Lise Goulet

Stress Pathways to Spontaneous Preterm Birth: The Role of Stressors, Psychological Distress, and Stress Hormones

The authors investigated a large number of stressors and measures of psychological distress in a multicenter, prospective cohort study of spontaneous preterm birth among 5,337 Montreal (Canada)-area women who delivered from October 1999 to April 2004. In addition, a nested case-control analysis (207 cases, 444 controls) was used to explore potential biologic pathways by analyzing maternal plasma corticotrophin-releasing hormone (CRH), placental histopathology, and (in a subset) maternal hair cortisol. Among the large number of stress and distress measures studied, only pregnancy-related anxiety was consistently and independently associated with spontaneous preterm birth (for values above the median, adjusted odds ratio = 1.8 (95% confidence interval: 1.3, 2.4)), with a dose-response relation across quartiles. The maternal plasma CRH concentration was significantly higher in cases than in controls in crude analyses but not after adjustment (for concentrations above the median, adjusted odds ratio = 1.1 (95% confidence interval: 0.8, 1.6)). In the subgroup (n = 117) of participants with a sufficient maternal hair sample, hair cortisol was positively associated with gestational age. Neither maternal plasma CRH, hair cortisol, nor placental histopathologic features of infection/inflammation, infarction, or maternal vasculopathy were significantly associated with pregnancy-related anxiety or any other stress or distress measure. The biologic pathways underlying stress-induced preterm birth remain poorly understood.

Incidence of cancer among persons living near a municipal solid waste landfill site in Montreal, Québec.

The Miron Quarry municipal solid waste landfill site in Montreal, Québec, generates copious quantities of methane and other gases, including a rich mixture of volatile organic compounds, some of which are recognized or suspected human carcinogens. The site is the third largest in North America and is located in the center of a densely populated area. Using data from the Québec Tumour Registry, we conducted Poisson regression analyses to evaluate whether cancer incidence among persons who lived near the site was higher than expected. Potential exposure to ambient air pollutants from the site was defined in terms of a set of geographic exposure zones proximal to the site. A set of reference areas distal from the site was selected to be similar to these exposure zones with respect to several key sociodemographic factors. Risk ratios (RRs) were adjusted for age and calendar year. Among men living in the exposure zone closest to the site, elevated risks were observed for cancers of the stomach (RR = 1.3, 95% confidence interval [95% CI] = 1.0-1.5); liver and intrahepatic bile ducts (RR = 1.3, 95% CI = 0.9-1.8); and trachea, bronchus, and lung (RR = 1.1, 95% CI = 1.0-1.2). Among women, rates of stomach cancer (RR = 1.2; 95% CI = 0.9-1.5) and cervix uteri cancer were elevated (RR = 1.2, 95% CI = 1.0-1.5), but breast cancer incidence was less than expected (RR = 0.9, 95% CI = 0.9-1.0). Prostate cancer was also elevated in one of the proximal exposure subzones (RR = 1.2, 95% CI = 1.0-1.4). Further studies at this and at other landfill sites are needed to confirm or refute these observations.

Facilitators and barriers in the humanization of childbirth practice in Japan

BackgroundHumanizing birth means considering womens values, beliefs, and feelings and respecting their dignity and autonomy during the birthing process. Reducing over-medicalized childbirths, empowering women and the use of evidence-based maternity practice are strategies that promote humanized birth. Nevertheless, the territory of birth and its socio-cultural values and beliefs concerning child bearing can deeply affect birthing practices. The present study aims to explore the Japanese child birthing experience in different birth settings where the humanization of childbirth has been indentified among the priority goals of the institutions concerned, and also to explore the obstacles and facilitators encountered in the practice of humanized birth in those centres.MethodsA qualitative field research design was used in this study. Forty four individuals and nine institutions were recruited. Data was collected through observation, field notes, focus groups, informal and semi-structured interviews. A qualitative content analysis was performed.ResultsAll the settings had implemented strategies aimed at reducing caesarean sections, and keeping childbirth as natural as possible. The barriers and facilitators encountered in the practice of humanized birth were categorized into four main groups: rules and strategies, physical structure, contingency factors, and individual factors. The most important barriers identified in humanized birth care were the institutional rules and strategies that restricted the presence of a birth companion. The main facilitators were womens own cultural values and beliefs in a natural birth, and institutional strategies designed to prevent unnecessary medical interventions.ConclusionsThe Japanese birthing institutions which have identified as part of their mission to instate humanized birth have, as a whole, been successful in improving care. However, barriers remain to achieving the ultimate goal. Importantly, the cultural values and beliefs of Japanese women regarding natural birth is an important factor promoting the humanization of childbirth in Japan.

Inherited thrombophilia and preeclampsia within a multicenter cohort: the Montreal Preeclampsia Study.

OBJECTIVE We sought to evaluate the association between inherited thrombophilia and preeclampsia. STUDY DESIGN From a multicenter cohort of 5337 pregnant women, we prospectively identified 113 women who developed preeclampsia and selected 443 control subjects who did not have preeclampsia or nonproteinuric gestational hypertension. Blood samples were tested for DNA polymorphisms affecting thrombophilia (factor V Leiden mutation, prothrombin G20210A mutation, methylenetetrahydrofolate reductase C677T polymorphism), homocysteine, and folate levels, and placentae underwent pathological evaluation. RESULTS Thrombophilia was present in 14% of patients and 21% of control subjects (adjusted logistic regression odds ratio, 0.6; 95% confidence interval, 0.3-1.3). Placental underperfusion was present in 63% of patients vs 46% of control subjects (P < .001) and was more frequent in women with folate levels in the lowest quartile (P = .04), but was not associated with thrombophilia. CONCLUSION We did not find evidence to support an association between inherited thrombophilia and increased risk of preeclampsia. Placental underperfusion is associated with preeclampsia, but this does not appear to be consequent to thrombophilia.

Vasculopathic and thrombophilic risk factors for spontaneous preterm birth

BACKGROUND Mothers who give birth to preterm infants are at increased risk of mortality from coronary heart disease and stroke, but the biological pathways underlying these associations have not been explored. METHODS We carried out a case-control study nested in a large (n = 5337) prospective, multicentre cohort. All cohort women had an interview, examination and venipuncture at 24-26 weeks. Frozen plasma samples in spontaneous preterm births (n = 207) and 444 term controls were analysed for plasma homocysteine, folate, cholesterol (total, low-density lipoprotein and high-density lipoprotein) and thrombin-antithrombin (TAT) complexes. DNA was extracted and analysed for seven gene polymorphisms involved in thrombophilia or folate or homocysteine metabolism. Fresh placentas were fixed, stained and blindly assessed for histologic evidence of infarction and decidual vasculopathy. RESULTS High (above the median) plasma homocysteine and HDL cholesterol were significantly and independently associated with the risk of spontaneous preterm birth [adjusted odds ratios (OR)s = 1.9 (95% 1.1-3.3) and 0.5 (0.3-0.9), respectively]. A higher proportion of women with high homocysteine concentrations had decidual vasculopathy [(13.0 vs 6.8%; OR = 1.9 (1.1-3.5)], although the positive association between decidual vasculopathy and preterm birth did not achieve statistical significance [OR = 1.5 (0.9-2.7)]. No significant associations were observed with the DNA polymorphisms or with plasma TAT or folate levels. CONCLUSIONS Similar vasculopathic risk factors may underlie preterm birth and adult coronary heart disease and stroke.

Reliability and validity of adapted French Canadian version of Scoliosis Research Society Outcomes Questionnaire (SRS-22) in Quebec.

Study Design. Prospective validation study of a cross-cultural adaptation of the Scoliosis Research Society (SRS) Outcomes Questionnaire. Objective. To provide a French Canadian version of the SRS Outcomes Questionnaire and to empirically test its response in healthy adolescents and adolescent idiopathic scoliosis (AIS) patients in Québec. Summary of Background Data. The SRS Outcomes Questionnaire is widely used for the assessment of health-related quality of life in AIS patients. Methods. French translation and back-translation of the SRS-22 (SRS-22-fv) were done by an expert committee. Its reliability was measured using the coefficient of internal consistency, construct validity with a factorial analysis, concurrent validity by using the short form-12 and discriminant validity using ANOVA and multivariate linear regression, on 145 AIS patients, 44 patients with non clinically significant scoliosis (NCSS), and 64 healthy patients. Results. The SRS-22-fv showed a good global internal consistency (AIS: Cronbach &agr; = 0.86, NCSS: 0.81, and controls: 0.79) and in all of its domains for AIS patients. The factorial structure was coherent with the original questionnaire (47.4% of explained variance). High correlation coefficients were obtained between SRS-22-fv and short form-12 corresponding domains. Boys had higher scores than girls, scores worsened with age, and with increasing body mass index. Mean Total, Pain, Self-image, and Satisfaction scores, were correlated with Cobb angle. Adjusted regression models showed statistically significant differences between the AIS, NCSS, and control groups in the Total, Pain, and Function scores. Conclusion. The SRS-22-fv showed satisfactory reliability, factorial, concurrent, and discriminant validity. This study provides scores in a significant group of healthy adolescents and demonstrates a clear gradient in response between subjects with AIS, NCSS, and controls.

Mid-trimester maternal plasma cytokines and CRP as predictors of spontaneous preterm birth.

Most previous studies of maternal cytokines and preterm birth have analyzed immunologic biomarkers after the onset of labor or membrane rupture; fewer have examined the systemic (blood) immune response prior to labor onset. We carried out a case-control study nested in a large (n=5337) prospective, multi-center cohort. Cohort women had an interview, examination, and venipuncture at 24-26 weeks. Frozen plasma samples in women with spontaneous preterm birth (n=207) and approximately 2 term controls per case (n=444) were analyzed using Luminex multianalyte profiling technology. Fresh placentas were fixed, stained, and blindly assessed for histologic evidence of infection/inflammation, decidual vasculopathy, and infarction, and vaginal swabs were analyzed for bacterial vaginosis and fetal fibronectin concentration. High maternal matrix metalloproteinase-9 (MMP-9) concentration, but none of the other cytokines or C-reactive protein (CRP), was significantly associated with spontaneous preterm birth [adjusted OR=1.7 (1.1-2.4)] and showed a dose-response relation across quartiles. No association was observed, however, between maternal MMP-9 and placental infection/inflammation, bacterial vaginosis, or vaginal fetal fibronectin concentration. Our results require confirmation in future studies but suggest that a systemic immune response implicating MMP-9 may have an etiologic role in spontaneous preterm birth.

Patient characteristics at the initial visit to a scoliosis clinic: a cross-sectional study in a community without school screening.

Study Design. A cross-sectional study was conducted of all patients referred for an initial visit to the orthopedic outpatient clinic of a metropolitan pediatric hospital in Canada for suspected adolescent idiopathic scoliosis (AIS). Objective. To document the appropriateness of current referral patterns for AIS in comparison to those that were prevailing before discontinuation of school screening in Canada. Summary of Background Data. The consequences of the discontinuation of school scoliosis screening programs on the referral patterns of AIS patients remain unknown. Methods. The clinical and radiologic charts of the 636 consecutive patients referred for scoliosis evaluation over a 1-year period were reviewed. Patients were classified according to defined criteria of appropriateness of referral based on skeletal maturity and curve magnitude. Results. Of the 489 suspected cases of AIS, 206 (42%) had no significant deformity (Cobb angle <10°) and could be considered as inappropriate referrals. In subjects with confirmed AIS, 91 patients (32%) were classified as late referrals with regards to brace treatment indications. Conclusions. These findings suggest that current referral mechanisms for AIS are leading to a suboptimal case-mix in orthopedics in terms of appropriateness of referral.

Maternal Stress/Distress, Hormonal Pathways and Spontaneous Preterm Birth

BACKGROUND Although second-trimester blood corticotrophin-releasing hormone (CRH) levels are robustly associated with preterm birth, the findings with respect to cortisol have been inconsistent, as have been those relating stress hormones to measured stressors and maternal distress. METHODS We measured plasma CRH, adrenocorticotrophic hormone (ACTH), cortisol, cortisol-binding globulin, oestradiol and progesterone at 24-26 weeks in a nested case-control study of 206 women who experienced spontaneous preterm birth and 442 term controls. We also related the hormonal levels to measures of environmental stressors, perceived stress and maternal distress (also assessed at 24-26 weeks) and to placental histopathology. RESULTS With the exception of an unexpectedly low oestradiol:progesterone ratio among cases (adjusted odds ratio = 0.5 [95% confidence interval 0.3, 0.8] for ratios above the median in controls), none of the hormonal measures was independently associated with spontaneous preterm birth; placental histopathological evidence of infection/inflammation, infarction or decidual vasculopathy; or measures of maternal stress or distress. CRH levels were positively associated with cortisol, but not with ACTH, whereas ACTH was also positively associated with cortisol. CONCLUSIONS Our findings suggest an intact pituitary-adrenal axis and confirm the positive feedback effect of cortisol on (placental) CRH. Neither of these hormonal pathways, however, was strongly linked to maternal stress/distress or to the risk of spontaneous preterm birth.

Occupational disability related to back pain: application of a theoretical model of work disability using prospective cohorts of manual workers.

BACKGROUND A new model of work disability was developed based on the assumption that four different groups of workers are present at the beginning of a prospective epidemiologic study: one group of workers without back pain, and three groups of workers with back pain and a gradient of work disability. The goal of this research was to verify if these groups comprise workers at different levels of risk of occurrence of complete work disability related to back injury. METHODS Prospective cohorts of manual workers (n=578) were followed for 1 year to document the risk of occurrence of complete disability related to back injury. RESULTS The results showed that the workers who presented with back pain without work disability at the beginning of the study were at less risk compared to all the other workers in the cohort. Moreover, an effect modification was found between the workers who initially presented with back pain without work disability and a past history of compensation for back injury, adding credence to the non-similarity of these workers to the others. CONCLUSIONS Based on these results, further studies should focus on improving the knowledge of the characteristics of these workers leading to a better understanding of how to prevent occupational low-back pain.