A Randomized Controlled Trial of the Safety and Immunogenicity of Tetanus, Diphtheria, and Acellular Pertussis Vaccine Immunization During Pregnancy and Subsequent Infant Immune Response

Background

Immunization of pregnant women with tetanus-diphtheria-acellular pertussis vaccine (Tdap) provides protection against pertussis to the newborn infant.

Methods

In a randomized, controlled, observer-blind, multicenter clinical trial, we measured the safety and immunogenicity of Tdap during pregnancy and the effect on the infant's immune response to primary vaccination at 2, 4, and 6 months and booster vaccination at 12 months of age. A total of 273 women received either Tdap or tetanus-diphtheria (Td) vaccine in the third trimester and provided information for the safety analysis and samples for the immunogenicity analyses; 261 infants provided serum for the immunogenicity analyses.

Results

Rates of adverse events were similar in both groups. Infants of Tdap recipients had cord blood levels that were 21% higher than maternal levels for pertussis toxoid (PT), 13% higher for filamentous hemagglutinin (FHA), 4% higher for pertactin (PRN), and 7% higher for fimbriae (FIM). These infants had significantly higher PT antibody levels at birth and at 2 months and significantly higher FHA, PRN, and FIM antibodies at birth and 2 and 4 months, but significantly lower PT and FHA antibody levels at 6 and 7 months and significantly lower PRN and FIM antibody levels at 7 months than infants whose mothers received Td. Differences persisted prebooster at 12 months for all antigens and postbooster 1 month later for PT, FHA, and FIM.

Conclusions

This study demonstrated that Tdap during pregnancy results in higher levels of antibodies early in infancy but lower levels after the primary vaccine series.

Clinical Trials Registration

NCT00553228.

No. 96-The Reproductive Care of Women Living With Hepatitis C Infection

OBJECTIVE

hepatitis C virus (HCV) is an increasingly important public health problem worldwide. Health care workers providing care to women of childbearing age are uniquely placed in their practices to identify a significant proportion of at-risk patients and to provide appropriate screening and counselling. The primary objective of this guideline is to provide accurate, current information to those offering reproductive care to women living with HCV. This document is also intended to raise awareness of HCV in both the medical and general populations.

OPTIONS

the areas of clinical practice considered in formulating this guideline are disease prevention, targeted screening of individuals at risk of contracting HCV, management of identified patients in the context of reproductive care, and the appropriate referral of patients to those with particular expertise.

OUTCOMES

implementation of these guidelines should facilitate identification of infected individuals. It should also result in improved physical and mental well-being for patients and their families and reduction in transmission rates.

EVIDENCE

the literature between 1966 and 2000, including non- English language publications, was extensively searched utilizing Medline. A multidisciplinary group consisting of experts within the fields of obstetrics and gynaecology, infectious diseases, hepatology, and public health convened in Montreal in February 2000. The working group also included a patient and a representative from the Hepatitis C Society of Canada. The level of evidence for the recommendations has been determined using the criteria described by the Canadian Task Force on Periodic Health Examination.

BENEFITS, HARMS AND COSTS

the public health benefits of increased identification of at-risk individuals, diagnosis, treatment, implementation of risk reduction behaviours, and reduced transmission rates, both on an individual and at the community level, are significant. However, it must be remembered that the diagnosis of a chronic disease may have far reaching effects for the individual patient and her family.

RECOMMENDATIONS

VALIDATION: references were collected through Medline searches and comparison made to existing current guidelines for assessment of consistency. External reviewers expert in their field were also consulted.

Vaccinium angustifolium (lowbush blueberry) leaf extract increases extravillous trophoblast cell migration and invasion in vitro

Perturbations to extravillous trophoblast (EVT) cell migration and invasion are associated with the development of placenta-mediated diseases. Phytochemicals found in the lowbush blueberry plant (Vaccinium angustifolium) have been shown to influence cell migration and invasion in models of tumorigenesis and noncancerous, healthy cells, however never in EVT cells. We hypothesized that the phenolic compounds present in V. angustifolium leaf extract promote trophoblast migration and invasion. Using the HTR-8/SVneo human EVT cell line and Boyden chamber assays, the influence of V. angustifolium leaf extract (0 to 2 × 10⁴  ng/ml) on trophoblast cell migration (n = 4) and invasion (n = 4) was determined. Cellular proliferation and viability were assessed using immunoreactivity to Ki67 (n = 3) and trypan blue exclusion assays (n = 3), respectively. At 20 ng/ml, V. angustifolium leaf extract increased HTR-8/SVneo cell migration and invasion (p < .01) and did not affect cell proliferation or viability. Chlorogenic acid was identified as a major phenolic compound of the leaf extract and the most active compound. Evidence from Western blot analysis (n = 3) suggests that the effects of the leaf extract and chlorogenic acid on trophoblast migration and invasion are mediated through an adenosine monophosphate-activated protein (AMP) kinase-dependent mechanism. Further investigations examining the potential therapeutic applications of this natural health product extract and its major chemical compounds in the context of placenta-mediated diseases are warranted.

Can adverse maternal and perinatal outcomes be predicted when blood pressure becomes elevated? Secondary analyses from the CHIPS (Control of Hypertension In Pregnancy Study) randomized controlled trial

Introduction

For women with chronic or gestational hypertension in CHIPS (Control of Hypertension In Pregnancy Study, NCT01192412), we aimed to examine whether clinical predictors collected at randomization could predict adverse outcomes.

Material and methods

This was a planned, secondary analysis of data from the 987 women in the CHIPS Trial. Logistic regression was used to examine the impact of 19 candidate predictors on the probability of adverse perinatal (pregnancy loss or high level neonatal care for >48 h, or birthweight <10th percentile) or maternal outcomes (severe hypertension, preeclampsia, or delivery at <34 or <37 weeks). A model containing all candidate predictors was used to start the stepwise regression process based on goodness of fit as measured by the Akaike information criterion. For face validity, these variables were forced into the model: treatment group (“less tight” or “tight” control), antihypertensive type at randomization, and blood pressure within 1 week before randomization. Continuous variables were represented continuously or dichotomized based on the smaller p‐value in univariate analyses. An area‐under‐the‐receiver‐operating‐curve (AUC ROC) of ≥0.70 was taken to reflect a potentially useful model.

Results

Point estimates for AUC ROC were <0.70 for all but severe hypertension (0.70, 95% CI 0.67–0.74) and delivery at <34 weeks (0.71, 95% CI 0.66–0.75). Therefore, no model warranted further assessment of performance.

Conclusions

CHIPS data suggest that when women with chronic hypertension develop an elevated blood pressure in pregnancy, or formerly normotensive women develop new gestational hypertension, maternal and current pregnancy clinical characteristics cannot predict adverse outcomes in the index pregnancy.

Do labetalol and methyldopa have different effects on pregnancy outcome? Analysis of data from the Control of Hypertension In Pregnancy Study (CHIPS) trial

OBJECTIVE

To compare pregnancy outcomes, accounting for allocated group, between methyldopa-treated and labetalol-treated women in the CHIPS Trial (ISRCTN 71416914) of 'less tight' versus 'tight' control of pregnancy hypertension.

DESIGN

Secondary analysis of CHIPS Trial cohort.

SETTING

International randomised controlled trial (94 sites, 15 countries).

POPULATION OR SAMPLE

Of 987 CHIPS recruits, 481/566 (85.0%) women treated with antihypertensive therapy at randomisation. Of 981 (99.4%) women followed to delivery, 656/745 (88.1%) treated postrandomisation.

METHODS

Logistic regression to compare outcomes among women who took methyldopa or labetalol, adjusted for the influence of baseline factors.

MAIN OUTCOME MEASURES

CHIPS primary (perinatal loss or high level neonatal care for >48 hours) and secondary (serious maternal complications) outcomes, birthweight <10th centile, severe maternal hypertension, pre-eclampsia and delivery at <34 or <37 weeks.

RESULTS

Methyldopa and labetalol were used commonly at randomisation (243/987, 24.6% and 238/987, 24.6%, respectively) and post-randomisation (224/981, 22.8% and 433/981, 44.1%, respectively). Following adjusted analyses, methyldopa (versus labetalol) at randomisation was associated with fewer babies with birthweight <10th centile [adjusted odds ratio (aOR) 0.48; 95% CI 0.20-0.87]. Methyldopa (versus labetalol) postrandomisation was associated with fewer CHIPS primary outcomes (aOR 0.64; 95% CI 0.40-1.00), birthweight <10th centile (aOR 0.54; 95% CI 0.32-0.92), severe hypertension (aOR 0.51; 95% CI 0.31-0.83), pre-eclampsia (aOR 0.55; 95% CI 0.36-0.85), and delivery at <34 weeks (aOR 0.53; 95% CI 0.29-0.96) or <37 weeks (aOR 0.55; 95% CI 0.35-0.85).

CONCLUSION

These nonrandomised comparisons are subject to residual confounding, but women treated with methyldopa (versus labetalol), particularly those with pre-existing hypertension, may have had better outcomes.

TWEETABLE ABSTRACT

There was no evidence that women treated with methyldopa versus labetalol had worse outcomes.

Less-tight versus tight control of hypertension in pregnancy

BACKGROUND

The effects of less-tight versus tight control of hypertension on pregnancy complications are unclear.

METHODS

We performed an open, international, multicenter trial involving women at 14 weeks 0 days to 33 weeks 6 days of gestation who had nonproteinuric preexisting or gestational hypertension, office diastolic blood pressure of 90 to 105 mm Hg (or 85 to 105 mm Hg if the woman was taking antihypertensive medications), and a live fetus. Women were randomly assigned to less-tight control (target diastolic blood pressure, 100 mm Hg) or tight control (target diastolic blood pressure, 85 mm Hg). The composite primary outcome was pregnancy loss or high-level neonatal care for more than 48 hours during the first 28 postnatal days. The secondary outcome was serious maternal complications occurring up to 6 weeks post partum or until hospital discharge, whichever was later.

RESULTS

Included in the analysis were 987 women; 74.6% had preexisting hypertension. The primary-outcome rates were similar among 493 women assigned to less-tight control and 488 women assigned to tight control (31.4% and 30.7%, respectively; adjusted odds ratio, 1.02; 95% confidence interval [CI], 0.77 to 1.35), as were the rates of serious maternal complications (3.7% and 2.0%, respectively; adjusted odds ratio, 1.74; 95% CI, 0.79 to 3.84), despite a mean diastolic blood pressure that was higher in the less-tight-control group by 4.6 mm Hg (95% CI, 3.7 to 5.4). Severe hypertension (≥160/110 mm Hg) developed in 40.6% of the women in the less-tight-control group and 27.5% of the women in the tight-control group (P<0.001).

CONCLUSIONS

We found no significant between-group differences in the risk of pregnancy loss, high-level neonatal care, or overall maternal complications, although less-tight control was associated with a significantly higher frequency of severe maternal hypertension. (Funded by the Canadian Institutes of Health Research; CHIPS Current Controlled Trials number, ISRCTN71416914; ClinicalTrials.gov number, NCT01192412.).

Essential role for the SLK protein kinase in embryogenesis and placental tissue development

BACKGROUND

Over the past decade, the Ste20-like kinase SLK, has been implicated in several signaling processes. SLK repression has been shown to impair cell cycle kinetics and inhibit FAK-mediated cell migration. Here, using a gene trapped allele, we have generated mice expressing a truncated form of the SLK kinase.

RESULTS

Our results show that an SLK-LacZ fusion protein is expressed in embryonic stem cells and in embryos throughout development. We find that the SLK-LacZ fusion protein is less efficient at phosphorylating substrates resulting in reduced cell proliferation within the embryos and angiogenic defects in the placentae of the homozygous mutant animals at embryonic day (E) 12.5. This results in marked developmental defects and apoptotic lesions in the embryos by E14.5.

CONCLUSIONS

Homozygotes expressing the SLK-LacZ fusion protein present with an embryonic lethal phenotype occurring between E12.5 and E14.5. Overall, we demonstrate a requirement for SLK kinase activity in the developing embryo and placenta.

Uterine Spiral Artery Remodeling: The Role of Uterine Natural Killer Cells and Extravillous Trophoblasts in Normal and High-Risk Human Pregnancies

The process of uterine spiral artery remodeling in the first trimester of human pregnancy is an essential part of establishing adequate blood perfusion of the placenta that will allow optimal nutrient/waste exchange to meet fetal demands during later development. Key regulators of spiral artery remodeling are the uterine natural killer cells and the invasive extravillous trophoblasts. The functions of these cells as well as regulation of their activation states and temporal regulation of their localization within the uterine tissue are beginning to be known. In this review, we discuss the roles of these two cell lineages in arterial remodeling events, their interaction/influence on one another and the outcomes of altered temporal, and spatial regulation of these cells in pregnancy complications.

Immunization in pregnancy

OBJECTIVE

To review the evidence and provide recommendations on immunization in pregnancy.

OUTCOMES

Outcomes evaluated include effectiveness of immunization, risks and benefits for mother and fetus.

EVIDENCE

The Medline and Cochrane databases were searched for articles published up to June 2008 on the topic of immunization in pregnancy.

VALUES

The evidence obtained was reviewed and evaluated by the Infectious Diseases Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC) under the leadership of the principal authors, and recommendations were made according to guidelines developed by the Canadian Task Force on Preventive Health Care.

BENEFITS, HARMS, AND COSTS

Implementation of the recommendations in this guideline should result in more appropriate immunization of pregnant and breastfeeding women, decreased risk of contraindicated immunization, and better disease prevention.

RECOMMENDATIONS

The quality of evidence reported in this document has been assessed using the evaluation of evidence criteria in the Report of the Canadian Task Force on Preventive Health Care (Table 1). (1) All women of childbearing age should be evaluated for the possibility of pregnancy before immunization. (III-A). (2) Health care providers should obtain a relevant immunization history from all women accessing prenatal care. (III-A). (3) In general, live and/or live-attenuated virus vaccines should not be administered during pregnancy, as there is a, largely theoretical, risk to the fetus. (II-3B). (4) Women who have inadvertently received immunization with live or live-attenuated vaccines during pregnancy should not be counselled to terminate the pregnancy because of a teratogenic risk. (II-2A). (5) Non-pregnant women immunized with a live or live-attenuated vaccine should be counselled to delay pregnancy for at least four weeks. (III-B). (6) Inactivated viral vaccines, bacterial vaccines, and toxoids can be used safely in pregnancy. (II-1A). (7) Women who are breastfeeding can still be immunized (passive-active immunization, live or killed vaccines). (II-1A) (8) Pregnant women should be offered the influenza vaccine (including H1N1 vaccine, when it is available) when they are pregnant during the influenza season. (II-1A). (9) Pregnant women with suspected or documented H1N1 infection should be treated with oseltamivir (Tamiflu, 75 mg twice daily for 5 days) within 48 hours of onset of symptoms. (III-B).

Maternal-fetal nutrient transport in pregnancy pathologies: the role of the placenta

Appropriate in utero growth is essential for offspring development and is a critical contributor to long-term health. Fetal growth is largely dictated by the availability of nutrients in maternal circulation and the ability of these nutrients to be transported into fetal circulation via the placenta. Substrate flux across placental gradients is dependent on the accessibility and activity of nutrient-specific transporters. Changes in the expression and activity of these transporters is implicated in cases of restricted and excessive fetal growth, and may represent a control mechanism by which fetal growth rate attempts to match availability of nutrients in maternal circulation. This review provides an overview of placenta nutrient transport with an emphasis on macro-nutrient transporters. It highlights the changes in expression and activity of these transporters associated with common pregnancy pathologies, including intrauterine growth restriction, macrosomia, diabetes and obesity, as well as the potential impact of maternal diet. Molecular signaling pathways linking maternal nutrient availability and placenta nutrient transport are discussed. How sexual dimorphism affects fetal growth strategies and the placenta’s response to an altered intrauterine environment is considered. Further knowledge in this area may be the first step in the development of targeted interventions to help optimize fetal growth.

Obesity Prevention from Conception: A Workshop to Guide the Development of a Pan-Canadian Trial Targeting the Gestational Period

This report summarizes a meeting, Obesity Prevention from Conception, held in Ottawa in 2012. This planning workshop was funded by the Canadian Institutes of Health Research (CIHR) to bring together researchers with expertise in the area of maternal obesity (OB) and weight gain in pregnancy and pregnancy-related disease to attend a one-day workshop and symposium to discuss the development of a cross-Canada lifestyle intervention trial for targeting pregnant women. This future intervention will aim to reduce downstream OB in children through encouraging appropriate weight gain during the mother’s pregnancy. The workshop served to (i) inform the development of a lifestyle intervention for women with a high pre-pregnancy body mass index (BMI), (ii) identify site investigators across Canada, and (iii) guide the development of a grant proposal focusing on the health of mom and baby. A brief summary of the presentations as well as the focus groups is presented for use in planning future research.

First-trimester levels of pregnancy-associated plasma protein A2 (PAPP-A2) in the maternal circulation are elevated in pregnancies that subsequently develop preeclampsia

Recent studies have consistently found pregnancy-associated plasma protein A2 (PAPP-A2) to be upregulated in preeclamptic placentae at term. We tested whether first-trimester circulating PAPP-A2 levels differed between complicated and uncomplicated pregnancies. We measured maternal PAPP-A2 levels at 10 to 14 weeks of gestational age in 17 pregnancies resulting in small-for-gestational-age (SGA) infants, 6 which developed preeclampsia (PE), 1 which developed PE and resulted in an SGA infant, and 37 gestational age-matched controls. The concentration of the PAPP-A2 isoform corresponding to the full-length protein was significantly higher in pregnancies that developed PE (35 ng/mL) compared with those that did not (23 ng/mL; P < .044). In contrast, we found no difference in PAPP-A2 levels between pregnancies that did or did not result in an SGA infant. The upregulation of PAPP-A2 that has previously been observed in PE at term appears to begin early in pregnancy, well before the symptoms develop.

Excessive gestational weight gain and obesity contribute to altered expression of maternal insulin-like growth factor binding protein-3

BACKGROUND

Excessive gestational weight gain (GWG) increases risk of large for gestational age neonates and subsequent tracking of excess weight throughout the life course for both mother and child. Although the physiological mechanisms underlying these associations are incomplete, the insulin-like growth factor (IGF) axis has garnered attention for its role in fetal growth and development. Our purpose was to characterize the IGF axis protein expression patterns in mother-infant dyads in respect of excessive GWG.

METHODS

WE OBTAINED FASTING SERUM SAMPLES AND CORRESPONDING CORD BLOOD FROM EIGHT CONTROLS (ADHERE GROUP: ie, those who gained in accordance with 2009 Institute of Medicine GWG recommendations) and 13 exceeders (EXCEED group: ie, those who exceeded Institute of Medicine GWG recommendations). At study completion, we examined protein expression of IGF-I, IGF-II, IGF binding protein (IGFBP)-1, IGFBP-3, IGFBP-4, and hormone concentrations in both maternal and cord blood.

RESULTS

Between-group comparisons were made and revealed elevated maternal leptin (P ≤ 0.05) concentrations in gravidas who exceeded recommendations. There was a significantly higher number of obese women in the EXCEED group (P < 0.05). After adjustment, maternal leptin levels were positively correlated with maternal homeostasis model of assessment for insulin resistance score and excessive GWG (P ≤ 0.01). However, serum IGFBP-3 expression in the EXCEED mothers was greater than that in the ADHERE group (P ≤ 0.05).

CONCLUSION

These findings provide preliminary evidence suggesting that small deviations in IGFBP-regulated IGF bioavailability arising from excessive GWG/positive energy balance may affect adipocyte differentiation through subclinical insulin resistance.

Therapeutic potential of amniotic fluid-derived cells for treating the injured nervous system

There is a need for improved therapy for acquired brain injury, which has proven resistant to treatment by numerous drugs in clinical trials and continues to represent one of the leading causes of disability worldwide. Research into cell-based therapies for the treatment of brain injury is growing rapidly, but the ideal cell source has yet to be determined. Subpopulations of cells found in amniotic fluid, which is readily obtained during routine amniocentesis, can be easily expanded in culture, have multipotent differentiation capacity, are non-tumourigenic, and avoid the ethical complications associated with embryonic stem cells, making them a promising cell source for therapeutic purposes. Beneficial effects of amniotic fluid cell transplantation have been reported in various models of nervous system injury. However, evidence that amniotic fluid cells can differentiate into mature, functional neurons in vivo and incorporate into the existing circuitry to replace lost or damaged neurons is lacking. The mechanisms by which amniotic fluid cells improve outcomes after experimental nervous system injury remain unclear. However, studies reporting the expression and release of neurotrophic, angiogenic, and immunomodulatory factors by amniotic fluid cells suggest they may provide neuroprotection and (or) stimulate endogenous repair and remodelling processes in the injured nervous system. In this paper, we address recent research related to the neuronal differentiation of amniotic fluid-derived cells, the therapeutic efficacy of these cells in animal models of nervous system injury, and the possible mechanisms mediating the positive outcomes achieved by amniotic fluid cell transplantation.

Applications of amniotic membrane and fluid in stem cell biology and regenerative medicine

The amniotic membrane (AM) and amniotic fluid (AF) have a long history of use in surgical and prenatal diagnostic applications, respectively. In addition, the discovery of cell populations in AM and AF which are widely accessible, nontumorigenic and capable of differentiating into a variety of cell types has stimulated a flurry of research aimed at characterizing the cells and evaluating their potential utility in regenerative medicine. While a major focus of research has been the use of amniotic membrane and fluid in tissue engineering and cell replacement, AM- and AF-derived cells may also have capabilities in protecting and stimulating the repair of injured tissues via paracrine actions, and acting as vectors for biodelivery of exogenous factors to treat injury and diseases. Much progress has been made since the discovery of AM and AF cells with stem cell characteristics nearly a decade ago, but there remain a number of problematic issues stemming from the inherent heterogeneity of these cells as well as inconsistencies in isolation and culturing methods which must be addressed to advance the field towards the development of cell-based therapies. Here, we provide an overview of the recent progress and future perspectives in the use of AM- and AF-derived cells for therapeutic applications.

Characterization of the insulin-like growth factor axis in term pregnancies complicated by maternal obesity

STUDY QUESTION

Does maternal obesity affect insulin-like growth factor (IGF) axis protein expression patterns in maternal and cord blood?

SUMMARY ANSWER

Maternal obesity attenuates cord blood expression of IGF-binding protein (IGFBP)-4.

WHAT IS KNOWN AND WHAT THIS PAPER ADDS

The IGF axis plays a critical role in fetal growth and development. Maternal obesity compromises IGF axis protein expression in fetal circulation, which is consistent with the findings of epidemiological studies suggesting that maternal obesity has an independent effect on fetal growth signals during in utero development.

STUDY DESIGN

This cross-sectional case-control study involved 12 lean [body mass index (BMI) 18.5-24.9 kg/m2] and 12 obese (BMI≥30 kg/m2) women and their neonates at term. At the completion of the study, IGF axis protein expression and hormone concentrations in both maternal and cord blood were examined.

PARTICIPANTS AND SETTING

We obtained fasting serum samples from cases and controls matched for age, gestation, mode of delivery, parity and glucose tolerance prior to and immediately following elective caesarean section. The corresponding umbilical cord blood was also collected at birth.

MAIN RESULTS AND THE ROLE OF CHANCE

Between-group comparisons revealed elevated maternal insulin (P=0.03) and leptin (P<0.01) concentrations in obese gravidas. After adjustment, the maternal homeostasis model of assessment-insulin resistance (HOMA-IR) score was positively correlated with both maternal BMI and leptin levels (P<0.01). Umbilical cord blood levels of IGFBP-3 showed an inverse trend to maternal HOMA-IR (P=0.03) but were directly related to the fetal-placental weight ratio (P<0.01). In cord serum from obese mothers, IGFBP-4 expression was attenuated compared with the controls (P<0.05).

LIMITATIONS

The limitations of our study include the cross-sectional design and relatively small sample size.

WIDER IMPLICATIONS

Our results provide preliminary evidence for the applicability of our findings to other ethnic groups when pregnancy is complicated by obesity.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the University of Ottawa, Faculty of Health Sciences/Children's Hospital of Eastern Ontario Research Partnership Grant awarded to K.B.A. and Z.M.F. The authors have no conflicts of interest to declare.

Characterization and role of NUMB in the human extravillous trophopblast

NUMB is a multifunctional protein involved in asymmetric cell differentiation, proliferation and maintenance. Four mammalian NUMB isoforms have been identified, which utilize the phosphotyrosine binding (PTB) domain and the proline rich region (PRR) domain to regulate cell growth and differentiation in the developing nervous system. The observation that a decrease in spongiotrophoblast number and thickness of placentae of null (Numb(-/-)) mouse embryos, which died at E10.5, suggests NUMB may play a role in placental development. In this study, we demonstrated for the first time, that NUMB isoforms 1, 2, 3, and 4 are present in the human placenta and the human extravillous trophoblast (EVT) cell line HTR8/SVneo. We report three novel isoforms, NUMB 7, 8, and 9, identified by cloning of RT-PCR products and sequencing. Corresponding sequences of novel isoforms were submitted to genebank (accession numbers for each new isoform: NUMB 7- EU265736, NUMB 8- EU265737 and NUMB 9-EU265738). Western blot analysis confirmed the presence of all NUMB isofoms in human placental samples in all trimesters and in EVT cells. NUMB immunosignals were extensively localized in human extravillous trophoblasts and decidual cells at the maternal-fetal interface. NUMB 8 appeared to be the predominant isoform in placental villi. Furthermore, cell migration studies revealed NUMB isoform 1 to be involved in EVT cell migration and NUMB isoforms 2 and 4 to induce EVT apoptosis.

Novel RBPJ transcripts identified in human amniotic fluid cells

The NOTCH signaling pathway plays important roles in stem cell maintenance, cell-fate determination and differentiation during development. Following ligand binding, the cleaved NOTCH intracellular domain (NICD) interacts directly with the recombinant signal binding protein for immunoglobulin kappa J region (RBPJ) transcription factor and the resulting complex targets gene expression in the nucleus. To date, four human RBPJ isoforms have been described in Entrez Gene, varying in the first 5'coding exons. Using an improved protocol, we were able to further identify all four known and five novel RBPJ transcript variants in human amniotic fluid (AF) cells, a cell type known for its stem cell characteristics. In addition, we used human embryonal carcinoma (EC) NTera2/D1 (NT2) cells and NT2-derived neuron and astrocytes to compare the expression pattern of RBPJ transcripts. Further examination of RBPJ transcripts showed that the novel splice variants contain open reading frames in-frame with the known isoforms, suggesting that they can putatively generate similar function proteins. All known and novel RBPJ transcripts contain the putative nuclear localization signal (NLS), an important component of RBPJ-mediated gene regulation.

Prediction of adverse maternal outcomes in pre-eclampsia: development and validation of the fullPIERS model

BACKGROUND

Pre-eclampsia is a leading cause of maternal deaths. These deaths mainly result from eclampsia, uncontrolled hypertension, or systemic inflammation. We developed and validated the fullPIERS model with the aim of identifying the risk of fatal or life-threatening complications in women with pre-eclampsia within 48 h of hospital admission for the disorder.

METHODS

We developed and internally validated the fullPIERS model in a prospective, multicentre study in women who were admitted to tertiary obstetric centres with pre-eclampsia or who developed pre-eclampsia after admission. The outcome of interest was maternal mortality or other serious complications of pre-eclampsia. Routinely reported and informative variables were included in a stepwise backward elimination regression model to predict the adverse maternal outcome. We assessed performance using the area under the curve (AUC) of the receiver operating characteristic (ROC). Standard bootstrapping techniques were used to assess potential overfitting.

FINDINGS

261 of 2023 women with pre-eclampsia had adverse outcomes at any time after hospital admission (106 [5%] within 48 h of admission). Predictors of adverse maternal outcome included gestational age, chest pain or dyspnoea, oxygen saturation, platelet count, and creatinine and aspartate transaminase concentrations. The fullPIERS model predicted adverse maternal outcomes within 48 h of study eligibility (AUC ROC 0·88, 95% CI 0·84-0·92). There was no significant overfitting. fullPIERS performed well (AUC ROC >0·7) up to 7 days after eligibility.

INTERPRETATION

The fullPIERS model identifies women at increased risk of adverse outcomes up to 7 days before complications arise and can thereby modify direct patient care (eg, timing of delivery, place of care), improve the design of clinical trials, and inform biomedical investigations related to pre-eclampsia.

FUNDING

Canadian Institutes of Health Research; UNDP/UNFPA/WHO/World Bank Special Programme of Research, Development, and Research Training in Human Reproduction; Preeclampsia Foundation; International Federation of Obstetricians and Gynecologists; Michael Smith Foundation for Health Research; and Child and Family Research Institute.

Altered levels of insulin-like growth factor binding protein proteases in preeclampsia and intrauterine growth restriction

Intrauterine growth restriction (IUGR) and preeclampsia (PE) are leading causes of perinatal and maternal morbidity and mortality. Many studies have found association between low levels of insulin-like growth factor binding protein (IGFBP) proteases in the first trimester maternal circulation and the risk of subsequent development of PE and/or IUGR. These results are generally interpreted to reflect decreased production of the proteases by the placenta, leading to reduced proteolysis of IGFBPs and lower free levels of insulin-like growth factor (IGF), resulting in diminished feto-placental development. However, the association between low circulating levels of placental proteins early in pregnancy and the subsequent development of IUGR and/or PE could be due to low exchange in the placenta and not due to reduced production. In contrast, late in pregnancy, the circulating levels of these proteins and their expression in the placenta are often elevated in PE, which may reflect upregulation to compensate for abnormal placental development, that is an adaptive mechanism to increase IGFBP proteolysis, increase local IGF levels and promote feto-placental growth. Further research into the biological mechanisms underlying these associations will aid the identification of high-risk pregnancies and the development of therapeutic targets for diseases for which there are presently no preventative measures.

Antibioprophylaxie dans le cadre d'interventions obstétricales

Objectif

Analyser les résultats et formuler des recommandations sur le recours à l'antibioprophylaxie dans le cadre d'interventions obstétricales.

Issues

Parmi les issues évaluées, on trouve la nécessité et l'efficacité du recours à des antibiotiques aux fins de la prévention des infections dans le cadre d'interventions obstétricales.

Résultats

La littérature publiée a été récupérée par l'intermédiaire de recherches menées dans Medline et The Cochrane Library au moyen de la rubrique « antibioprophylaxie dans le cadre d'interventions obstétricales ». Les résultats ont été restreints aux analyses systématiques, aux essais comparatifs randomisés / essais cliniques comparatifs et aux études observationnelles. Les recherches ont été mises à jour de façon régulière et les articles publiés entre janvier 1978 et juin 2009 ont été incorporés à la directive clinique. Les lignes directrices actuellement publiées par le American College of Obstetrics and Gynecology ont également été incorporées à la directive clinique. La littérature grise (non publiée) a été identifiée par l'intermédiaire de recherches menées dans les sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, dans des registres d'essais cliniques et auprès de sociétés de spécialité médicale nationales et internationales.

Valeurs

Les résultats obtenus ont été analysés et évalués par le comité sur les maladies infectieuses de la Société des obstétriciens et gynécologues du Canada sous la gouverne des auteures principales, et les recommandations ont été formulées conformément aux lignes directrices élaborées par le Groupe d'étude canadien sur les soins de santé préventifs (Tableau 1).

Avantages, désavantages et coûts

La mise en œuvre de la présente directive clinique devrait réduire les coûts et les torts attribuables à l’administration d’antibiotiques lorsque celle-ci ne s’avère pas requise, ainsi que les torts attribuables à la non-administration d’antibiotiques lorsque ceux-ci pourraient s’avérer bénéfiques.

Déclarations sommaires

1.

Les données disponibles ne soutiennent pas le recours à l'antibioprophylaxie en vue d'atténuer la morbidité infectieuse à la suite d'un accouchement vaginal opératoire. (II-1)

2.

Nous ne disposons pas de données suffisantes pour soutenir ou déconseiller le recours à l'antibioprophylaxie en vue d'atténuer la morbidité infectieuse dans les cas de retrait manuel du placenta. (III)

3.

Nous ne disposons pas de données suffisantes pour soutenir ou déconseiller le recours à l'antibioprophylaxie au moment de la dilatation-curetage postpartum visant des produits de conception en rétention. (III)

4.

Les données disponibles ne soutiennent pas le recours à l'antibioprophylaxie en vue d'atténuer la morbidité infectieuse à la suite d'un cerclage planifié ou d'urgence. (II-3)

Recommandations

1.

Toutes les femmes qui subissent une césarienne planifiée ou d'urgence devraient se voir administrer une antibioprophylaxie. (I-A)

2.

Une dose unique d'une céphalosporine de première génération devrait constituer l'antibiotique à privilégier pour ce qui est des césariennes. Lorsque la patiente présente une allergie à la pénicilline, on peut avoir recours à la clindamycine ou à l'érythromycine. (I-A)

3.

Dans le cas de la césarienne, l'antibioprophylaxie devrait être administrée de 15 à 60 minutes avant l'incision de la peau. Aucune dose additionnelle n'est recommandée. (I-A)

4.

Lorsqu'une intervention à abdomen ouvert est de longue durée (>3 heures) ou que la perte sanguine estimée est supérieure à 1 500 ml, une dose additionnelle d'antibiotique prophylactique peut être administrée de 3 à 4 heures à la suite de la dose initiale. (III-L)

5.

L'administration d'une antibioprophylaxie peut être envisagée pour atténuer la morbidité infectieuse associée à la réparation d'une lésion périnéale du troisième ou du quatrième degré. (I-B)

6.

Chez les patientes massivement obèses (IMC > 35), il est possible d'envisager le doublement de la dose d'antibiotiques. (III-B)

7.

L’administration d’antibiotiques aux seules fins de prévenir l’endocardite ne devrait pas être mise en œuvre chez les patientes qui doivent subir une intervention obstétricale, quelle qu’en soit la nature. (III-E)

Mature IGF-II prevents the formation of "big" IGF-II/IGFBP-2 complex in the human circulation

IGF-II plays an important role in physiological and pathological processes involved in growth and metabolism. Despite the fact that "big" IGF-IIs, IGF-II(1-87) and IGF-II(1-104), have been identified in the circulation for decades in addition to "mature" IGF-II, the biological properties of these "big" IGF-IIs and the mechanisms regulating their bioavailability have not been fully elucidated. In this study we demonstrated that IGF-II (1-87), as an abundant "big" IGF-II form, exists at a molar ratio of 0.24 (CI 0.13-0.62) with respect to mature IGF-II in the normal human circulation. Mature and "big" IGF-II can equally form complexes with IGFBP-2 and IGFBP-3 in vitro, resulting in the inhibition of IGF-II's biological function. However, under physiological conditions which entails the presence of both "big" and mature IGF-II, "big" IGF-IIs preferably formed complexes with IGFBP-3 but not IGFBP-2, unlike mature IGF-II which was equally associated with both IGFBP-3 and IGFBP-2. "Big" IGF-II binding to IGFBP-2 was only evident when the "big"/mature IGF-II ratio approached 1 or higher. We concluded that mature IGF-II prevents the formation of "big" IGF-II/IGFBP-2 complex in the circulation of healthy human controls. This finding suggests the presence of previously unknown mechanisms in the regulation of IGF-II bioavailability. Elevation of the ratio of "big" to mature IGF-II in the circulation may result in altered bioavailability of "big" IGF-IIs. This mechanism is relevant in pathological conditions such as Non-Islet Cell Tumor-induced Hypoglycemia (NICTH) and Hepatitis C-associated Osteosclerosis (HCAO), in which "big" IGF-II(1-87) and IGF-II(1-104) are significantly elevated.

Expression of pregnancy-associated plasma protein A2 during pregnancy in human and mouse

Pregnancy-associated plasma protein-A and -A2 (PAPPA and PAPPA2) are proteases that cleave IGF binding proteins (IGFBPs) and thereby increase the bioavailability of growth factors. PAPPA has long been recognized as a marker of fetal genetic disorders and adverse pregnancy outcomes. In contrast, although PAPPA2 is also highly expressed in human placenta, its physiological importance is not clear. To establish whether mice will be a useful model for the study of PAPPA2, we compared the patterns of expression of PAPPA2 in the placentae of mouse and human. We show, for the first time, that Pappa2 is highly expressed in mouse placenta, as is the case in humans. Specifically, it is expressed at the interface of the maternal and fetal layers of the mouse placenta at all gestational stages studied (10.5-16.5 days post coitum). Similarly, PAPPA2 is expressed in the syncytiotrophoblast layer of human placental villi and is also detected in some invasive extravillous trophoblasts in the first trimester. These results are consistent with a model whereby PAPPA2 cleaves IGFBPs produced in the maternal decidua to promote feto-placental growth, and indicate that this protein may play analogous roles in human and mouse placenta. PAPPA2 protein is detectable in the circulation of pregnant mice and humans during the first trimester and at term, raising the possibility that PAPPA2 may be a useful biomarker of placental dysfunction. Pappa2 expression also shows specific localization within the mouse embryo and therefore may play roles in fetal development, independent of its action in the placenta.

A Survey of Canadian Practitioners Regarding Diagnosis and Evaluation of the Hypertensive Disorders of Pregnancy

BACKGROUND

How Canadian practitioners are diagnosing and managing the hypertensive disorders of pregnancy (HDP), particularly in relation to the 1997 recommendations published by the Canadian Hypertension Society (CHS), is not known.

METHODS

A survey, with French and English versions (and covering diagnosis, evaluation, and management of pregnancy hypertension), was mailed to all members of the Society of Obstetricians and Gynaecologists of Canada (SOGC) (N = 1757, including obstetricians, family doctors practicing obstetrics, and midwives). Additionally, internists [i.e., all nephrologists (N = 191) and a random sample of 25% of general internists (N = 450)] registered with the Royal College of Physicians and Surgeons of Canada were sampled. The survey was distributed in two mailings and one reminder card. Data were entered into Microsoft Access, and Graph Pad Prism used to summarize responses [N (%)]. Differences in practice between specialties were examined, with a Bonferonni correction used to calculate a significant p value based on the number of comparisons and alpha of 0.05.

RESULTS

Respondents numbered 1187 (49.5%), with 466 not informative for the purpose of the study (due to retirement, or practices that do not include pregnant women with hypertension). The final analysis included 721 completed surveys. Most (609, 84.5% of) respondents take blood pressure (BP) with women in the sitting position, and use a mercury sphygmomanometer (79%) and the 5th Korotkoff (61%) sound to designate diastolic BP (dBP). To monitor pregnancies complicated by preeclampsia, most clinicians use the proposed laboratory tests of maternal well-being (usually at least once/week), fetal well-being [nonstress test (NST, at least once/week), and ultrasonographic studies (once weekly to every two weeks)]. There is general agreement that women with preeclampsia should be delivered for uncontrolled hypertension, end-organ dysfunction, or fetal compromise (nonreassuring NST, severe oligohydramnios, biophysical profile < 4, estimated fetal weight < 5th centile, and reversed end-diastolic flow by umbilical artery Doppler velocimetry). Less consensus was seen for delivery for preeclampsia at > 34 weeks, mild asymptomatic HELLP syndrome, hyperreflexia, and absent end-diastolic flow by umbilical artery Doppler velocimetry.

INTERPRETATION

This survey has clarified the current state of practice with respect to the diagnosis and evaluation of women with all types of HDP. In particular, we have identified areas of potential variability in BP measurement, and provided data on the feasibility of enrolling women with sub types of preeclampsia into intervention studies aimed at prolonging pregnancy.

Effect of nicotine exposure during pregnancy and lactation on maternal, fetal, and postnatal rat IGF-II profile

Smoking during pregnancy has been shown to result in an increased risk of low birth weight. However, the mechanisms underlying this association are poorly understood. The insulin-like growth factor (IGF) system plays a critical role in the regulation of feto-placental growth and development, and abnormal processing of proIGF-II may alter its biological function. Our goal was to investigate the effects of exposure to nicotine on maternal, fetal, and neonatal IGF-II processing. Nulliparous female Wistar rats were randomly assigned to receive saline (vehicle) or nicotine bitartrate (1 mg x kg(-1) x d(- 1)). After mating, dams were euthanized at embryonic days 15, 18, and 21, and fetal body weight was recorded. Serum (fetal and maternal) was collected for determination of the IGF-II profile by Western blot analysis. Nicotine exposure prevented the decrease in maternal IGF-II processing seen in controls with advancing gestation. However, there was no influence of nicotine on fetal levels of IGF-II. Postnatally (postnatal day [PND] 21), pups exposed to nicotine in utero had decreased levels of big IGF-II. Our results show, for the first time, that nicotine exposure prevents the decrease of IGF-II processing in the maternal compartment. This may represent a compensatory mechanism allowing the mother to counteract the negative influence of nicotine on fetal growth and development. Our postnatal findings of suppressed IGF-II may help explain some of the long-term health complications seen in individuals exposed to smoking in utero.