Gestational age at birth and body size from infancy through adolescence: An individual participant data meta-analysis on 253,810 singletons in 16 birth cohort studies.

BACKGROUND: Preterm birth is the leading cause of perinatal morbidity and mortality and is associated with adverse developmental and long-term health outcomes, including several cardiometabolic risk factors and outcomes. However, evidence about the association of preterm birth with later body size derives mainly from studies using birth weight as a proxy of prematurity rather than an actual length of gestation. We investigated the association of gestational age (GA) at birth with body size from infancy through adolescence. METHODS AND FINDINGS: We conducted a two-stage individual participant data (IPD) meta-analysis using data from 253,810 mother-child dyads from 16 general population-based cohort studies in Europe (Denmark, Finland, France, Italy, Norway, Portugal, Spain, the Netherlands, United Kingdom), North America (Canada), and Australasia (Australia) to estimate the association of GA with body mass index (BMI) and overweight (including obesity) adjusted for the following maternal characteristics as potential confounders: education, height, prepregnancy BMI, ethnic background, parity, smoking during pregnancy, age at child's birth, gestational diabetes and hypertension, and preeclampsia. Pregnancy and birth cohort studies from the LifeCycle and the EUCAN-Connect projects were invited and were eligible for inclusion if they had information on GA and minimum one measurement of BMI between infancy and adolescence. Using a federated analytical tool (DataSHIELD), we fitted linear and logistic regression models in each cohort separately with a complete-case approach and combined the regression estimates and standard errors through random-effects study-level meta-analysis providing an overall effect estimate at early infancy (>0.0 to 0.5 years), late infancy (>0.5 to 2.0 years), early childhood (>2.0 to 5.0 years), mid-childhood (>5.0 to 9.0 years), late childhood (>9.0 to 14.0 years), and adolescence (>14.0 to 19.0 years). GA was positively associated with BMI in the first decade of life, with the greatest increase in mean BMI z-score during early infancy (0.02, 95% confidence interval (CI): 0.00; 0.05, p < 0.05) per week of increase in GA, while in adolescence, preterm individuals reached similar levels of BMI (0.00, 95% CI: -0.01; 0.01, p 0.9) as term counterparts. The association between GA and overweight revealed a similar pattern of association with an increase in odds ratio (OR) of overweight from late infancy through mid-childhood (OR 1.01 to 1.02) per week increase in GA. By adolescence, however, GA was slightly negatively associated with the risk of overweight (OR 0.98 [95% CI: 0.97; 1.00], p 0.1) per week of increase in GA. Although based on only four cohorts (n = 32,089) that reached the age of adolescence, data suggest that individuals born very preterm may be at increased odds of overweight (OR 1.46 [95% CI: 1.03; 2.08], p < 0.05) compared with term counterparts. Findings were consistent across cohorts and sensitivity analyses despite considerable heterogeneity in cohort characteristics. However, residual confounding may be a limitation in this study, while findings may be less generalisable to settings in low- and middle-income countries. CONCLUSIONS: This study based on data from infancy through adolescence from 16 cohort studies found that GA may be important for body size in infancy, but the strength of association attenuates consistently with age. By adolescence, preterm individuals have on average a similar mean BMI to peers born at term.

Correction: Gestational age at birth and body size from infancy through adolescence: An individual participant data meta-analysis on 253,810 singletons in 16 birth cohort studies.

[This corrects the article DOI: 10.1371/journal.pmed.1004036.].

Developing non-response weights to account for attrition-related bias in a longitudinal pregnancy cohort.

BACKGROUND: Prospective cohorts may be vulnerable to bias due to attrition. Inverse probability weights have been proposed as a method to help mitigate this bias. The current study used the "All Our Families" longitudinal pregnancy cohort of 3351 maternal-infant pairs and aimed to develop inverse probability weights using logistic regression models to predict study continuation versus drop-out from baseline to the three-year data collection wave. METHODS: Two methods of variable selection took place. One method was a knowledge-based a priori variable selection approach, while the second used Least Absolute Shrinkage and Selection Operator (LASSO). The ability of each model to predict continuing participation through discrimination and calibration for both approaches were evaluated by examining area under the receiver operating curve (AUROC) and calibration plots, respectively. Stabilized inverse probability weights were generated using predicted probabilities. Weight performance was assessed using standardized differences of baseline characteristics for those who continue in study and those that do not, with and without weights (unadjusted estimates). RESULTS: The a priori and LASSO variable selection method prediction models had good and fair discrimination with AUROC of 0.69 (95% Confidence Interval [CI]: 0.67-0.71) and 0.73 (95% CI: 0.71-0.75), respectively. Calibration plots and non-significant Hosmer-Lemeshow Goodness of Fit Tests indicated that both the a priori (p = 0.329) and LASSO model (p = 0.242) were well-calibrated. Unweighted results indicated large (> 10%) standardized differences in 15 demographic variables (range: 11 - 29%), when comparing those who continued in the study with those that did not. Weights derived from the a priori and LASSO models reduced standardized differences relative to unadjusted estimates, with the largest differences of 13% and 5%, respectively. Additionally, when applying the same LASSO variable selection method to develop weights in future data collection waves, standardized differences remained below 10% for each demographic variable. CONCLUSION: The LASSO variable selection approach produced robust weights that addressed non-response bias more than the knowledge-driven approach. These weights can be applied to analyses across multiple longitudinal waves of data collection to reduce bias.

Small for date preterm infants and risk of higher blood pressure in later life: A systematic review and meta-analysis.

BACKGROUND: Historical reports suggest that infants born small for gestational age (SGA) are at increased risk for high blood pressure (BP) at older ages after adjustment for later age body size. Such adjustment may be inappropriate since adiposity is a known cause of cardiovascular and metabolic disease. OBJECTIVES: To assess the association between SGA births and later BP among preterm births, considering potential background confounders and over-adjustment for later body size. METHODS: A database search of studies up to October 2022 included MEDLINE, EMBASE and CINAHL. Studies were included if they reported BP (systolic [SBP] or diastolic [DBP]) (outcomes) for participants born preterm with SGA (exposure) or non-SGA births. All screening, extraction steps, and risk of bias (using the Risk of Bias In Non-randomised Studies of Interventions [ROBINS-I] tool) were conducted in duplicate by two reviewers. Data were pooled in meta-analysis using random-effects models. We explored potential sources of heterogeneity. RESULTS: We found no meaningful difference in later BP between preterm infants with and without SGA status at birth. Meta-analysis of 25 studies showed that preterm SGA, compared to preterm non-SGA, was not associated with higher BP at age 2 and older with mean differences for SBP 0.01 mmHg (95% CI -0.10, 0.12, I2  = 59.8%, n = 20,462) and DBP 0.01 mm Hg (95% CI -0.10, 0.12), 22 studies, (I2  = 53.0%, n = 20,182). Adjustment for current weight did not alter the results, which could be due to the lack of differences in later weight status in most of the included studies. The included studies were rated to be at risk of bias due to potential residual confounding, with a low risk of bias in other domains. CONCLUSIONS: Evidence indicates that preterm infants born SGA are not at increased risk of developing higher BP as children or as adults as compared to non-SGA preterm infants.

Small for gestational age preterm infants and later adiposity and height: A systematic review and meta-analysis.

BACKGROUND: Overweight and obesity and their consequent morbidities are important worldwide health problems. Some research suggests excess adiposity origins may begin in fetal life, but unknown is whether this applies to infants born preterm. OBJECTIVE: The objective of the study was to assess the association between small for gestational age (SGA) birth and later adiposity and height among those born preterm. DATA SOURCES: MEDLINE, EMBASE and CINAHL until October 2022. STUDY SELECTION AND DATA EXTRACTION: Studies were included if they reported anthropometric (adiposity measures and height) outcomes for participants born preterm with SGA versus non-SGA. Screening, data extraction and risks of bias assessments were conducted in duplicate by two reviewers. SYNTHESIS: We meta-analysed across studies using random-effects models and explored potential heterogeneity sources. RESULTS: Thirty-nine studies met the inclusion criteria. In later life, preterm SGA infants had a lower body mass index (-0.66 kg/m2 , 95% CI -0.79, -0.53; 32 studies, I2 = 16.7, n = 30,346), waist circumference (-1.20 cm, 95% CI -2.17, -0.23; 13 studies, I2 = 19.4, n = 2061), lean mass (-2.62 kg, 95% CI -3.45, 1.80; 7 studies, I2 = 0, n = 205) and height (-3.85 cm, 95% CI -4.73, -2.96; 26 studies, I2 = 52.6, n = 4174) compared with those preterm infants born non-SGA. There were no differences between preterm SGA and preterm non-SGA groups in waist/hip ratio, body fat, body fat per cent, truncal fat per cent, fat mass index or lean mass index, although power was limited for some analyses. Studies were rated at high risk of bias due to potential residual confounding and low risk of bias in other domains. CONCLUSIONS: Compared to their preterm non-SGA peers, preterm infants born SGA have lower BMI, waist circumference, lean body mass and height in later life. No differences in adiposity were observed between SGA preterm infants and non-SGA preterm infants.

Association of postpartum medication practices with early breastfeeding cessation among mothers with chronic conditions: A prospective cohort study.

INTRODUCTION: Use of medications is a common concern for breastfeeding women, particularly when they are strongly needed or unavoidable to manage maternal chronic conditions. Yet the influence of medication usage patterns on breastfeeding duration in mothers with chronic conditions is unclear. The objective of this study was to examine whether postpartum medication practices were associated with shorter breastfeeding duration or earlier than planned breastfeeding cessation among mothers with chronic conditions. MATERIAL AND METHODS: We analyzed 346 mothers with chronic conditions enrolled in a prospective, community-based pregnancy cohort study (Alberta, Canada) who initiated breastfeeding after birth. Data were collected through self-report questionnaires spanning late pregnancy to 6 months postpartum. Based on reported use of preexisting medications while breastfeeding, women were classified as continuing medications (reference group), discontinuing one or more medications, or those who did not use preexisting medications. Cox proportional hazards regression was used to analyze the association of medication practices and overall breastfeeding duration in weeks. Logistic regression was used to analyze the association of medication practices and earlier than planned breastfeeding cessation. Multivariable models adjusted for demographic and health-related factors. RESULTS: Overall, 30.6% of women with chronic conditions stopped breastfeeding in the first 6 months, almost all of whom did so earlier than planned. In multivariable models, medication discontinuation was significantly associated with shorter breastfeeding duration (adjusted hazard ratio [HR] 1.67, 95% confidence interval [CI] 1.03-2.70) and earlier than planned breastfeeding cessation (adjusted odds ratio [OR] 1.85, 95% CI 1.01-3.42), whereas medication non-use was not associated with differences in breastfeeding outcomes. CONCLUSIONS: Women with chronic conditions who discontinued preexisting medications while breastfeeding had significantly shorter breastfeeding duration and were less likely to meet their breastfeeding goals in the first 6 months postpartum compared to women who continued preexisting medications.

Breastfeeding difficulties in the first 6 weeks postpartum among mothers with chronic conditions: a latent class analysis.

BACKGROUND: Breastfeeding difficulties frequently exacerbate one another and are common reasons for curtailed breastfeeding. Women with chronic conditions are at high risk of early breastfeeding cessation, yet limited evidence exists on the breastfeeding difficulties that co-occur in these mothers. The objective of this study was to explore clusters of breastfeeding difficulties experienced up to 6 weeks postpartum among mothers with chronic conditions and to examine associations between chronic condition types and breastfeeding difficulty clusters. METHODS: We analyzed 348 mothers with chronic conditions enrolled in a prospective, community-based pregnancy cohort study from Alberta, Canada. Data were collected through self-report questionnaires. We used latent class analysis to identify clusters of early breastfeeding difficulties and multinomial logistic regression to examine whether types of chronic conditions were associated with these clusters, adjusting for maternal and obstetric factors. RESULTS: We identified three clusters of breastfeeding difficulties. The "physiologically expected" cluster (51.1% of women) was characterized by leaking breasts and engorgement (reference outcome group); the "low milk production" cluster (15.4%) was discerned by low milk supply and infant weight concerns; and the "ineffective latch" cluster (33.5%) involved latch problems, sore nipples, and difficulty with positioning. Endocrine (adjusted relative risk ratio [RRR] 2.34, 95% CI 1.10-5.00), cardiovascular (adjusted RRR 2.75, 95% CI 1.01-7.81), and gastrointestinal (adjusted RRR 2.51, 95% CI 1.11-5.69) conditions were associated with the low milk production cluster, and gastrointestinal (adjusted RRR 2.44, 95% CI 1.25-4.77) conditions were additionally associated with the ineffective latch cluster. CONCLUSION: Half of women with chronic conditions experienced clusters of breastfeeding difficulties corresponding either to low milk production or to ineffective latch in the first 6 weeks postpartum. Associations with chronic condition types suggest that connections between lactation physiology and disease pathophysiology should be considered when providing breastfeeding support.

Association between childhood adversities and premature and potentially avoidable mortality in adulthood: a population-based study.

BACKGROUND: The association of childhood adversities with mortality has rarely been explored, and even less studied is the question of whether any excess mortality may be potentially preventable. This study examined the association between specific childhood adversities and premature and potentially avoidable mortality (PPAM) in adulthood in a representative sample of the general population. Also, we examined whether the associations were potentially mediated by various adult socioeconomic, psychosocial, and behavioral factors. METHODS: The study used data from the National Population Health Survey (NPHS-1994) linked to the Canadian Vital Statistics Database (CVSD 1994-2014) available from Statistics Canada. The NPHS interview retrospectively assessed childhood exposure to prolonged hospitalization, parental divorce, prolonged parental unemployment, prolonged trauma, parental problematic substance use, physical abuse, and being sent away from home for doing something wrong. An existing definition of PPAM, consisting of causes of death considered preventable or treatable before age 75, was used. Competing cause survival models were used to examine the associations of specific childhood adversities with PPAM in adulthood among respondents aged 18 to 74 years (rounded n = 11,035). RESULTS: During the 20-year follow-up, 5.4% of the sample died prematurely of a cause that was considered potentially avoidable. Childhood adversities had a differential effect on mortality. Physical abuse (age-adjusted sub-hazard ratio; SHR 1.44; 95% CI 1.03, 2.00) and being sent away from home (age-adjusted SHR 2.26; 95% CI 1.43,3.57) were significantly associated with PPAM. The associations were attenuated when adjusted for adulthood factors, namely smoking, poor perceived health, depression, low perceived social support, and low income, consistent with possible mediating effects. Other adversities under study were not associated with PPAM. CONCLUSION: The findings imply that the psychological sequelae of childhood physical abuse and being sent away from home and subsequent uptake of adverse health behavior may lead to increased risk of potentially avoidable mortality. The potential mediators identified offer directions for future research to perform causal mediation analyses with suitable data and identify interventions aimed at preventing premature mortality due to potentially avoidable causes. Other forms of adversities, mostly related to household dysfunction, may not be determinants of the distal health outcome of mortality.

Can the adverse childhood experiences (ACEs) checklist be utilized to predict emergency department visits among children and adolescents?

BACKGROUND: Extensive literature has shown an association of Adverse Childhood Experiences (ACEs) with adverse health outcomes; however, its ability to predict events or stratify risks is less known. Individuals with mental illness and ACE exposure have been shown to visit emergency departments (ED) more often than those in the general population. This study thus examined the ability of the ACEs checklist to predict ED visits within the subsequent year among children and adolescents presenting to mental health clinics with pre-existing mental health issues. METHODS: The study analyzed linked data (n = 6100) from two databases provided by Alberta Health Services (AHS). The Regional Access and Intake System (RAIS 2016-2018) database provided data on the predictors (ACE items, age, sex, residence, mental health program type, and primary diagnosis) regarding children and adolescents (aged 0-17 years) accessing addiction and mental health services within Calgary Zone, and the National Ambulatory Care Reporting System (NACRS 2016-2019) database provided data on ED visits. A 25% random sample of the data was reserved for validation purposes. Two Least Absolute Shrinkage and Selection Operator (LASSO) logistic regression models, each employing a different method to tune the shrinkage parameter lambda (namely cross-validated and adaptive) and performing 10-fold cross-validation for a set of 100 lambdas in each model were examined. RESULTS: The adaptive LASSO model had a slightly better fit in the validation dataset than the cross-validated model; however, it still demonstrated poor discrimination (AUC 0.60, sensitivity 37.8%, PPV 49.6%) and poor calibration (over-triaged in low-risk and under-triaged in high-risk subgroups). The model's poor performance was evident from an out-of-sample deviance ratio of - 0.044. CONCLUSION: The ACEs checklist did not perform well in predicting ED visits among children and adolescents with existing mental health concerns. The diverse causes of ED visits may have hindered accurate predictions, requiring more advanced statistical procedures. Future studies exploring other machine learning approaches and including a more extensive set of childhood adversities and other important predictors may produce better predictions. Furthermore, despite highly significant associations being observed, ACEs may not be deterministic in predicting health-related events at the individual level, such as general ED use.

Developmental Pathways Between Infant Gestures and Symbolic Actions, and Children's Communicative Skills at Age 5: Findings From the All Our Families Pregnancy Cohort.

Using data from the All Our Families study, a longitudinal study of 1992 mother-child dyads in Canada (47.7% female; 81.9% White), we examined the developmental pathways between infant gestures and symbolic actions and communicative skills at age 5. Communicative gestures at age 12 months (e.g., pointing, nodding head "yes"), obtained via parental report, predicted stronger general communicative skills at age 5 years. Moreover, greater use of symbolic actions (e.g., "feeding" a stuffed animal with a bottle) indirectly predicted increased communicative skills at age 5 via increased productive vocabulary at 24 months. These pathways support the hypothesis that children's communicative skills during the transition to kindergarten emerge from a chain of developmental abilities starting with gestures and symbolic actions during infancy.

Adverse childhood experiences are associated with illicit drug use among pregnant women with middle to high socioeconomic status: findings from the All Our Families Cohort.

BACKGROUND: Adverse childhood experiences (ACEs) are associated with illicit drug use among pregnant women who are socioeconomically vulnerable. While it is assumed that the impact of ACEs on illicit drug use in pregnancy is reduced among women with higher socioeconomic status (SES), this assumption is not well tested in the literature. The objective of this study was to examine the impact of maternal ACEs on illicit drug use in a community-based sample of pregnant women with middle to high SES. METHODS: This study is a secondary analysis of a prospective cohort study that collected data from 1660 women during and after pregnancy in Calgary, Canada between 2008 and 2011 using mailed surveys. Illicit drug use in pregnancy was self-reported by women at 34-36 weeks gestation. An established scale examined maternal ACEs before 18 years. Logistic regression models and 95% confidence intervals tested associations between maternal ACE scores and illicit drug use in pregnancy. RESULTS: Overall, 3.1% of women in this predominantly married, well-educated, middle and upper middle income sample reported illicit drug use in pregnancy. Women with 2-3 ACEs had more than a two-fold increase, and women with 4 or more ACEs had almost a four-fold increase in illicit drug use in pregnancy, relative to women with 0-1 ACEs after adjustment for confounders. Exposure to child abuse was more consistently associated with illicit drug use in pregnancy than exposure to household dysfunction in childhood. CONCLUSIONS: Maternal ACEs were common and associated with a moderate increase in the odds of illicit drug use in pregnancy among Canadian women with middle to high SES.

Pregnancy complications and risk of preterm birth according to maternal age: A population-based study of delivery hospitalizations in Alberta.

INTRODUCTION: Pregnancy-related medical complications are associated with a 2- to 5-fold increased risk of preterm birth (PTB), but the nature of this etiologic relation in context with maternal factors remains poorly understood. Previous studies have generally treated maternal age as a confounder but overlooked its potential as an effect modifier, whereby the magnitude of the effect of complications on PTB could differ significantly across age groups. We investigated whether advanced maternal age (≥35 years) modified the association between pregnancy complications and PTB, and compared population-attributable fractions of PTB from complications in women older vs younger than 35 years. MATERIAL AND METHODS: We analyzed population-based, cross-sectional data from the Alberta Discharge Abstract Database for women aged 18-50 years with singleton live births in hospital between 2014 and 2017 (n = 152 246). Complications were preeclampsia, gestational diabetes, and placental disorders identified using diagnostic codes. Outcomes were spontaneous (sPTB) or iatrogenic (iPTB) PTB before 37 weeks of gestation. We estimated risk ratios and risk differences using modified Poisson and log binomial regression, respectively, adjusting for confounders (pregnancy history, comorbidities). Population-attributable fractions estimates were calculated from risk ratios. Age modification was tested using interaction terms and Z-tests. RESULTS: Prevalence of advanced maternal age was 19.2%. Pregnancy complications and s/iPTB were more common among women aged ≥35 years. Age modified the risk of PTB from preeclampsia only, with risk differences of 9.9% (95% CI 7.2%-12.6%) in older women vs 6.1% (95% CI 4.8%-7.4%) in younger women (P-interaction = 0.012) for sPTB, and 29.5% (95% CI 26.0%-33.1%) vs 20.8% (95% CI 18.9%-22.6%, P-interaction <0.001) for iPTB. Population-attributable fractions of s/iPTB types for all complications were consistently 2%-5% larger in women aged ≥35 years, and significantly larger for preeclampsia (sPTB: 5.1% vs 2.7%, P = 0.002; iPTB: 18.8% vs 14.0%, P < 0.001) and placental disorders (sPTB: 12.5% vs 8.7%, P < 0.001; iPTB: 13.2% vs 8.9%, P < 0.001). CONCLUSIONS: Of the pregnancy complications studied, advanced maternal age only modified the association between PTB and preeclampsia, such that older women with preeclampsia have a higher risk for s/iPTB than younger counterparts. Pregnancy complications contribute to a sizable proportion of PTBs in Alberta, especially among women aged ≥35 years. Findings may inform clinical risk assessment and population-level policy targeting PTB.

Hypertensive Disorders of Pregnancy and Symptoms of Depression and Anxiety as Related to Gestational Age at Birth: Findings From the All Our Families Study.

OBJECTIVE: The aim of the study was to investigate whether symptoms of depression or state anxiety changed the strength or nature of the association between hypertensive disorders of pregnancy (HDP) and gestational age at birth. METHODS: We conducted a secondary analysis of data from the All Our Families Cohort, a prospective pregnancy cohort study based in Calgary, Alberta, Canada. Self-reported depressive symptoms and state anxiety were assessed between 3 and 5 months of gestation, and obstetrical information, including diagnosis of HDP, parity, type of delivery, and gestational age at birth, was retrieved from the maternal discharge abstract. All models were adjusted for sociodemographic and obstetric confounders. RESULTS: Of 2763 women who had a singleton pregnancy and live birth, 247 (9%) were diagnosed with HDP. Women with HDP had significantly shorter gestational length relative to those without the diagnosis (M = 37.87 versus M = 38.99 weeks of gestation), t(2761) = 9.43, p < .001. Moderation analyses showed significant HDP by depressive symptoms and HDP by state anxiety interactions, such that the strength of the association between HDP and gestational age at birth increased alongside greater depressive symptom and state anxiety severity. CONCLUSIONS: Results suggest that depressive symptoms and state anxiety may add to the increased risk for shortened gestation associated with HDP. Women at high risk of cardiovascular complications during pregnancy may benefit from additional resources to manage symptoms of depression or anxiety.

Sharing longitudinal, non-biological birth cohort data: a cross-sectional analysis of parent consent preferences.

BACKGROUND: Mandates abound to share publicly-funded research data for reuse, while data platforms continue to emerge to facilitate such reuse. Birth cohorts (BC) involve longitudinal designs, significant sample sizes and rich and deep datasets. Data sharing benefits include more analyses, greater research complexity, increased opportunities for collaboration, amplification of public contributions, and reduced respondent burdens. Sharing BC data involves significant challenges including consent, privacy, access policies, communication, and vulnerability of the child. Research on these issues is available for biological data, but these findings may not extend to BC data. We lack consensus on how best to approach these challenges in consent, privacy, communication and autonomy when sharing BC data. We require more stakeholder engagement to understand perspectives and generate consensus. METHODS: Parents participating in longitudinal birth cohorts completed a web-based survey investigating consent preferences for sharing their, and their child's, non-biological research data. Results from a previous qualitative inquiry informed survey development, and cognitive interviewing methods (n = 9) were used to improve the question quality and comprehension. Recruitment was via personalized email, with email and phone reminders during the 14-day window for survey completion. RESULTS: Three hundred and forty-six of 569 parents completed the survey in September 2014 (60.8%). Participants preferred consent processes for data sharing in future independent research that were less-active (i.e. no consent or opt-out). Parents' consent preferences are associated with their communication preferences. Twenty percent (20.2%) of parents generally agreed that their child should provide consent to continue participating in research at age 12, while 25.6% felt decision-making on sharing non-biological research data should begin at age 18. CONCLUSIONS: These finding reflect the parenting population's preference for less project-specific permission when research data is non-biological and de-identified and when governance practices are highly detailed and rigourous. Parents recognize that children should become involved in consent for secondary data use, but there is variability regarding when and how involvement occurs. These findings emphasize governance processes and participant notification rather than project-specific consent for secondary use of de-identified, non-biological data. Ultimately, parents prefer general consent processes for sharing de-identified, non-biological research data with ultimate involvement of the child.

Recall of Prenatal Counselling Among Obese and Overweight Women from a Canadian Population: A Population Based Study.

Objective The objective of this study was to evaluate the recall of prenatal counselling received among overweight and obese women in primary care settings. Methods A sample of 1996 women with singleton, term deliveries and pre-pregnancy BMI >18.5 kg/m2 were identified from the All Our Babies pregnancy cohort. Information on socio-demographic characteristics and women's experiences with prenatal counselling on nutrition, vitamin and mineral supplements, exercise, weight gain, employment, alcohol and drug use, and smoking during pregnancy were collected through questionnaires administered at <25 weeks and 34-36 weeks gestation. Multivariable logistic regression analyses explored the associations between pre-pregnancy BMI and the domains of prenatal counselling, controlling for confounders. Results Women reported high levels of comfort asking questions and satisfaction with their health care provider. Women reported getting information about nutrition (69.3%), weight gain (67.8%), exercise (64.4%), vitamins and minerals supplementation (86.1%). Obese women (211, 10.6%) were more likely than normal weight women (1313, 65.8%) to be Caucasian (p = 0.004), less educated (p = 0.001), and to have been born or lived in Canada for at least 5 years (p = 0.01). There was no difference in the prenatal advice received on nutrition, weight gain and exercise in pregnancy between obese, overweight, and normal weight women. Conclusions for Practice Pre-pregnancy BMI did not appear to influence the recall of prenatal counselling women receive in community health care centers. Given the importance of nutrition and weight gain during pregnancy, and guidelines for weight gain based on pre-pregnancy BMI, there are missed opportunities in knowledge exchange between women and providers in the prenatal period.

The impact of caesarean section on breastfeeding initiation, duration and difficulties in the first four months postpartum.

BACKGROUND: The caesarean section (c-section) rate in Canada is 27.1%, well above the 5-15% of deliveries suggested by the World Health Organization in 2009. Emergency and planned c-sections may adversely affect breastfeeding initiation, milk supply and infant breastfeeding receptivity compared to vaginal deliveries. Our study examined mode of delivery and breastfeeding initiation, duration, and difficulties reported by mothers at 4 months postpartum. METHODS: The All Our Babies study is a prospective pregnancy cohort in Calgary, Alberta, that began in 2008. Participants completed questionnaires at <25 and 34-36 weeks gestation and approximately 4 months postpartum. Demographic, mental health, lifestyle, and health services data were obtained. Women giving birth to singleton infants were included (n = 3021). Breastfeeding rates and difficulties according to mode of birth (vaginal, planned c-section and emergency c-section) were compared using cross-tabulations and chi-square tests. A multivariable logistic regression model was created to examine the association between mode of birth on breastfeeding duration to 12 weeks postpartum. RESULTS: More women who delivered by planned c-section had no intention to breastfeed or did not initiate breastfeeding (7.4% and 4.3% respectively), when compared to women with vaginal births (3.4% and 1.8%, respectively) and emergency c-section (2.7% and 2.5%, respectively). Women who delivered by emergency c-section were found to have a higher proportion of breastfeeding difficulties (41%), and used more resources before (67%) and after (58%) leaving the hospital, when compared to vaginal delivery (29%, 40%, and 52%, respectively) or planned c-sections (33%, 49%, and 41%, respectively). Women who delivered with a planned c-section were more likely (OR = 1.61; 95% CI: 1.14, 2.26; p = 0.014) to discontinue breastfeeding before 12 weeks postpartum compared to those who delivered vaginally, controlling for income, education, parity, preterm birth, maternal physical and mental health, ethnicity and breastfeeding difficulties. CONCLUSIONS: We found that when controlling for socio-demographic and labor and delivery characteristics, planned c-section is associated with early breastfeeding cessation. Anticipatory guidance around breastfeeding could be provided to women considering a planned c-section. As well, additional supportive care could be made available to lactating women with emergency c-sections, within the first 24 hours post birth and throughout the early postpartum period.

Who is distressed? A comparison of psychosocial stress in pregnancy across seven ethnicities.

BACKGROUND: Calgary, Alberta has the fourth highest immigrant population in Canada and ethnic minorities comprise 28 % of its total population. Previous studies have found correlations between minority status and poor pregnancy outcomes. One explanation for this phenomenon is that minority status increases the levels of stress experienced during pregnancy. The aim of the present study was to identify specific types of maternal psychosocial stress experienced by women of an ethnic minority (Asian, Arab, Other Asian, African, First Nations and Latin American). METHODS: A secondary analysis of variables that may contribute to maternal psychosocial stress was conducted using data from the All Our Babies prospective pregnancy cohort (N = 3,552) where questionnaires were completed at < 24 weeks of gestation and between 34 and 36 weeks of gestation. Questionnaires included standardized measures of perceived stress, anxiety, depression, physical and emotional health, and social support. Socio-demographic data included immigration status, language proficiency in English, ethnicity, age, and socio-economic status. RESULTS: Findings from this study indicate that women who identify with an ethnic minority were more likely to report symptoms of depression, anxiety, inadequate social support, and problems with emotional and physical health during pregnancy than women who identified with the White reference group. CONCLUSIONS: This study has identified that women of an ethic minority experience greater psychosocial stress in pregnancy compared to the White reference group.

Exploring the relationship between socioeconomic factors, method of contraception and unintended pregnancy.

BACKGROUND: It is estimated that approximately one-third of pregnancies in Canada are unintended, meaning they were either mistimed (the woman wanted to be pregnant at a different point in time) or undesired (the woman did not want to be pregnant). This study aimed to assess the impact of socioeconomic variables and method of contraception on the decision to either terminate or continue and unintended pregnancy. METHODS: Data were obtained from two contemporaneous studies in Calgary Canada--a cross-sectional study involving women seeking abortion services (n = 577) and a longitudinal cohort study involving women with continuing pregnancies (n = 3552) between 2008 and 2012. Chi square tests and logistic regression were used to examine the association between socioeconomic variables, use of contraception and pregnancy intention. RESULTS: 96.5% of women seeking an abortion and 19.6% of women with ongoing pregnancies reported having an unintended pregnancy. Women with unintended pregnancies were significantly younger (p < 0.001), less educated (p < 0.001), had a lower household income (p < 0.001), were less likely to be in a stable relationship (p < 0.001), and less likely to speak English in the home (p < 0.002). 20.2% reported not using any form of birth control despite their desire to not get pregnant. Among women with unintended pregnancies, the only significant demographic predictor of not using any form of contraception was low educational attainment (OR = 1.7, 95% CI: 1.2-2.4). CONCLUSIONS: Low educational attainment was associated with not using any form of contraception among women with unintended pregnancies. However, as unintended pregnancy occurs across all socio-demographic groups, care providers are encouraged to have an open discussion regarding fertility goals and contraception with all patients and refer them to appropriate resource materials.

Preterm Birth and Social Support during Pregnancy: a Systematic Review and Meta-Analysis.

BACKGROUND: Additional social support is often recommended for women during the prenatal period to optimise birth outcomes, specifically to avoid preterm birth. Social support is thought to act in one of two ways: by reducing stress and anxiety, or by providing coping mechanisms for women with high stress. However, evidence in this area is mixed. The purpose of this meta-analysis is to determine if low levels of social support are associated with an increased risk for preterm birth. METHODS: Six databases were searched for randomised control trials and cohort studies regarding social support and preterm birth with no limits set on date or language. Inclusion criteria included the use of a validated instrument to measure social support, and studies conducted in high-income or high-middle-income countries. RESULTS: There were 3467 records retrieved, 16 of which met the inclusion criteria. Eight studies (n = 14 630 subjects) demonstrated a pooled odds ratio (OR) of 1.22 (95% CI 0.84, 1.76) for preterm birth in women with low social support compared with high social support. Among women with high stress levels, two studies (n = 6374 subjects) yielded a pooled OR of 1.52 (95% CI 1.18, 1.97). The results of six studies could not be pooled due to incompatibility of outcome measures. CONCLUSIONS: There is no evidence for a direct association between social support and preterm birth. Social support, however, may provide a buffering mechanism between stress and preterm birth.

Contribution of prepregnancy body mass index and gestational weight gain to adverse neonatal outcomes: population attributable fractions for Canada.

BACKGROUND: Low or high prepregnancy body mass index (BMI) and inadequate or excess gestational weight gain (GWG) are associated with adverse neonatal outcomes. This study estimates the contribution of these risk factors to preterm births (PTBs), small-for-gestational age (SGA) and large-for-gestational age (LGA) births in Canada compared to the contribution of prenatal smoking, a recognized perinatal risk factor. METHODS: We analyzed data from the Canadian Maternity Experiences Survey. A sample of 5,930 women who had a singleton live birth in 2005-2006 was weighted to a nationally representative population of 71,200 women. From adjusted odds ratios, we calculated population attributable fractions to estimate the contribution of BMI, GWG and prenatal smoking to PTB, SGA and LGA infants overall and across four obstetric groups. RESULTS: Overall, 6% of women were underweight (<18.5 kg/m(2)) and 34.4% were overweight or obese (≥25.0 kg/m(2)). More than half (59.4%) gained above the recommended weight for their BMI, 18.6% gained less than the recommended weight and 10.4% smoked prenatally. Excess GWG contributed more to adverse outcomes than BMI, contributing to 18.2% of PTB and 15.9% of LGA. Although the distribution of BMI and GWG was similar across obstetric groups, their impact was greater among primigravid women and multigravid women without a previous PTB or pregnancy loss. The contributions of BMI and GWG to PTB and SGA exceeded that of prenatal smoking. CONCLUSIONS: Maternal weight, and GWG in particular, contributes significantly to the occurrence of adverse neonatal outcomes in Canada. Indeed, this contribution exceeds that of prenatal smoking for PTB and SGA, highlighting its public health importance.