Mark Santillan

The association between hospital obstetrical volume and maternal postpartum complications

OBJECTIVE The purpose of this study was to examine the relationship between delivery volume and maternal complications. STUDY DESIGN We used administrative data to identify women who had been admitted for childbirth in 2006. Hospitals were stratified into deciles that were based on delivery volume. We compared composite complication rates across deciles. RESULTS We evaluated 1,683,754 childbirths in 1045 hospitals. Decile 1 and 2 hospitals had significantly higher rates of composite complications than decile 10 (11.8% and 10.1% vs 8.5%, respectively; P < .0001). Decile 9 and 10 hospitals had modestly higher composite complications as compared with decile 6 (8.8% and 8.5% vs 7.6%, respectively; P < .0001). Sixty percent of decile 1 and 2 hospitals were located within 25 miles of the nearest greater volume hospital. CONCLUSION Women who deliver at very low-volume hospitals have higher complication rates, as do women who deliver at exceedingly high-volume hospitals. Most women who deliver in extremely low-volume hospitals have a higher volume hospital located within 25 miles.

Vasopressin in Preeclampsia A Novel Very Early Human Pregnancy Biomarker and Clinically Relevant Mouse Model

Preeclampsia, a cardiovascular disorder of late pregnancy, is characterized as a low-renin hypertensive state relative to normotensive pregnancy. Because other nonpregnant low-renin hypertensive disorders often exhibit and are occasionally dependent on elevated arginine vasopressin (AVP) secretion, we hypothesized a possible use for plasma AVP measurements in the prediction of preeclampsia. Copeptin is an inert prosegment of AVP that is secreted in a 1:1 molar ratio and exhibits a substantially longer biological half-life compared with AVP, rendering it a clinically useful biomarker of AVP secretion. Copeptin was measured throughout pregnancy in maternal plasma from preeclamptic and control women. Maternal plasma copeptin was significantly higher throughout preeclamptic pregnancies versus control pregnancies. While controlling for clinically significant confounders (age, body mass index, chronic essential hypertension, twin gestation, diabetes mellitus, and history of preeclampsia) using multivariate regression, the association of higher copeptin concentration and the development of preeclampsia remained significant. Receiver operating characteristic analyses reveal that as early as the sixth week of gestation, elevated maternal plasma copeptin concentration is a highly significant predictor of preeclampsia throughout pregnancy. Finally, chronic infusion of AVP during pregnancy (24 ng per hour) is sufficient to phenocopy preeclampsia in C57BL/6J mice, causing pregnancy-specific hypertension, renal glomerular endotheliosis, proteinuria, and intrauterine growth restriction. These data implicate AVP release as a novel predictive biomarker for preeclampsia very early in pregnancy, identify chronic AVP infusion as a novel and clinically relevant model of preeclampsia in mice, and are consistent with a potential causative role for AVP in preeclampsia in humans.Preeclampsia, a cardiovascular disorder of late pregnancy, is characterized as a low-renin hypertensive state relative to normotensive pregnancy. Because other nonpregnant low-renin hypertensive disorders often exhibit and are occasionally dependent on elevated arginine vasopressin (AVP) secretion, we hypothesized a possible use for plasma AVP measurements in the prediction of preeclampsia. Copeptin is an inert prosegment of AVP that is secreted in a 1:1 molar ratio and exhibits a substantially longer biological half-life compared with AVP, rendering it a clinically useful biomarker of AVP secretion. Copeptin was measured throughout pregnancy in maternal plasma from preeclamptic and control women. Maternal plasma copeptin was significantly higher throughout preeclamptic pregnancies versus control pregnancies. While controlling for clinically significant confounders (age, body mass index, chronic essential hypertension, twin gestation, diabetes mellitus, and history of preeclampsia) using multivariate regression, the association of higher copeptin concentration and the development of preeclampsia remained significant. Receiver operating characteristic analyses reveal that as early as the sixth week of gestation, elevated maternal plasma copeptin concentration is a highly significant predictor of preeclampsia throughout pregnancy. Finally, chronic infusion of AVP during pregnancy (24 ng per hour) is sufficient to phenocopy preeclampsia in C57BL/6J mice, causing pregnancy-specific hypertension, renal glomerular endotheliosis, proteinuria, and intrauterine growth restriction. These data implicate AVP release as a novel predictive biomarker for preeclampsia very early in pregnancy, identify chronic AVP infusion as a novel and clinically relevant model of preeclampsia in mice, and are consistent with a potential causative role for AVP in preeclampsia in humans. # Novelty and Significance {#article-title-45}

Pregnant mice lacking indoleamine 2,3-dioxygenase exhibit preeclampsia phenotypes

Preeclampsia is a cardiovascular disorder of late pregnancy that is, commonly characterized by hypertension, renal structural damage and dysfunction, and fetal growth restriction. Prevailing etiologic models of this disorder include T‐cell dysfunction as an initiating cause of preeclampsia. Indoleamine 2,3‐dioxygenase (IDO), an enzyme that mediates the conversion of tryptophan to kynurenine, has been linked to preeclampsia in humans, and is known to regulate T‐cell activity and an endothelial‐derived relaxing factor. To test the hypothesis that IDO is causally involved in the pathogenesis of preeclampsia, mice deficient for IDO (IDO‐KO) were generated on a C57BL/6 background. IDO‐KO and wild‐type C57BL/6 mice were bred, and preeclampsia phenotypes were evaluated during pregnancy. Pregnant IDO‐KO mice exhibited pathognomonic renal glomerular endotheliosis, proteinuria, pregnancy‐specific endothelial dysfunction, intrauterine growth restriction, and mildly elevated blood pressure compared to wild‐type mice. Together these findings highlight an important role for IDO in the generation of phenotypes typical of preeclampsia. Loss of IDO function may represent a risk factor for the development of preeclampsia. By extension, increased IDO activity, reductions in IDO reactants, or increases in IDO products may represent novel therapeutic approaches for this disorder.

Noninvasive fetal genome sequencing: a primer

We recently demonstrated whole genome sequencing of a human fetus using only parental DNA samples and plasma from the pregnant mother. This proof‐of‐concept study demonstrated how samples obtained noninvasively in the first or second trimester can be analyzed to yield a highly accurate and substantially complete genetic profile of the fetus, including both inherited and de novo variation. Here, we revisit our original study from a clinical standpoint, provide an overview of the scientific approach, and describe opportunities and challenges along the path toward clinical adoption of noninvasive fetal whole genome sequencing.

Forceps delivery volumes in teaching and Nonteaching hospitals: Are volumes sufficient for physicians to acquire and maintain competence?

Purpose The decline in the use of forceps in operative deliveries over the last two decades raises questions about teaching hospitals’ ability to provide trainees with adequate experience in the use of forceps. The authors examined (1) the number of operative deliveries performed in teaching and nonteaching hospitals, and (2) whether teaching hospitals performed a sufficient number of forceps deliveries for physicians to acquire and maintain competence. Method The authors used State Inpatient Data from nine states to identify all women hospitalized for childbirth in 2008. They divided hospitals into three categories: major teaching, minor teaching, and nonteaching. They calculated delivery volumes (total operative, cesarean, vacuum, forceps, two or more methods) for each hospital and compared data across hospital categories. Results The sample included 1,344,305 childbirths in 835 hospitals. The mean cesarean volumes for major teaching, minor teaching, and nonteaching hospitals were 969.8, 757.8, and 406.9. The mean vacuum volumes were 301.0, 304.2, and 190.4, and the mean forceps volumes were 25.2, 15.3, and 8.9. In 2008, 31 hospitals (3.7% of all hospitals) performed no vacuum extractions, and 320 (38.3%) performed no forceps deliveries. In 2008, 13 (23%) major teaching and 44 (44%) minor teaching hospitals performed five or fewer forceps deliveries. Conclusions Low forceps delivery volumes may preclude many trainees from acquiring adequate experience and proficiency. These findings highlighted broader challenges, faced by many specialties, in ensuring that trainees and practicing physicians acquire and maintain competence in infrequently performed, highly technical procedures.

Non-invasive fetal genome sequencing: Opportunities and challenges†

We recently predicted the whole genome sequence of a human fetus using samples obtained non-invasively from the pregnant mother and the father. [Kitzman et al., 2012] This advance raises the possibility that it may soon be possible to perform genome-wide prenatal genetic testing without an invasive procedure early in pregnancy. Such a test would substantially broaden the scope of fetal genetic results that could be available prenatally. Non-invasive fetal genome sequencing (NIFGS) does not inherently raise new ethical issues, or those that cannot be addressed within the existing framework of medical bioethics. Indeed, many of the same issues have been raised by the introduction of other prenatal testing / screening technologies, now in wide use, and again more recently by the introduction of whole genome sequencing for clinical diagnosis. [Sayres et al., 2011, Schmitz et al., 2009, Ravitsky, 2009, Benn et al., 2009, Tabor et al., 2011, Berg et al., 2011] However, the ethical issues are, somewhat, magnified by the possibility of NIFGS and compounded by controversies surrounding elective pregnancy termination, rights of individuals with disabilities, and eugenics. Accordingly, the prospect of successful NIFGS, even on a research basis, is likely to generate considerable controversy and debate about the acceptability of developing such technologies, much less if and how they should be used. We view this response as very positive because it provides all stakeholders and the broader public in general with the opportunity to carefully consider and deliberate these issues in what we would hope is a thoughtful and balanced way. As NIFGS becomes technically tractable and increasingly cost-effective, and as an acceptable false positive/false negative profile is achieved, one population for which it might be of great benefit may be pregnant women who are currently offered invasive prenatal diagnostic testing. Such women are typically at risk for genetic conditions based on screening results or family history, and NIFGS would likely reduce if not eliminate adverse outcomes from invasive testing for most of these women. The expanded use of NIFGS would present several advantages and challenges. Broader use of NIFGS might lead to the greater detection of Mendelian disorders in families who would not otherwise have been offered prenatal testing, as well as families who might have refused invasive testing because of risks to the pregnancy and fetus. NIFGS could augment or even replace current approaches to neonatal screening as most such disorders are autosomal or X-linked recessive (e.g., hypothyroidism and congenital hearing loss are only sometimes Mendelian). Prenatal identification of disorders now found in neonatal screening would afford for earlier parental education, diminished false positives and the accompanying costs of retesting and parental anxiety and earlier therapeutic interventions. Earlier detection of such disorders would also foster improved prenatal care, pregnancy and delivery management and/or postnatal intervention. For example, 90% of genetic variants in SCNA1 that cause seizure disorders are de novo, and identification by NIFGS could allow for diagnosis before the onset of seizures and consideration of appropriate precautions and/or pharmacological treatment. [Marini et al., 20011] Similarly, 50% of mutations causing Multiple Endocrine Neoplasia 2B are spontaneous, and earlier identification of these mutations could prompt prophylactic thyroidectomy and improve outcomes. [Carlson et al., 1994] The availability of NIFGS could increase the utilization of prenatal testing, and in turn increase rates of elective termination, both for disorders for which testing is currently available and for the wide arrange of disorders and traits for which testing would be newly available. [Tischler et al., 2011] On the other hand, NIFGS might also make pregnancy termination safer, less costly, and less traumatic as it could be performed early in gestation. Broad use of NIFGS might result in increased societal pressure for pregnant women to undergo screening and terminate any fetus suspected to have a Mendelian condition. This could reverse important and continuing social progress towards civil rights and social support for people and families with disabilities. In addition, this societal pressure might threaten parental autonomy over reproductive decision-making. Broader use of NIFGS might also create or magnify social stigmas or inequities. NIFGS would likely remain expensive and may not be reimbursable by insurance in the short-term. This might exaggerate disparities between people who can easily afford access and those who cannot. If access is limited to those who can afford it, it is possible that a disproportionate number of lower income families could suffer from the higher rates of morbidity and mortality of invasive testing. In the extreme scenario, children with Mendelian conditions would be disproportionately born to lower income families that could not afford NIFGS. Such a disparity would likely further stigmatize many of these conditions and exaggerate existing disparities in access to healthcare and benefits for these populations. Another key issue raised by NIFGS is that it represents a substantially more comprehensive test for Mendelian disorders with a known cause, and will identify variants that are beyond the scope of conventional prenatal screening and diagnosis. Specifically, variants will be identified that indicate increased risk for developing adult onset conditions. This is not unique to NIFGS: in fact this is an ongoing challenge in pediatric clinical genetic testing. [Wilfond et al., 2009] Such information may be irrelevant or inappropriate to return for the benefit of the fetus/future child, but may have direct implications for the health of the parent, and therefore provide indirect benefit to any current or future children. However, if NIFGS is more broadly implemented, the scope of the results identified and the number of individuals affected may increase substantially. This will further overwhelm the existing infrastructure for providing genetic counseling. As with other applications of whole-genome sequencing, NIFGS will identify variants of ambiguous clinical utility in genes known to be associated with both pediatric and adult complex disease. For example, Kitzman et al. found a de novo novel missense variant in ACMSD, a gene in which common variants have been associated with Parkinson disease by genome-wide association. [Klitzman et al., 2012, International Parkinson Disease Genomics Consortium et al., 2011] This variant causes substitution of a highly conserved amino acid residue, but in the absence of compelling evidence of its role in Parkinson disease or other conditions, its detection is of limited clinical value. While this is no different than the challenge of interpreting WGS information in general, pregnancy might be a particularly vulnerable time in which to receive this information and parents might feel compelled to give more credence to the information than it warrants. There are several other important issues that require consideration. Will the non-invasive nature of this test, combined with the enhanced detection of Mendelian disorders, lead to a substantial increase in the number of women who consider prenatal diagnosis? How will the medical community meet the challenge of providing genetic counseling to address the complex nature of the information that may be identified? These concerns raise the possibility that some women may not be able to provide adequate informed consent, or may proceed with actions such as terminations without complete understanding of the test results or the prognosis for various rare Mendelian disorders. If NIFGS allows the creation of a record of a child’s whole genome prior to its birth, what should happen to that data? Should it be stored as part of the child’s medical record, with the possibility for future updating, analysis and mining for medically relevant information? Or should it be destroyed? Who should make this decision and have control over the data? As with many new technologies, NIFGS will be accompanied by many ethical and social challenges. We think that it is imperative that these questions and issues be discussed and addressed by a diverse group of stakeholders, as well as through collection of empirical data on stakeholder perspectives and concerns. Much can be learned from the history of the implementation of other prenatal testing approaches, such as amniocentesis and CVS, as well as the ongoing debates about pediatric genetic testing and return of results from whole genome sequencing. [Rapp, 2000]

Efficacy of polymeric encapsulated C5a peptidase–based group B streptococcus vaccines in a murine model

OBJECTIVE The purpose was to examine in mice the efficacy of various polymeric-encapsulated C5a peptidase vaccine formulations in eliciting a long-term immune response and preventing group B streptococcus (GBS) infection. STUDY DESIGN C5a peptidase was encapsulated in semipermeable microspheres of poly(lactide-coglycolide) (PLGA). Female ICR mice were immunized with 0, 10, or 30 μg of encapsulated C5a peptidase within 2 different formulations of PLGA polymers. Booster doses were given at weeks 4 and 8. Antibody responses were measured by enzyme-linked immunosorbent assay at weeks 4, 8, 11, and 40. Vaginal challenges with GBS types 1a, III, and V were performed at week 12. RESULTS Thirty microgram doses of the 75:25 and 50:50 PLGA formulations generate the highest and most sustained C5a peptidase-specific immune responses. Mice that received encapsulated C5a peptidase were significantly protected from vaginal colonization compared with mice that received empty microspheres. CONCLUSION Encapsulated C5a peptidase elicited significant immune responses and protection against a GBS challenge. C5a peptidase microsphere encapsulation has potential as a GBS vaccine.

Aspirin inhibits expression of sFLT1 from human cytotrophoblasts induced by hypoxia, via cyclo-oxygenase 1

INTRODUCTION Elevated circulating soluble FLT1 (sFLT1) levels seen in preeclampsia may play a role in its development. Aspirin is recommended for prevention of preeclampsia. We hypothesized that aspirin may inhibit the production of sFlt1. METHODS Placentas from women with and without preeclampsia were collected. Primary cytotrophoblasts (CTBs) were cultured from normal placentas and treated with aspirin, sc-560, a COX1 inhibitor or celecoxib, a COX2 inhibitor. The expression of sFLT1, FLT1, COX1 and COX2 was studied. The effect of aspirin on sFlt1 expression was also studied in HEK293 cells and in HTR-8/SVNeo cells. RESULTS The expression of sFLT1 was increased in preeclamptic placentas compared to control placentas and the expression and release of sFLT1 increased in CTBs exposed to 2% O2 compared to controls. Aspirin at 3 and 12 mM concentration reduced the expression and release of sFLT1 in CTBs. Aspirin also inhibited sFlt1 expression from HTR-8/SVNeo and HEK293 cells. Sc-560, but not celecoxib, reduced sFLT1 expression and release from CTBs. Aspirin and sc-560 also reduced hypoxia-induced FLT1 mRNA expression and inhibited COX1 mRNA in CTBs. DISCUSSION This study confirms that sFLT1 expression is increased in preeclamptic placentas and in CTBs exposed to hypoxia. Aspirin inhibits the production sFLT1 in CTBs and in HTR-8/SVNeo. Sc-560 recapitulated the effects of aspirin on sFLT1 expression and release in CTBs suggesting that the aspirin effect may be mediated via inhibition of COX1. The study increases our understanding of the mechanisms regulating sFlt1 expression and provides a plausible explanation for the effect of aspirin to prevent preeclampsia.

Cell encapsulation as a potential nondietary therapy for maternal phenylketonuria

OBJECTIVE The objective of this work was to determine whether cells overexpressing phenylalanine (Phe) hydroxylase (PAH) can significantly reduce Phe in vitro for potential use as a therapy for preventing maternal phenylketonuria. STUDY DESIGN Human 293T and WRL68 cell lines were transiently and stably transfected to overexpress PAH. Cells were encapsulated within microspheres of sodium alginate. Timed measurements of Phe in media were performed using tandem mass spectrometry. RESULTS Both nonencapsulated and encapsulated transiently transfected cells overexpressing PAH significantly reduced the Phe concentration in media by approximately 50% in comparison to mock-transfected cells. Cell line clones stably expressing PAH significantly decreased the Phe concentration in the media by up to 85% compared with media alone. CONCLUSION Both unencapsulated and encapsulated cells overexpressing PAH significantly reduce Phe in vitro. Studies using phenylketonuria model mice will be important in determining the ability of our therapy to prevent the teratogenic effects of elevated maternal Phe in maternal phenylketonuria.

Dopaminergic Toxin 1-Methyl-4-Phenylpyridinium, Proteins α-Synuclein and Glia Maturation Factor Activate Mast Cells and Release Inflammatory Mediators

Parkinson’s disease (PD) is characterized by the presence of Lewy bodies and degeneration of dopaminergic neurons. 1-methyl-4-phenylpyridinium (MPP+), a metabolite of neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and Lewy body component α-synuclein activates glia in PD pathogenesis. Mast cells and glia maturation factor (GMF) are implicated in neuroinflammatory conditions including Multiple Sclerosis. However, the role of mast cells in PD is not yet known. We have analyzed the effect of recombinant GMF, MPP+, α-synuclein and interleukin-33 (IL-33) on mouse bone marrow-derived cultured mast cells (BMMCs), human umbilical cord blood-derived cultured mast cells (hCBMCs) and mouse brain-derived cultured astrocytes by quantifying cytokines/chemokines released using ELISA or by detecting the expression of co-stimulatory molecules CD40 and CD40L by flow cytometry. GMF significantly released chemokine (C-C motif) ligand 2 (CCL2) from BMMCs but its release was reduced in BMMCs from GMF knockout mice. GMF, α-synuclein and MPP+ released IL-1β, β-hexosaminidase from BMMCs, and IL-8 from hCBMCs. GMF released CCL5, and IL-33- induced the expression of GMF from hCBMCs. Novel GMF expression was detected in hCBMCs and BMMCs by immunocytochemistry. GMF released tumor necrosis factor-alpha (TNF-α) from mouse astrocytes, and this release was greater in BMMC- astrocyte coculture than in individual cultures. Flow cytometry results showed increased IL-33 expression by GMF and MPP+, and GMF-induced CD40 expression in astrocytes. Proinflammatory mediator release by GMF, MPP+ and α-synuclein, as well as GMF expression by mast cells indicate a potential therapeutic target for neurodegenerative diseases including PD.