.

Cesarean Outcomes in US Birth Centers and Collaborating Hospitals: A Cohort Comparison

INTRODUCTION

High rates of cesarean birth are a significant health care quality issue, and birth centers have shown potential to reduce rates of cesarean birth. Measuring this potential is complicated by lack of randomized trials and limited observational comparisons. Cesarean rates vary by provider type, setting, and clinical and nonclinical characteristics of women, but our understanding of these dynamics is incomplete.

METHODS

We sought to isolate labor setting from other risk factors in order to assess the effect of birth centers on the odds of cesarean birth. We generated low-risk cohorts admitted in labor to hospitals (n = 2527) and birth centers (n = 8776) using secondary data obtained from the American Association of Birth Centers (AABC). All women received prenatal care in the birth center and midwifery care in labor, but some chose hospital admission for labor. Analysis was intent to treat according to site of admission in spontaneous labor. We used propensity score adjustment and multivariable logistic regression to control for cohort differences and measured effect sizes associated with setting.

RESULTS

There was a 37% (adjusted odds ratio [OR], 0.63; 95% confidence interval [CI], 0.50-0.79) to 38% (adjusted OR, 0.62; 95% CI, 0.49-0.79) decreased odds of cesarean in the birth center cohort and a remarkably low overall cesarean rate of less than 5% in both cohorts.

DISCUSSION

These findings suggest that low rates of cesarean in birth centers are not attributable to labor setting alone. The entire birth center care model, including prenatal preparation and relationship-based midwifery care, should be studied, promoted, and implemented by policy makers interested in achieving appropriate cesarean rates in the United States.

Real-time high dynamic range laser scanning microscopy

In conventional confocal/multiphoton fluorescence microscopy, images are typically acquired under ideal settings and after extensive optimization of parameters for a given structure or feature, often resulting in information loss from other image attributes. To overcome the problem of selective data display, we developed a new method that extends the imaging dynamic range in optical microscopy and improves the signal-to-noise ratio. Here we demonstrate how real-time and sequential high dynamic range microscopy facilitates automated three-dimensional neural segmentation. We address reconstruction and segmentation performance on samples with different size, anatomy and complexity. Finally, in vivo real-time high dynamic range imaging is also demonstrated, making the technique particularly relevant for longitudinal imaging in the presence of physiological motion and/or for quantification of in vivo fast tracer kinetics during functional imaging.

Confocal and multiphoton fluorescence microscopy often suffers from low dynamic range. Here the authors develop a high dynamic range, laser scanning fluorescence technique by simultaneously recording different light intensity ranges. The method can be adapted to commercial systems.

Retrospective analysis of 49 cases of brain abscess and review of the literature

The case records of 49 patients discharged from St George's Hospital, London, between December 2000 and March 2004 with the diagnosis of brain abscess were reviewed in order to document the epidemiology, causes, treatment, and prognostic factors associated with brain abscess. Brain abscess occurred at all ages, more frequently in men than in women. Headache and altered mental status were common presenting symptoms. The frontal lobe was the most common site. Streptococcal infection was seen most commonly, but staphylococcal infection predominated in cases following neurosurgery. Computed tomography provided sufficient diagnostic information in most cases. All but five patients had early surgical drainage. Cefotaxime and metronidazole were used most often for empirical therapy. Thirty-nine patients recovered fully or had minimal incapacity. Five patients died. Patients with underlying cranial neoplasms or medical conditions had a worse outcome than those with a contiguous focus of infection or post-traumatic abscess. Changes in disease pattern were determined by comparison to a literature review. A PubMed search of the literature using the keywords "brain abscess" was undertaken, and identified papers and relevant citations were reviewed. Compared to earlier series, there was a marked decrease in the number of cases of brain abscess secondary to otitis media and congenital heart disease. There was an increase in the number of cases of brain abscess secondary to neurosurgery and trauma. Changes in the epidemiology of predisposing conditions for brain abscess are associated with changes in the patient population and causative organisms. Though still a potentially fatal infection, there have been recent improvements in diagnosis, treatment, and outcome.

Aneurysmal bone cyst of the spine

The authors present the case of an 11-year-old boy with a painful, rapidly expanding lesion in the posterior triangle of the neck. There was no history of cervical trauma. Computerized tomography of the neck revealed a unicameral (single-chambered) aneurysmal bone cyst involving the C3 vertebra. Treatment was by open resection and curettage; no recurrence was seen at six months. We discuss the natural history, differential diagnosis, radiographic appearance and treatment modalities for this unusual, benign, expanding, osteolytic lesion containing blood-filled cystic cavities.

Implementation of random set-up errors in Monte Carlo calculated dynamic IMRT treatment plans

The fluence-convolution method for incorporating random set-up errors (RSE) into the Monte Carlo treatment planning dose calculations was previously proposed by Beckham et al, and it was validated for open field radiotherapy treatments. This study confirms the applicability of the fluence-convolution method for dynamic intensity modulated radiotherapy (IMRT) dose calculations and evaluates the impact of set-up uncertainties on a clinical IMRT dose distribution. BEAMnrc and DOSXYZnrc codes were used for Monte Carlo calculations. A sliding window IMRT delivery was simulated using a dynamic multi-leaf collimator (DMLC) transport model developed by Keall et al. The dose distributions were benchmarked for dynamic IMRT fields using extended dose range (EDR) film, accumulating the dose from 16 subsequent fractions shifted randomly. Agreement of calculated and measured relative dose values was well within statistical uncertainty. A clinical seven field sliding window IMRT head and neck treatment was then simulated and the effects of random set-up errors (standard deviation of 2 mm) were evaluated. The dose-volume histograms calculated in the PTV with and without corrections for RSE showed only small differences indicating a reduction of the volume of high dose region due to set-up errors. As well, it showed that adequate coverage of the PTV was maintained when RSE was incorporated. Slice-by-slice comparison of the dose distributions revealed differences of up to 5.6%. The incorporation of set-up errors altered the position of the hot spot in the plan. This work demonstrated validity of implementation of the fluence-convolution method to dynamic IMRT Monte Carlo dose calculations. It also showed that accounting for the set-up errors could be essential for correct identification of the value and position of the hot spot.

Results of the National Study of Vaginal Birth After Cesarean in Birth Centers

OBJECTIVE

Some women wish to avoid a repeat cesarean delivery and believe that a midwife-supported vaginal birth after cesarean (VBAC) in a nonhospital setting represents their best chance to do so; there is a small, persistent demand for out-of-hospital VBACs. We conducted a study to obtain the data necessary to formulate an evidence-based policy on this practice.

METHODS

We prospectively collected data on pregnancy outcomes of 1,913 women intending to attempt VBACs in 41 participating birth centers between 1990 and 2000.

RESULTS

A total of 1,453 of the 1,913 women presented to the birth center in labor. Twenty-four percent of them were transferred to hospitals during labor; 87% of these had vaginal births. There were 6 uterine ruptures (0.4%), 1 hysterectomy (0.1%), 15 infants with 5-minute Apgar scores less than 7 (1.0%), and 7 fetal/neonatal deaths (0.5%). Most fetal deaths (5/7) occurred in women who did not have uterine ruptures. Half of uterine ruptures and 57% of perinatal deaths involved the 10% of women with more than 1 previous cesarean delivery or who had reached a gestational age of 42 weeks. Rates of uterine rupture and fetal/neonatal death were 0.2% each in women with neither of these risks.

CONCLUSION

Despite a high rate of vaginal births and few uterine ruptures among women attempting VBACs in birth centers, a cesarean-scarred uterus was associated with increases in complications that require hospital management. Therefore, birth centers should refer women who have undergone previous cesarean deliveries to hospitals for delivery. Hospitals should increase access to in-hospital care provided by midwife/obstetrician teams during VBACs.

LEVEL OF EVIDENCE

III.

"Anorexia saved my life": coincidental anorexia nervosa and cerebral meningioma

OBJECTIVE

We report on a 13-year-old girl with coincidental occult intracranial tumor and early-onset anorexia nervosa.

METHOD

The cerebral meningioma was discovered fortuitously as the result of a research project using SPECT imaging to locate a neurobiological substrate in patients with anorexia nervosa. Without SPECT, the meningioma would have remained undiagnosed until it had become symptomatic. The two conditions appear to have been completely unrelated.

RESULTS AND DISCUSSION

The case highlights two important points. First, intracranial pathology should also be considered however certain is the diagnosis of early-onset anorexia nervosa. Second, neuroimaging plays an important part in diagnosing early-onset anorexia nervosa, both from a clinical and a research prospective.

Gliomatosis cerebri: pitfalls in diagnosis

We report two young patients with obscure presentations of gliomatosis cerebri. Initial CT scanning was inconclusive and in one case showed intraventricular haemorrhage, a feature not previously described. Magnetic resonance imaging was required to show the lesions with greater definition; however, in both cases, a biopsy was needed to confirm the diagnosis.

Acquired immune deficiency syndrome (AIDS) and cerebral astrocytoma

The presence of cerebral lesions in patients affected by the acquired immune deficiency syndrome (AIDS) has been estimated to be around 10%, with the majority being infective lesions or primary central nervous system lymphomas. The co-occurrence of a cerebral glioma in such patients is rare. The aim of this report is to present four more cases, discussing their clinical and neuroradiological features, as well as the outcome and the possible pathogenesis.

Continuous arteriovenous hemofiltration: an alternative dialysis therapy in neonates

Modifications have made it possible to perform CAVH in the neonate. One of these is decreasing the extravascular volume in the tubing and filter to a minimal amount to allow for adequate intravascular blood volume in the infant. Another is utilizing predilutional fluid to decrease the need for heparinization. A third modification is utilizing the suction-assist pumps to help control the amount of fluid removed from the infant. With modifications of this system to fit the special needs of neonates and intensive nursing and medical management, CAVH can be a successful alternative to traditional dialysis therapies in neonates.

Outcomes of care in birth centers. The National Birth Center Study

We studied 11,814 women admitted for labor and delivery to 84 free-standing birth centers in the United States and followed their course and that of their infants through delivery or transfer to a hospital and for at least four weeks thereafter. The women were at lower-than-average risk of a poor outcome of pregnancy, according to many but not all of the recognized demographic and behavioral risk factors. Among the women, 70.7 percent had only minor complications or none; 7.9 percent had serious emergency complications during labor and delivery or soon thereafter, such as thick meconium or severe shoulder dystocia. One woman in six (15.8 percent) was transferred to a hospital; 2.4 percent had emergency transfers. Twenty-nine percent of nulliparous women and only 7 percent of parous women were transferred, but the frequency of emergency transfers was the same. The rate of cesarean section was 4.4 percent. There were no maternal deaths. The overall intrapartum and neonatal mortality rate was 1.3 per 1000 births. The rates of infant mortality and low Apgar scores were similar to those reported in large studies of low-risk hospital births. We conclude that birth centers offer a safe and acceptable alternative to hospital confinement for selected pregnant women, particularly those who have previously had children, and that such care leads to relatively few cesarean sections.