Evaluation of the Olo Prenatal Nutrition Follow-up Care for Vulnerable Pregnant Women.

Olo nutritional follow-up care offers vulnerable pregnant women food vouchers, multivitamin supplements, tools, and nutritional counselling to support healthy pregnancy outcomes.Purpose: To evaluate the contribution of Olo follow-up care to nutritional intakes and eating practices, as well as to assess the programme-related experience of participants.Methods: Participants (n = 30) responded to questionnaires and web-based 24-hour dietary recalls and participated in a semi-structured interview (n = 10).Results: Olo follow-up care reduced the proportion of participants below the recommended intake for groups for many micronutrients, with the greatest reduction for folate (by 96.7%), vitamin D (by 93.3%), iron (by 70.0%), calcium (by 50.0%), and zinc (by 30.0%), mainly due to the prenatal multivitamin supplements. Most participants (96.7%) did not follow Olo's typical recommendations but, if they had, hypothetically they would have consumed an average of 746 additional calories per day and be above the recommendations for excessive intakes of folic acid and iron (100% and 33.3%, respectively). More than half of the participants were moderately to severely food insecure. Olo contributed to reducing the impact of isolation and increased food accessibility and budget flexibility among participants.Conclusion: Olo follow-up care helped reduce the proportion of women below the recommended intake for micronutrients, but revising the food offered and strategies to address food insecurity may be necessary.

Higher Than Recommended Folic Acid Intakes is Associated with High Folate Status Throughout Pregnancy in a Prospective French-Canadian Cohort.

BACKGROUND: Folate and vitamin B12 status during pregnancy are important for maternal and neonatal health. Maternal intake and prepregnancy body mass index (ppBMI) can influence biomarker status. OBJECTIVES: This study aimed to, throughout pregnancy; 1) assess folate and B12 status including serum total folate, plasma total vitamin B12, and homocysteine (tHcy); 2) examine how these biomarkers are associated with intakes of folate and B12 and with ppBMI; and 3) determine predictors of serum total folate and plasma total vitamin B12. METHODS: In each trimester (T1, T2, and T3), food and supplement intakes of 79 French-Canadian pregnant individuals were assessed by 3 dietary recalls (R24W) and a supplement use questionnaire. Fasting blood samples were collected. Serum total folate and plasma total vitamin B12 and tHcy were assessed by immunoassay (Siemens ADVIA Centaur XP). RESULTS: Participants were 32.1 ± 3.7 y and had a mean ppBMI of 25.7 ± 5.8 kg/m2. Serum total folate concentrations were high (>45.3 nmol/L, T1: 75.4 ± 55.1, T2: 69.1 ± 44.8, T3: 72.1 ± 52.1, P = 0.48). Mean plasma total vitamin B12 concentrations were >220 pmol/L (T1: 428 ± 175, T2: 321 ± 116, T3: 336 ± 128, P < 0.0001). Mean tHcy concentrations were <11 µmol/L across trimesters. Most participants (79.6%-86.1%) had a total folic acid intake above the Tolerable Upper Intake Level (UL, >1000 µg/d). Supplement use accounted for 71.9%-76.1% and 35.3%-41.8% of total folic acid and vitamin B12 intakes, respectively. The ppBMI was not correlated with serum total folate (P > 0.1) but was weakly correlated with and predicted lower plasma total vitamin B12 in T3 (r = -0.23, P = 0.04; r2 = 0.08, standardized beta [sß] = -0.24, P = 0.01). Higher folic acid intakes from supplements predicted higher serum total folate (T1: r2 = 0.05, sß = 0.15, P = 0.04, T2: r2 = 0.28, sß = 0.56, P = 0.01, T3: r2 = 0.19, sß = 0.44, P < 0.0001). CONCLUSIONS: Most pregnant individuals had elevated serum total folate concentrations, reflecting total folic acid intakes above the UL driven by supplement use. Vitamin B12 concentrations were generally adequate and differed by ppBMI and pregnancy stage.

Association between toxic metals, vitamin D and preterm birth in the Maternal-Infant research on environmental chemicals study.

BACKGROUND: Toxic metals, like lead, are risk factors for preterm birth (PTB), but few studies have examined low levels found in most Canadians. Vitamin D, which may have antioxidant activity, protects against PTB. OBJECTIVES: In this study, we investigated the impact of toxic metals (lead, mercury, cadmium and arsenic) on PTB and examined if maternal plasma vitamin D concentrations modify these associations. METHODS: We investigated whether concentrations of metals in whole blood measured in early and late pregnancy were associated with PTB (<37 weeks) and spontaneous PTB in 1851 live births from the Maternal-Infant Research on Environmental Chemicals Study using discrete time survival analysis. We also investigated whether the risk of PTB was modified by first-trimester plasma 25-hydroxyvitamin D (25OHD) concentrations. RESULTS: Of 1851 live births, 6.1% (n = 113) were PTBs and 4.9% (n = 89) were spontaneous PTB. A 1 µg/dL increase in blood lead concentrations during pregnancy was associated with an increased risk of PTB (relative risk [RR] 1.48, 95% confidence interval [CI] 1.00, 2.20) and spontaneous PTB (RR 1.71, 95% CI 1.13, 2.60). The risk was higher in women with insufficient vitamin D concentrations (25OHD <50 nmol/L) for both PTB (RR 2.42, 95% CI 1.01, 5.79) and spontaneous PTB (RR 3.04, 95% CI 1.15, 8.04). However, an interaction on the additive scale was not present. Arsenic was associated with a higher risk of PTB (RR 1.10, 95% CI 1.02, 1.19) and spontaneous PTB (RR 1.11, 95% CI 1.03, 1.20) per 1 µg/L. CONCLUSIONS: Gestational exposure to low levels of lead and arsenic may increase the risk of PTB and spontaneous PTB; individuals with insufficient vitamin D may be more susceptible to the adverse effects of lead. Given our relatively small number of cases, we encourage testing of this hypothesis in other cohorts, especially those with vitamin D-deficient populations.

First-trimester diet quality in association with maternal subcutaneous and visceral adipose tissue thicknesses and glucose homeostasis during pregnancy.

We aimed to characterise the associations between first-trimester diet quality, adiposity, and glucose homeostasis measurements throughout pregnancy in a sample of 104 healthy pregnant women. Three Web-based 24-h recalls were completed, from which the Alternate Healthy Eating Index (AHEI) was calculated. At each trimester (12.5 ± 0.7, 22.8 ± 1.0, and 33.6 ± 1.3 weeks of gestation), fasting glucose and insulin were measured to compute an insulin resistance index (HOMA-IR). Subcutaneous and visceral adipose tissue thicknesses were estimated by ultrasound at the end of the first trimester. Inverse associations were observed between the first-trimester AHEI and first-trimester fasting insulin (r = 0.24; p < 0.05), and HOMA-IR (r = -0.22; p < 0.05), as well as third-trimester fasting insulin (r = -0.20; p < 0.05). A trend was also observed between first-trimester AHEI and first-trimester SAT thickness (r = -0.17; p < 0.1). Pre- and early-pregnancy adiposity measurements were identified as high predictors fasting insulin concentrations throughout pregnancy. Higher early-pregnancy diet quality is associated with more favourable metabolic measurements during pregnancy.

Blood metals and vitamin D status in a pregnancy cohort: A bidirectional biomarker analysis.

Low 25-hydroxyvitamin D (25OHD), a biomarker of vitamin D status, is associated with reduced immune function and adverse pregnancy outcomes, such as preterm birth. Observational studies indicate that long-term, high level exposure to metals such as cadmium (Cd) and lead (Pb) can impact a person's vitamin D status. However, the directionality of the association is uncertain, particularly for low-level exposures. We used three distinct longitudinal data analysis methods to investigate cross-sectional, longitudinal and bidirectional relationships of Cd and Pb biomarkers with 25-hydroxyvitamin D (25OHD) in a Canadian pregnancy cohort. Maternal whole blood Cd and Pb and plasma 25OHD concentrations were measured in the 1st (n = 1905) and 3rd (n = 1649) trimester and at delivery (25OHD only, n = 1542). Our multivariable linear regression analysis showed weak inverse associations between Cd and 25OHD concentrations cross-sectionally and longitudinally while the latent growth curve models showed weak associations with Pb on the 25OHD intercept. In the bidirectional analysis, using cross lagged panel models, we found no association between 1st trimester metals and 3rd trimester 25OHD. Instead, 1st trimester 25OHD was associated with 9% (-15%, -3%) lower 3rd trimester Cd and 3% (-7, 0.1%) lower Pb. These findings suggest the 25OHD may modify metal concentrations in pregnancy and demonstrates the value of controlling for contemporaneous effects and the persistence of a biomarker over time, in order to rule out reverse causation.

Dietary intakes in pregnant women with previous bariatric surgery.

PURPOSE: To (1) assess dietary intakes of pregnant women with previous bariatric surgery in comparison with Dietary Reference Intakes (DRIs); (2) compare their dietary intakes as well as their diet quality with a control group of pregnant women with no history of bariatric surgery. METHODS: Twenty-eight (28) pregnant women with previous surgery (sleeve gastrectomy, n = 7 and biliopancreatic diversion with duodenal switch, n = 21) were matched for pre-pregnancy body mass index with 28 pregnant women with no history of bariatric surgery. In at least one trimester, participants completed a minimum of 2 Web-based 24-h dietary recalls from which energy, macro- and micronutrient intakes as well as the Canadian Healthy Eating Index (C-HEI) were derived. RESULTS: No differences were observed for energy intake between groups. All women had protein intakes within the recommended range, but most women with previous surgery had carbohydrate (67%) and dietary fiber intakes (98%) below recommendations. In both groups, mean total fat, saturated fatty acids, free sugars and sodium intakes were above recommendations, as opposed to mean vitamin D, folic acid and iron dietary intakes below recommendations for most women. Compared with the control group, pregnant women with previous bariatric surgery had lower overall C-HEI scores. CONCLUSION: These results suggest that pregnant women with previous bariatric surgery would benefit from a nutritional follow-up throughout their pregnancy. LEVEL OF EVIDENCE: III: Evidence obtained from well-designed cohort or case-control analytic studies.

Longitudinal Assessment of Vitamin D Status across Trimesters of Pregnancy.

BACKGROUND: The evolution of vitamin D status across pregnancy trimesters and its association with prepregnancy body mass index (ppBMI; in kg/m2) remain unclear. OBJECTIVES: We aimed to 1) assess trimester-specific serum total 25-hydroxyvitamin D [25(OH)D] concentrations, 2) compare those concentrations between ppBMI categories, and 3) examine associations between 25(OH)D concentrations, ppBMI, and vitamin D intake. METHODS: As part of a prospective cohort study, 79 pregnant women with a mean age of 32.1 y and ppBMI of 25.7 kg/m2 were recruited in their first trimester (average 9.3 weeks of gestation). Each trimester, vitamin D intake was assessed by 3 Web-based 24-h recalls and a Web questionnaire on supplement use. Serum total 25(OH)D was measured by LC-tandem MS. Repeated-measures ANOVA was performed to assess the evolution of 25(OH)D concentrations across trimesters of pregnancy and comparisons of 25(OH)D concentrations between ppBMI categories were assessed by 1-factor ANOVAs. Stepwise regression analyses were used to identify determinants of 25(OH)D concentrations in the third trimester. RESULTS: Mean ± SD serum total 25(OH)D concentrations increased across trimesters, even after adjustments for ppBMI, seasonal variation, and vitamin D intake from supplements (67.5 ± 20.4, 86.5 ± 30.9, and 88.3 ± 29.0 nmol/L at mean ± SD 12.6 ± 0.8, 22.5 ± 0.8, and 33.0 ± 0.6 weeks of gestation, respectively; P < 0.0001). In the first and third trimesters, women with a ppBMI ≥30 had lower serum total 25(OH)D concentrations than women with a ppBMI <25 (P < 0.05); however, most had concentrations >40nmol/L by the second trimester. Vitamin D intake from supplements was the strongest determinant of third-trimester serum total 25(OH)D concentrations (r2 = 0.246, ß = 0.51; P < 0.0001). CONCLUSIONS: There was an increase in serum total 25(OH)D concentrations across trimesters, independent of ppBMI, seasonal variation, and vitamin D intake from supplements. Almost all women had serum total 25(OH)D concentrations over the 40- and 50-nmol/L thresholds, thus our study supports the prenatal use of a multivitamin across pregnancy.

Trimester-Specific and Total Gestational Weight Gain in Two Consecutive Pregnancies.

OBJECTIVE: This retrospective study aimed to characterize trimester-specific and total gestational weight gain (GWG) over the course of two consecutive pregnancies, as well as maternal determinants associated with interpregnancy weight change (IPWC) and excessive GWG in the second pregnancy. METHODS: We analyzed the electronic medical records of women who delivered their first two consecutive infants at term between 2001 and 2017. RESULTS: Weight gain trajectories differed between the first and second pregnancy for the 1497 women included in this study, with lower second- and third-trimester weight gain in the second pregnancy. Respectively, 53% and 41% of women had excessive GWG in the first and second pregnancies, with a higher proportion of excessive GWG found in women with a higher body mass index (BMI). Most women (55%) experienced interpregnancy weight gain. Maternal determinants of IPWC were BMI before first pregnancy, first-trimester and total GWG in the first pregnancy, and interpregnancy interval (P < 0.0001). Maternal risk factors associated with excessive GWG in the second pregnancy were excessive total GWG in the first pregnancy (OR 6.23; 95% CI 4.67-8.32), interpregnancy weight gain (OR 1.58; 95% CI 1.19-2.09), and interpregnancy interval (OR 1.18; 95% CI 1.07-1.29) as well as BMI before the second pregnancy (OR 1.04, 95% CI 1.02-1.07). CONCLUSION: Weight gain trajectories differ between consecutive pregnancies. GWG in the first pregnancy is a key determinant for IPWC and GWG in the second pregnancy.

Positive attitudes toward weight gain in late pregnancy are associated with healthy eating behaviours.

PURPOSE: This cross-sectional study examined the associations between 3rd trimester attitudes toward weight gain and (1) pre-pregnancy BMI, (2) gestational weight gain (GWG) and (3) eating behaviours assessed in the 3rd trimester. METHODS: Seventy-nine (79) pregnant women completed the French version of the Pregnancy Weight Gain Attitude Scale (PWGAS), the Three-Factor Eating Questionnaire (TFEQ) and the Intuitive Eating Scale-2 (IES-2) in their 3rd trimester. Total GWG was calculated as the difference between the weight recorded before delivery and self-reported pre-pregnancy weight. RESULTS: Most (55.6%) women gained weight above the Institute of Medicine's (IOM) recommendations, but there was no association between PWGAS scores and total or 3rd trimester GWG. Women with obesity had lower PWGAS total scores compared to women with overweight (3.48 ± 0.6 vs. 3.99 ± 0.3, p = 0.005), indicating more negative attitudes in women with obesity vs. overweight. Higher total PWGAS scores were positively correlated with intuitive eating scores (r = 0.28, p < 0.05), and inversely associated with unfavourable eating behaviours such as dietary restraint (r = - 0.42, p < 0.01). CONCLUSION: Women with positive attitudes toward weight gain reported healthier eating behaviours in late pregnancy, which remains to be confirmed in prospective studies. Interventions addressing body image issues during pregnancy may positively influence pregnant women's health, including eating behaviours. LEVEL OF EVIDENCE: Level III, case-control analytic study.

Changes in Eating Behaviours Throughout Pregnancy: Associations with Gestational Weight Gain and Pre-pregnancy Body Mass Index.

OBJECTIVE: Most pregnant women gain weight above recommended levels, and this weight gain affects mothers' and children's health. Factors influencing gestational weight gain (GWG) are numerous and include eating behaviours. The objective of this study was to evaluate the association between eating behaviours and GWG while considering pre-pregnancy body mass index (BMI). METHODS: Fifty-three (n = 53) women were recruited at 9.4 ± 0.6 gestational weeks. At each trimester, they completed the Three-Factor Eating Questionnaire, which evaluates disinhibition, dietary restraint, and susceptibility to hunger. Using a weight gain curve, trimester-specific GWG was calculated with interpolated weights. Total GWG was calculated as the difference between maternal weight before delivery and self-reported pre-pregnancy weight (Canadian Task Force Classification II-2). RESULTS: Women were aged 31.5 ± 3.5, and 81.1% had a university degree. The proportion of women who gained weight within recommendations was 21%, 28%, and 26%, at each trimester, respectively, and 38% for total pregnancy. Overall, dietary restraint score was lower in the third trimester in comparison with the first (6.1 ± 4.1 vs. 7.2 ± 4.6; P = 0.049), whereas no difference was observed for disinhibition or susceptibility to hunger. Our data suggest that variations in eating behaviours throughout pregnancy were similar among women who exhibited total GWG below, within, or above recommendations (Ptrim × GWG = NS) (NS: not significant; trim: trimester). Similar observations were reported when women were compared according to their pre-pregnancy BMI (Ptrim × BMI = NS). CONCLUSION: Maintaining high levels of restraint may be challenging considering the increase in hunger, which could explain the decrease observed in dietary restraint scores. Changes in eating behaviours were not associated with total GWG or pre-pregnancy BMI.

Do pregnant women eat healthier than non-pregnant women of childbearing age?

We aimed to compare the dietary quality and intake of pregnant women, women planning to conceive and women of childbearing age. Fifty-five pregnant women were matched for age and pre-pregnancy body mass index with 55 women planning to conceive and 55 women of childbearing age. Three Web-based 24-h recalls were completed, from which the Canadian Healthy Eating Index was calculated. Pregnant women had greater overall diet quality scores (66.8 ± 10.7, 60.3 ± 14.1 and 61.4 ± 12.8, in pregnant vs. planning to conceive and childbearing age women, p = .009), explained by a higher intake in fruits, vegetables and grain products and lower intake of foods that are high in fat, sugar or salt. Energy intake was significantly higher in pregnant versus planning to conceive women only (2283 ± 518 vs. 2062 ± 430 kcal, p = .03). Diet quality was greater among pregnant women, but diet quality scores were low in all groups, indicating that healthier dietary behaviours should be encouraged for all childbearing age women.

Weight Changes and Body Image in Pregnant Women: A Challenge for Health Care Professionals.

Body changes concerns and body image dissatisfaction are common during pregnancy. We aimed to examine whether health care professionals (HCPs): (i) believe that women are concerned about body image during pregnancy; (ii) consider it important to question, support, and intervene when pregnant women express body image concerns; (iii) feel comfortable enough in their abilities to question pregnant women with concerns; and (iv) have sufficient knowledge and skills to provide adequate support. A 36-item e-survey, developed by ÉquiLibre in collaboration with an expert committee, was sent to HCPs via email. HCPs believe that some situations are associated with body image concerns: postpregnancy weight loss (74.0%), perceived changes in their appearance (65.9%), excessive weight gain (65.3%), and feeling less in control of their body (36.8%). Among 321 responders, 60% considered it important to question pregnant women's concerns. One in four (25.4%) considered themselves "totally comfortable" asking about weight and body image concerns. Our study showed that HCPs need to be better supported in developing their abilities to help weight-preoccupied pregnant women. There is an urgent need to clarify HCPs' roles and to delineate the referral process as well as to ensure staff availability, in terms of time and personnel.

Relationship Between Psychosocial Factors, Dietary Intake and Gestational Weight Gain: A Narrative Review.

Inadequate gestational weight gain (GWG), which has reached almost two-thirds of Canadian pregnant women, is associated with several adverse effects both in the mother and her child. The aim of this review was to establish how psychosocial factors, diet and GWG are interrelated during pregnancy. More specifically, it aimed to evaluate how psychosocial factors can impact on diet and, thus, influence GWG. Studies published through May 2017 that examined factors related to GWG were included. Of 3268 non-duplicate titles and abstract, 77 articles underwent full-text review. Regarding dietary intakes, the majority of the included studies demonstrated that a higher caloric intake was associated with an elevated GWG. Also, a negative body image and attitude toward weight gain as well as a poor knowledge of GWG recommendations and inadequate prenatal care is associated with an increased GWG. Only few studies examined altogether the factors included and conclusions about how psychosocial factors can impact on diet and, thus, influence GWG cannot be drawn at this point. In the few studies that evaluated the interrelationships between psychosocial factors, diet and GWG, energy intake was not identified as a mediator of the association between psychosocial factors and GWG. This review highlights the scarcity of findings regarding psychosocial and dietary factors in relation to GWG and the need for high quality prospective cohort studies that will include all these factors to provide a better understanding of how they are interrelated to influence short- and long-term health.

Associations between maternal triclosan concentrations in early pregnancy and gestational diabetes mellitus, impaired glucose tolerance, gestational weight gain and fetal markers of metabolic function.

BACKGROUND: Triclosan is a phenolic biocide used in a multitude of consumer products and in health care settings. It is widely detected in the American and Canadian populations and has been shown in animal models to act as an endocrine disrupting agent. However, there has been little examination to date of the effects of triclosan exposure in pregnancy on perinatal metabolic outcomes in human populations. METHODS: Using data from the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a Canadian pregnancy cohort, we measured associations of first-trimester urinary triclosan concentrations with total gestational weight gain, gestational diabetes mellitus and impaired glucose tolerance in pregnancy, and fetal markers of metabolic function. Leptin and adiponectin were measured in plasma from umbilical cord blood samples in term neonates and categorized into low (< 10th percentile), intermediate (10th-90th percentile) and high (> 90th percentile) levels. Triclosan concentrations were grouped into quartiles and associations with study outcomes were examined using logistic regression models with adjustment for maternal age, race/ethnicity, pre-pregnancy BMI, education and urinary specific gravity. Restricted cubic spline analysis was performed to help assess linearity and shape of any dose-response relationships. All analyses for leptin and adiponectin levels were performed on the entire cohort as well as stratified by fetal sex. RESULTS: Triclosan measures were available for 1795 MIREC participants with a live born singleton birth. Regression analyses showed a non-significant inverse association between triclosan concentrations and leptin levels above the 90th percentile that was restricted to female fetuses (OR for highest quartile of triclosan compared to lowest quartile = 0.4 (95% CI 0.2-1.1), p-value for trend across quartiles = 0.02). Triclosan concentrations in the second quartile were associated with elevated odds of adiponectin below the 10th percentile in male fetuses (OR for Q2 compared to Q1 = 2.5, 95% CI 1.1-5.9, p-value for trend across quartiles = 0.93). No significant linear associations between triclosan concentrations and leptin or adiponectin levels in overall or sex-specific analyses were observed from restricted cubic spline analyses. No significant associations were observed in adjusted analyses between triclosan concentrations and gestational diabetes mellitus, impaired glucose tolerance or gestational weight gain. CONCLUSIONS: This study does not support an association between triclosan concentrations in pregnancy and fetal metabolic markers, glucose disorders of pregnancy, or excessive gestational weight gain.

Validation of a self-administered web-based 24-hour dietary recall among pregnant women.

BACKGROUND: The use of valid dietary assessment methods is crucial to analyse adherence to dietary recommendations among pregnant women. This study aims to assess the relative validity of a self-administered Web-based 24-h dietary recall, the R24W, against a pen-paper 3-day food record (FR) among pregnant women. METHODS: Sixty (60) pregnant women recruited at 9.3 ± 0.7 weeks of pregnancy in Quebec City completed, at each trimester, 3 R24W and a 3-day FR. Mean energy and nutrient intakes reported by both tools were compared using paired Student T-Tests. Pearson correlations were used to analyze the association between both methods. Agreement between the two methods was evaluated using cross-classification analyses, weighted kappa coefficients and Bland-Altman analyses. RESULTS: Pearson correlation coefficients were all significant, except for vitamin B12 (r = 0.03; p = 0.83) and ranged from 0.27 to 0.76 (p < 0.05). Differences between mean intakes assessed by the R24W and the FR did not exceed 10% in 19 variables and were not significant for 16 out of 26 variables. In cross-classification analyses, the R24W ranked, on average, 79.1% of participants in the same or adjacent quartiles as the FR. CONCLUSIONS: Compared to a 3-day FR, the R24W is a valid method to assess intakes of energy and most nutrients but may be less accurate in the evaluation of intakes of fat (as a proportion of energy intake), vitamin D, zinc and folic acid. During pregnancy, the R24W was a more accurate tool at a group-level than at an individual-level and should, therefore, be used in an epidemiological rather than a clinical setting. The R24W may be particularly valuable as a tool used in cohort studies to provide valid information on pregnant women's dietary intakes and facilitate evaluation of associations between diet and adverse pregnancy outcomes.

Disparities in the timing and measurement methods to assess vitamin D status during pregnancy: A Narrative Review.

Studies that examined associations between low circulating 25-hydroxyvitamin D (25(OH)D) and adverse pregnancy outcomes used various designs, assay methods and time points for measurement of 25(OH)D concentrations, which creates some confusion in the current literature. We aimed to investigate the variability in the timing and measurement methods used to evaluate vitamin D status during pregnancy. Analysis of 198 studies published between 1976 and 2017 showed an important variability in the choice of 1) threshold values for 25(OH)D insufficiency or deficiency, 2) 25(OH)D measurement methods, and 3) trimester in which 25(OH)D concentrations were measured. Blood samples were taken once during pregnancy in a large majority of studies, which may not be representative of vitamin D status throughout pregnancy. Most studies reported adjustment for confounding factors including season of blood sampling, but very few studies used the 25(OH)D gold standard assay, the LC-MS/MS. Prospective studies assessing maternal 25(OH)D concentrations 1) by standardized and validated methods, 2) at various time points during pregnancy, and 3) after considering potential confounding factors, are needed.

Prepregnancy Body Mass Index as a Significant Predictor of Total Gestational Weight Gain and Birth Weight.

PURPOSE: We aimed to describe adherence to gestational weight gain (GWG) recommendations and identify determinants of excessive GWG in a sample of women from Quebec, Canada. METHODS: Data were collected from the multi-centre 3D (Design, Develop, Discover) pregnancy cohort study, which included women who delivered between May 2010 and August 2012 at 9 obstetrical hospitals in Quebec, Canada. GWG was calculated for 1145 women and compared to the 2009 Institute of Medicine (IOM) recommendations. RESULTS: Overall, 51% of participants exceeded the recommendations. Approximately 68% of women with obesity gained weight in excess of the IOM recommendations. The corresponding numbers were 75%, 44%, and 27% in overweight, normal weight, and underweight women, respectively. A prepregnancy BMI of 25 kg/m2 or more was the only significant predictor of exceeding GWG recommendations (OR 3.35, 95% CI 2.44-4.64) in a multivariate model. Birth weight was positively associated with GWG. GWG and prepregnancy BMI could explain 3.13% and 2.46% of the variance in birth weight, respectively. CONCLUSION: About half of women exceeded GWG recommendations, and this was correlated with infant birth weight. This reinforces the need to develop and evaluate strategies, including nutritional interventions, for pregnant women to achieve optimal GWG.

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.

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 ß-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.

The increase in serum 25-hydroxyvitamin D following weight loss does not contribute to the improvement in insulin sensitivity, insulin secretion and ß-cell function.

Serum 25-hydroxyvitamin D (25(OH)D) concentrations have been reported to increase following weight loss. Moreover, both weight loss and higher serum 25(OH)D concentrations have been associated with a lower risk of developing type 2 diabetes. The objective of the present study was to determine whether the increase in serum 25(OH)D concentration following weight loss is associated with improved insulin sensitivity, insulin secretion and disposition index (ß-cell function). Data from two prospective lifestyle modification studies had been combined. Following a lifestyle-modifying weight loss intervention for 1 year, eighty-four men and women with prediabetes and a BMI ≥ 27 kg/m(2) were divided based on weight loss at 1 year: < 5% (non-responders, n 56) and ≥ 5% (responders, n 28). The association between the change in serum 25(OH)D concentration and changes in insulin sensitivity (homeostasis model assessment of insulin sensitivity (HOMA%S) and Matsuda), insulin secretion (AUC of C-peptide) and disposition index after adjustment for weight loss was examined. Participants in the responders' group lost on average 9.5% of their weight when compared with non-responders who lost only 0.8% of weight. Weight loss in responders resulted in improved insulin sensitivity (HOMA%S, P = 0.0003) and disposition index (P = 0.02); however, insulin secretion remained unchanged. The rise in serum 25(OH)D concentration following weight loss in responders was significantly higher than that in non-responders (8.9 (SD 12.5) v. 3.6 (SD 10.7) nmol/l, P = 0.05). However, it had not been associated with amelioration of insulin sensitivity and ß-cell function, even after adjustment for weight loss and several confounders. In conclusion, the increase in serum 25(OH)D concentration following weight loss does not contribute to the improvement in insulin sensitivity or ß-cell function.