Patricia Monnier

Cohort Profile: The Maternal-Infant Research on Environmental Chemicals Research Platform

BACKGROUND The Maternal-Infant Research on Environmental Chemicals (MIREC) Study was established to obtain Canadian biomonitoring data for pregnant women and their infants, and to examine potential adverse health effects of prenatal exposure to priority environmental chemicals on pregnancy and infant health. METHODS Women were recruited during the first trimester from 10 sites across Canada and were followed through delivery. Questionnaires were administered during pregnancy and post-delivery to collect information on demographics, occupation, life style, medical history, environmental exposures and diet. Information on the pregnancy and the infant was abstracted from medical charts. Maternal blood, urine, hair and breast milk, as well as cord blood and infant meconium, were collected and analysed for an extensive list of environmental biomarkers and nutrients. Additional biospecimens were stored in the studys Biobank. The MIREC Research Platform encompasses the main cohort study, the Biobank and follow-up studies. RESULTS Of the 8716 women approached at early prenatal clinics, 5108 were eligible and 2001 agreed to participate (39%). MIREC participants tended to smoke less (5.9% vs. 10.5%), be older (mean 32.2 vs. 29.4 years) and have a higher education (62.3% vs. 35.1% with a university degree) than women giving birth in Canada. CONCLUSIONS The MIREC Study, while smaller in number of participants than several of the international cohort studies, has one of the most comprehensive datasets on prenatal exposure to multiple environmental chemicals. The biomonitoring data and biological specimen bank will make this research platform a significant resource for examining potential adverse health effects of prenatal exposure to environmental chemicals.

A Cluster-Randomized Trial to Reduce Cesarean Delivery Rates in Quebec

BACKGROUND In Canada, cesarean delivery rates have increased substantially over the past decade. Effective, safe strategies are needed to reduce these rates. METHODS We conducted a cluster-randomized, controlled trial of a multifaceted 1.5-year intervention at 32 hospitals in Quebec. The intervention involved audits of indications for cesarean delivery, provision of feedback to health professionals, and implementation of best practices. The primary outcome was the cesarean delivery rate in the 1-year postintervention period. RESULTS Among the 184,952 participants, 53,086 women delivered in the year before the intervention and 52,265 women delivered in the year following the intervention. There was a significant but small reduction in the rate of cesarean delivery from the preintervention period to the postintervention period in the intervention group as compared with the control group (change, 22.5% to 21.8% in the intervention group and 23.2% to 23.5% in the control group; odds ratio for incremental change over time, adjusted for hospital and patient characteristics, 0.90; 95% confidence interval [CI], 0.80 to 0.99; P=0.04; adjusted risk difference, -1.8%; 95% CI, -3.8 to -0.2). The cesarean delivery rate was significantly reduced among women with low-risk pregnancies (adjusted risk difference, -1.7%; 95% CI, -3.0 to -0.3; P=0.03) but not among those with high-risk pregnancies (P=0.35; P = 0.03 for interaction). The intervention group also had a reduction in major neonatal morbidity as compared with the control group (adjusted risk difference, -0.7%; 95% CI, -1.3 to -0.1; P=0.03) and a smaller increase in minor neonatal morbidity (adjusted risk difference, -1.7%; 95% CI, -2.6 to -0.9; P<0.001). Changes in minor and major maternal morbidity did not differ significantly between the groups. CONCLUSIONS Audits of indications for cesarean delivery, feedback for health professionals, and implementation of best practices, as compared with usual care, resulted in a significant but small reduction in the rate of cesarean delivery, without adverse effects on maternal or neonatal outcomes. The benefit was driven by the effect of the intervention in low-risk pregnancies. (Funded by the Canadian Institutes of Health Research; QUARISMA Current Controlled Trials number, ISRCTN95086407.).

Exposure to phthalates, bisphenol A and metals in pregnancy and the association with impaired glucose tolerance and gestational diabetes mellitus: The MIREC study.

BACKGROUND Studies from several countries report increases in rates of gestational diabetes mellitus (GDM) over recent decades. Exposure to environmental chemicals could contribute to this trend. OBJECTIVES To determine the associations between plasticisers and metals measured in early pregnancy with impaired glucose tolerance (IGT) and GDM in a Canadian pregnancy cohort. METHODS Women enrolled in the Maternal-Infant Research on Environmental Chemicals (MIREC) Study were included if they had a singleton delivery and did not have pre-existing diabetes. Eleven phthalate metabolites and total bisphenol A (BPA) were measured in first-trimester urine samples, and four metals (lead, cadmium, mercury and arsenic) were measured in first-trimester blood samples. IGT and GDM were assessed in accordance with standard guidelines by chart review. Chemical concentrations were grouped by quartiles, and associations with outcomes were examined using logistic regression with adjustment for maternal age, race, pre-pregnancy BMI, and education. Restricted cubic spline analysis was performed to help assess linearity and nature of any dose-response relationships. RESULTS Of 2001 women recruited into the MIREC cohort, 1274 met the inclusion criteria and had outcome data and biomonitoring data measured for at least one of the chemicals we examined. Elevated odds of GDM were observed in the highest quartile of arsenic exposure (OR = 3.7, 95% CI = 1.4-9.6) in the adjusted analyses. A significant dose-response relationship was observed in a cubic spline model between arsenic and odds of GDM (p < 0.01). No statistically significant associations were observed between phthalates or BPA or other metals with IGT or GDM. CONCLUSIONS Our findings add to the growing body of evidence supporting the role of maternal arsenic exposure as a risk factor for gestational diabetes.

A birth cohort study to investigate the association between prenatal phthalate and bisphenol A exposures and fetal markers of metabolic dysfunction

BackgroundObesity and type-2 diabetes are on the rise and in utero exposure to environmental contaminants is a suspected contributing factor. Our objective was to examine associations between prenatal exposure to potential endocrine disrupting chemicals and markers of fetal metabolic dysfunction.MethodsThe Maternal-Infant Research on Environmental Chemicals Study (MIREC) recruited 2001 women during the first trimester of pregnancy from 10 Canadian sites. First trimester maternal urine was measured for 11 phthalate metabolites and bisphenol A (BPA). Leptin and adioponectin measured in 1,363 available umbilical cord blood samples served as markers of metabolic function. Restricted cubic spline curves were used to assess the relationship between continuous measures of phthalate and BPA levels and cord blood adipokines. Polytomous logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI) for the association between phthalates and BPA and both high (≥90th percentile) and low (≤10th percentile) fetal adiponectin and leptin, adjusting for confounding factors. Analyses were conducted for all subjects, overall, and separately by fetal sex.ResultsLeptin was significantly higher in female than male infants. We observed an inverse, non-linear relationship between BPA and adiponectin among males in the restricted cubic spline and linear regression analysis. Mono-(3-carboxypropyl) (MCPP) was associated with increased odds of high leptin among males in the polytomous logistic regression models (4th quartile OR = 3.5 95% CI: 1.1-11.6).ConclusionOur findings contribute to the growing body of evidence examining the influence of early life exposure on metabolic regulation and function. Associations between maternal exposure to chemicals and markers of metabolic function appear to be potentially sex specific. However, further investigation is required to determine whether in utero and childhood exposure to BPA and phthalates are associated with metabolic dysfunctions later in life.

Prevalence of human papillomaviruses in semen: a systematic review and meta-analysis

STUDY QUESTION What is the prevalence of human papillomavirus (HPV) in semen? SUMMARY ANSWER HPV is present in the semen of asymptomatic men, with a pooled prevalence in a random effects meta-analysis of populations seeking fertility evaluation/treatment of 16%, versus 10% in other populations. WHAT IS KNOWN ALREADY The main risk of donor insemination (DI) is known to be contamination with an infectious agent. HPV is the necessary cause of cervical cancer, and plays an etiologic role in other anogenital cancers. Although it is known to be prevalent and sexually transmitted, donor semen specimens are not tested for the presence of HPV. STUDY DESIGN, SIZE, DURATION A systematic review and meta-analysis of studies published between January 1980 and June 2013 were performed. Variables collected included characteristics of study populations, method of semen preparation, HPV DNA detection and genotyping, HPV types targeted and proportion of HPV positivity. PARTICIPANTS/MATERIALS, SETTING, METHODS Two investigators independently assessed the studies for inclusion in the review and abstracted the data, while others reviewed the extracted data in detail. Studies were included if they provided data on HPV DNA prevalence in semen and PCR-based methods were used. For the meta-analysis, reports were separated according to the study populations, creating two distinct subgroups: populations seeking fertility evaluation/treatments, and other populations. Data were analysed using a random effects model for each subpopulation. MAIN RESULTS AND THE ROLE OF CHANCE The literature search identified 285 studies, and in the 27 studies that were included the HPV DNA prevalence in 4029 semen samples varied from 0 to 100%. The three studies focusing on sperm donors identified HPV DNA in 26.3, 7.5 and 16.0% of semen samples. HPV-16 was the most common type overall. The pooled prevalence in a random effects meta-analysis of seven studies focusing on infertile populations was 16% [95% confidence interval (CI): 10-23%] versus 10% (95% CI: 7-14%) in 11 reports focusing on other populations. LIMITATIONS, REASONS FOR CAUTION First, despite defining clinically relevant subgroups, substantial heterogeneity remained. Secondly, although we retrieved data from reports in English or French only, after reviewing the five reports in other languages only two more could have been added and, as their prevalence estimates were similar to those of studies included in our review, we do not believe that exclusion of these reports biased our results or conclusions. WIDER IMPLICATIONS OF THE FINDINGS HPV DNA can be found in donor semen and preliminary studies confirm genome activity. For this reason, and although the exact consequences of insemination with HPV-infected semen (cervical infections/lesions, impact on success rate of DI) remain to be clarified, we believe that HPV-infected sperm should be considered a health risk unless well-designed studies prove otherwise. The development and validation of adequate sperm washing techniques before DI appears to be a promising option. STUDY FUNDING/COMPETING INTEREST(S) C.L. and P.M. have no conflicts of interests relevant to the submitted work. H.T. has served as a consultant and on advisory boards and has received speaker fees and travel assistance from Merck-Frosst Canada, Glaxo SmithKline Pharmaceuticals, Belgium and Gilead Sciences. F.C. has received grants through his institution from Merck and Roche, as well as honoraria from Merck and Roche for lectures on HPV. M.-H.M. has received grants though her institution from Merck and Qiagen and lecture honoraria from Merck and GSK for conferences on HPV and best practices in cervical cancer prevention. TRIAL REGISTRATION NUMBER N/A.

Exposure to organophosphorus and organochlorine pesticides, perfluoroalkyl substances, and polychlorinated biphenyls in pregnancy and the association with impaired glucose tolerance and gestational diabetes mellitus: The MIREC Study.

BACKGROUND Studies report increases in rates of gestational diabetes mellitus (GDM) over recent decades. Environmental chemicals may increase the risk of diabetes through impacts on glucose metabolism, mitochondrial dysfunction, and endocrine-disrupting mechanisms including effects on pancreatic β-cell function and adiponectin release. OBJECTIVES To determine the associations between pesticides, perfluoroalkyl substances (PFASs) and polychlorinated biphenyls (PCBs) measured in early pregnancy and impaired glucose tolerance (IGT) and GDM in a Canadian birth cohort. METHODS Women enrolled in the Maternal-Infant Research on Environmental Chemicals (MIREC) Study were included if they had a singleton delivery and did not have pre-existing diabetes. Exposure variables included three organophosphorus (OP) pesticide metabolites detected in first-trimester urine samples, as well as three organochlorine (OC) pesticides, three PFASs, and four PCBs in first-trimester blood samples. Gestational IGT and GDM were assessed by chart review in accordance with published guidelines. Adjusted logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CI) for the association between quartiles of environmental chemicals and both gestational IGT and GDM. RESULTS Of the 2001 women recruited into the MIREC cohort, 1274 met the inclusion criteria and had outcome and biomonitoring data available. Significantly lower odds of GDM were observed in the third and fourth quartiles of dimethylphosphate (DMP) and in the fourth quartile of dimethylthiophosphate (DMTP) in adjusted analyses (DMP Q3: OR=0.2, 95% CI=0.1-0.7; DMP Q4: OR=0.3, 95% CI=0.1-0.8; DMTP: OR=0.3, 95% CI=0.1-0.9). Significantly elevated odds of gestational IGT was observed in the second quartile of perfluorohexane sulfonate (PFHxS) (OR=3.5, 95% CI=1.4-8.9). No evidence of associations with GDM or IGT during pregnancy was observed for PCBs or OC pesticides. CONCLUSIONS We did not find consistent evidence for any positive associations between the chemicals we examined and GDM or IGT during pregnancy. We observed statistical evidence of inverse relationships between urine concentrations of DMP and DMTP with GDM. We cannot rule out the influence of residual confounding due to unmeasured protective factors, such as nutritional benefits from fruit and vegetable consumption, also associated with pesticide exposure, on the observed inverse associations between maternal OP pesticide metabolites and GDM. These findings require further investigation.

Air Pollution Exposure During Pregnancy and Fetal Markers of Metabolic Function The MIREC Study

Previous evidence suggests that exposure to outdoor air pollution during pregnancy could alter fetal metabolic function, which could increase the risk of obesity in childhood. However, to our knowledge, no epidemiologic study has investigated the association between prenatal exposure to air pollution and indicators of fetal metabolic function. We investigated the association between maternal exposure to nitrogen dioxide and fine particulate matter (aerodynamic diameter ≤2.5 µm) and umbilical cord blood leptin and adiponectin levels with mixed-effects linear regression models among 1,257 mother-infant pairs from the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, conducted in Canada (2008-2011). We observed that an interquartile-range increase in average exposure to fine particulate matter (3.2 µg/m(3)) during pregnancy was associated with an 11% (95% confidence interval: 4, 17) increase in adiponectin levels. We also observed 13% (95% confidence interval: 6, 20) higher adiponectin levels per interquartile-range increase in average exposure to nitrogen dioxide (13.6 parts per billion) during pregnancy. Significant associations were seen between air pollution markers and cord blood leptin levels in models that adjusted for birth weight z score but not in models that did not adjust for birth weight z score. The roles of prenatal exposure to air pollution and fetal metabolic function in the potential development of childhood obesity should be further explored.

3D Cohort Study: The Integrated Research Network in Perinatology of Quebec and Eastern Ontario.

Abstract Background The 3D Cohort Study (Design, Develop, Discover) was established to help bridge knowledge gaps about the links between various adverse exposures during pregnancy with birth outcomes and later health outcomes in children. Methods Pregnant women and their partners were recruited during the first trimester from nine sites in Quebec and followed along with their children through to 2 years of age. Questionnaires were administered during pregnancy and post‐delivery to collect information on demographics, mental health and life style, medical history, psychosocial measures, diet, infant growth, and neurodevelopment. Information on the delivery and newborn outcomes were abstracted from medical charts. Biological specimens were collected from mothers during each trimester, fathers (once during the pregnancy), and infants (at delivery and 2 years of age) for storage in a biological specimen bank. Results Of the 9864 women screened, 6348 met the eligibility criteria and 2366 women participated in the study (37% of eligible women). Among women in the 3D cohort, 1721 of their partners (1704 biological fathers) agreed to participate (73%). Two thousand two hundred and nineteen participants had a live singleton birth (94%). Prenatal blood and urine samples as well as vaginal secretions were collected for ≥98% of participants, cord blood for 81% of livebirths, and placental tissue for 89% of livebirths. Conclusions The 3D Cohort Study combines a rich bank of multiple biological specimens with extensive clinical, life style, and psychosocial data. This data set is a valuable resource for studying the developmental etiology of birth and early childhood neurodevelopmental outcomes.

Maternal blood metal levels and fetal markers of metabolic function

Exposure to metals commonly found in the environment has been hypothesized to be associated with measures of fetal growth but the epidemiological literature is limited. The Maternal-Infant Research on Environmental Chemicals (MIREC) study recruited 2001 women during the first trimester of pregnancy from 10 Canadian sites. Our objective was to assess the association between prenatal exposure to metals (lead, arsenic, cadmium, and mercury) and fetal metabolic function. Average maternal metal concentrations in 1st and 3rd trimester blood samples were used to represent prenatal metals exposure. Leptin and adiponectin were measured in 1363 cord blood samples and served as markers of fetal metabolic function. Polytomous logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI) for the association between metals and both high (≥ 90%) and low (≤ 10%) fetal adiponectin and leptin levels. Leptin levels were significantly higher in female infants compared to males. A significant relationship between maternal blood cadmium and odds of high leptin was observed among males but not females in adjusted models. When adjusting for birth weight z-score, lead was associated with an increased odd of high leptin. No other significant associations were found at the top or bottom 10th percentile in either leptin or adiponectin models. This study supports the proposition that maternal levels of cadmium influence cord blood adipokine levels in a sex-dependent manner. Further investigation is required to confirm these findings and to determine how such findings at birth will translate into childhood anthropometric measures.

Maternal Concentrations of Perfluoroalkyl Substances and Fetal Markers of Metabolic Function and Birth Weight The Maternal-Infant Research on Environmental Chemicals (MIREC) Study

Abstract Perfluoroalkyl substances (PFAS) are ubiquitous, persistent chemicals that have been widely used in the production of common household and consumer goods for their nonflammable, lipophobic, and hydrophobic properties. Inverse associations between maternal or umbilical cord blood concentrations of perfluorooctanoic acid and perfluorooctanesulfonate and birth weight have been identified. This literature has primarily examined each PFAS individually without consideration of the potential influence of correlated exposures. Further, the association between PFAS exposures and indicators of metabolic function (i.e., leptin and adiponectin) has received limited attention. We examined associations between first-trimester maternal plasma PFAS concentrations and birth weight and cord blood concentrations of leptin and adiponectin using data on 1,705 mother-infant pairs from the Maternal Infant Research on Environmental Chemicals (MIREC) Study, a trans-Canada birth cohort study that recruited women between 2008 and 2011. Bayesian hierarchical models were used to quantify associations and calculate credible intervals. Maternal perfluorooctanoic acid concentrations were inversely associated with birth weight z score, though the null value was included in all credible intervals (log10 β = −0.10, 95% credible interval: −0.34, 0.13). All associations between maternal PFAS concentrations and cord blood adipocytokine concentrations were of small magnitude and centered around the null value. Follow-up in a cohort of children is required to determine how the observed associations manifest in childhood.