Neighbourhood material deprivation and severe maternal morbidity: a population-based cohort study in Ontario, Canada.

OBJECTIVES: Rates of age-associated severe maternal morbidity (SMM) have increased in Canada, and an association with neighbourhood income is well established. Our aim was to examine SMM trends according to neighbourhood material deprivation quintile, and to assess whether neighbourhood deprivation effects are moderated by maternal age. DESIGN, SETTING AND PARTICIPANTS: A population-based retrospective cohort study using linked administrative databases in Ontario, Canada. We included primiparous women with a live birth or stillbirth at ≥20 weeks' gestational age. PRIMARY OUTCOME: SMM from pregnancy onset to 42 days postpartum. We calculated SMM rate differences (RD) and rate ratios (RR) by neighbourhood material deprivation quintile for each of four 4-year cohorts from 1 April 2002 to 31 March 2018. Log-binomial multivariable regression adjusted for maternal age, demographic and pregnancy-related variables. RESULTS: There were 1 048 845 primiparous births during the study period. The overall rate of SMM was 18.0 per 1000 births. SMM rates were elevated for women living in areas with high material deprivation. In the final 4-year cohort, the RD between women living in high vs low deprivation neighbourhoods was 3.91 SMM cases per 1000 births (95% CI: 2.12 to 5.70). This was higher than the difference observed during the first 4-year cohort (RD 2.09, 95% CI: 0.62 to 3.56). SMM remained associated with neighbourhood material deprivation following multivariable adjustment in the pooled sample (RR 1.16, 95% CI: 1.11 to 1.21). There was no evidence of interaction with maternal age. CONCLUSION: SMM rate increases were more pronounced for primiparous women living in neighbourhoods with high material deprivation compared with those living in low deprivation areas. This raises concerns of a widening social gap in maternal health disparities and highlights an opportunity to focus risk reduction efforts toward disadvantaged women during pregnancy and postpartum.

Association of Maternal Influenza Vaccination During Pregnancy With Early Childhood Health Outcomes.

Importance: Seasonal influenza vaccination in pregnancy can reduce influenza illness among pregnant women and newborns. Evidence is limited on whether seasonal influenza vaccination in pregnancy is associated with adverse childhood health outcomes. Objective: To assess the association between maternal influenza vaccination during pregnancy and early childhood health outcomes. Design, Setting, and Participants: Retrospective cohort study, using a birth registry linked with health administrative data. All live births in Nova Scotia, Canada, between October 1, 2010, and March 31, 2014, were included, with follow-up until March 31, 2016. Adjusted hazard ratios (HRs) and incidence rate ratios (IRRs) with 95% confidence intervals were estimated while controlling for maternal medical history and other potential confounders using inverse probability of treatment weighting. Exposures: Seasonal influenza vaccination during pregnancy. Main Outcomes and Measures: Childhood outcomes studied were immune-related (eg, asthma, infections), non-immune-related (eg, neoplasms, sensory impairment), and nonspecific (eg, urgent or inpatient health care utilization), measured from emergency department and hospitalization databases. Results: Among 28 255 children (49% female, 92% born at ≥37 weeks' gestation), 10 227 (36.2%) were born to women who received seasonal influenza vaccination during pregnancy. During a mean follow-up of 3.6 years, there was no significant association between maternal influenza vaccination and childhood asthma (incidence rate, 3.0 vs 2.5 per 1000 person-years; difference, 0.53 per 1000 person-years [95% CI, -0.15 to 1.21]; adjusted HR, 1.22 [95% CI, 0.94 to 1.59]), neoplasms (0.32 vs 0.26 per 1000 person-years; difference, 0.06 per 1000 person-years [95% CI, -0.16 to 0.28]; adjusted HR, 1.26 [95% CI, 0.57 to 2.78]), or sensory impairment (0.80 vs 0.97 per 1000 person-years; difference, -0.17 per 1000 person-years [95% CI, -0.54 to 0.21]; adjusted HR, 0.82 [95% CI, 0.49 to 1.37]). Maternal influenza vaccination in pregnancy was not significantly associated with infections in early childhood (incidence rate, 184.6 vs 179.1 per 1000 person-years; difference, 5.44 per 1000 person-years [95% CI, 0.01 to 10.9]; adjusted IRR, 1.07 [95% CI, 0.99 to 1.15]) or with urgent and inpatient health services utilization (511.7 vs 477.8 per 1000 person-years; difference, 33.9 per 1000 person-years [95% CI, 24.9 to 42.9]; adjusted IRR, 1.05 [95% CI, 0.99 to 1.16]). Conclusions and Relevance: In this population-based cohort study with mean follow-up duration of 3.6 years, maternal influenza vaccination during pregnancy was not significantly associated with an increased risk of adverse early childhood health outcomes.

Racial/ethnic variations in gestational weight gain: a population-based study in Ontario.

OBJECTIVE: To explore inadequate and excessive gestational weight gain (GWG) among pregnant women of different racial/ethnic backgrounds in Ontario, Canada. METHODS: A population-based retrospective cohort study was conducted among women who had prenatal screening and had a singleton birth in an Ontario hospital between April 2016 and March 2017. We estimated adjusted risk ratios (aRR) of racial/ethnic differences for inadequate or excessive GWG using multinomial logistic regression models. Interaction effects were examined to determine whether racial/ethnic difference in GWG varied by pre-pregnancy body mass index (BMI). RESULTS: Among 74,424 women, the prevalence of inadequate GWG in White, Asian, and Black women was 15.7%, 25.8%, and 25.0%, and excessive GWG was 62.8%, 45.5%, and 54.7%, respectively. There were significant interaction effects between race/ethnicity and pre-pregnancy BMI for inadequate GWG (Wald p < 0.01) and excessive GWG (Wald p < 0.01). Compared with White women, Asian women had higher risk of inadequate GWG and lower risk of excessive GWG in all weight classes, and Black women had higher risk of inadequate GWG and lower risk of excessive GWG if their BMI was normal, overweight, or obese. CONCLUSION: Variations in unhealthy GWG by pre-pregnancy weight classes among Ontario White, Asian and Black women were observed. Individualized counseling regarding appropriate GWG is universally recommended. Additional consideration of racial/ethnic variations by maternal weight classes may help to promote healthy GWG in Canada.

Agreement assessment of key maternal and newborn data elements between birth registry and Clinical Administrative Hospital Databases in Ontario, Canada.

PURPOSE: Since 2012, BORN Ontario, a maternal-newborn registry, has collected data on every birth in Ontario. To ensure data quality, we assessed the reliability of key elements collected in BORN by comparing these with like data elements in the Canadian Institute for Health Information-Discharge Abstract Database (CIHI-DAD). METHODS: We used provincial health card numbers to deterministically link live or stillbirth records and their corresponding mothers' records in the BORN database to the CIHI-DAD in the fiscal years 2012-2013 to 2014-2015. Percentage agreement and Cohen Kappa statistics were used to assess agreement on main elements in both databases. RESULTS: The percentage agreement and Kappa coefficients were 99.98% and 0.740 (95% CI: 0.677-0.803) on live/stillbirth, respectively. The Kappa coefficients for infant sex, gestational age at birth, induction of labour, and caesarean birth were 0.989 (95% CI: 0.988-0.989), 0.920 (95% CI: 0.919-0.920), 0.782 (95% CI: 0.780-0.785), and 0.995 (95% CI: 0.995-0.996), respectively. Kappa agreement for the number of fetuses in a pregnancy was 0.979 (95% CI: 0.977-0.981). Percentage agreement was very high for infants' birthdates (99.9%), infant postal codes (91.8%), infants' birth weight in grams (95.5%), and mothers' dates of birth (99.1%). CONCLUSIONS: Overall, the BORN and CIHI-DAD databases had concordance on key birth and maternal data elements; however, additional work is needed to understand discrepancies identified.

The health system impact of false positive newborn screening results for medium-chain acyl-CoA dehydrogenase deficiency: a cohort study.

BACKGROUND: There is no consensus in the literature regarding the impact of false positive newborn screening results on early health care utilization patterns. We evaluated the impact of false positive newborn screening results for medium-chain acyl-CoA dehydrogenase deficiency (MCADD) in a cohort of Ontario infants. METHODS: The cohort included all children who received newborn screening in Ontario between April 1, 2006 and March 31, 2010. Newborn screening and diagnostic confirmation results were linked to province-wide health care administrative datasets covering physician visits, emergency department visits, and inpatient hospitalizations, to determine health service utilization from April 1, 2006 through March 31, 2012. Incidence rate ratios (IRRs) were used to compare those with false positive results for MCADD to those with negative newborn screening results, stratified by age at service use. RESULTS: We identified 43 infants with a false positive newborn screening result for MCADD during the study period. These infants experienced significantly higher rates of physician visits (IRR: 1.42) and hospitalizations (IRR: 2.32) in the first year of life relative to a screen negative cohort in adjusted analyses. Differences in health services use were not observed after the first year of life. CONCLUSIONS: The higher use of some health services among false positive infants during the first year of life may be explained by a psychosocial impact of false positive results on parental perceptions of infant health, and/or by differences in underlying health status. Understanding the impact of false positive newborn screening results can help to inform newborn screening programs in designing support and education for families. This is particularly important as additional disorders are added to expanded screening panels, yielding important clinical benefits for affected children but also a higher frequency of false positive findings.

Socioeconomic position and factors associated with use of a nonsupine infant sleep position: findings from the Canadian Maternity Experiences Survey.

OBJECTIVES: With a focus on socioeconomic position, we examined the association between maternal education and nonsupine infant sleep position, and examined patterns of effect modification with additional sociodemographic, maternal, infant, and health services predictors. METHODS: Data were from the Maternity Experiences Survey, a national population-based sample of 76 178 new Canadian mothers (unweighted n = 6421) aged 15 years or older interviewed in 2006-2007. Using logistic regression, we developed multivariate models for 3 maternal education strata. RESULTS: Level of maternal education was significantly and inversely related to nonsupine infant sleep position. Stratified analyses revealed different predictive factors for nonsupine infant sleep position across strata of maternal education. Postpartum home visits were not associated with use of this sleep position among new mothers with less than high school completion. Adequacy of postpartum information regarding sudden infant death syndrome was not associated with nonsupine infant sleep position in any of the educational strata. CONCLUSIONS: These findings suggest a need to revisit Back to Sleep health promotion strategies and to ensure that these interventions are tailored to match the information needs of all families, including mothers with lower levels of formal education.

Measuring quality in maternal-newborn care: developing a clinical dashboard.

Pregnancy, birth, and the early newborn period are times of high use of health care services. As well as opportunities for providing quality care, there are potential missed opportunities for health promotion, safety issues, and increased costs for the individual and the system when quality is not well defined or measured. There has been a need to identify key performance indicators (KPIs) to measure quality care within the provincial maternal-newborn system. We also wanted to provide automated audit and feedback about these KPIs to support quality improvement initiatives in a large Canadian province with approximately 140 000 births per year. We therefore worked to develop a maternal-newborn dashboard to increase awareness about selected KPIs and to inform and support hospitals and care providers about areas for quality improvement. We mapped maternal-newborn data elements to a quality domain framework, sought feedback via survey for the relevance and feasibility of change, and examined current data and the literature to assist in setting provincial benchmarks. Six clinical performance indicators of maternal-newborn quality care were identified and evidence-informed benchmarks were set. A maternal-newborn dashboard with "drill down" capacity for detailed analysis to enhance audit and feedback is now available for implementation. While audit and feedback does not guarantee individuals or institutions will make practice changes and move towards quality improvement, it is an important first step. Practice change and quality improvement will not occur without an awareness of the issues.

The impact of pregnancy on physical activity level.

OBJECTIVE: The purpose of this study was to compare women's levels of physical activity during early pregnancy and during the year before pregnancy, and to identify characteristics associated with discontinuing sports and exercise among women previously active during the year before pregnancy. METHODS: Data collected from 1,737 women enrolled in a prospective cohort study and who had no contraindications for exercise were included in this analysis. Measures of physical activity (including household and care-giving activities, active living and sports and exercise activities) during early pregnancy were compared to the year before pregnancy. Log binomial regression was used to identify factors associated with discontinuing sports and exercise during pregnancy. RESULTS: There was a statistically significant decrease in all summary measures of physical activity during early pregnancy. The largest decreases were observed in sports and exercise activity. Among women active before pregnancy, age <35 years, multiparity, less than university education, pre-pregnancy body mass index (BMI) > or = 30 kg/m(2) and lower levels of pre-pregnancy exercise were associated with discontinuing sports and exercise activities during pregnancy. CONCLUSION: Most women reduced their physical activity level during the first 20 weeks of pregnancy compared with their level of activity during the year prior to pregnancy, particularly for sports and exercise, although a small proportion of women in this study actually increased their activity in this area during early pregnancy. Participation in sports and exercise activity during pregnancy is potentially modifiable and could favorably impact perinatal health and maternal post-partum weight. The results of this study suggests that pregnancy is an event that leads to a decrease in physical activity.

Residential mobility during pregnancy.

In epidemiological studies of environmental exposures and adverse pregnancy outcomes, maternal residence at delivery is often used to assign an exposure level, based on routinely collected data. In order to examine the potential for exposure misclassification due to residential mobility, we examined maternal mobility according to changes in residence overall, as well as changes in municipality and county. The potential for mobility to be related to pregnancy outcomes was considered by examining the relationship between mobility and risk factors commonly included in investigations of adverse pregnancy outcomes. Previously collected data were studied from 398 population-based control subjects from a case-control study of stillbirths. We compared demographic, lifestyle, medical, pregnancy and environmental factors of women who moved during pregnancy with those who did not. Bivariable and multivariable log binomial regressions were used to identify risk factors that were associated with mobility during pregnancy. Twelve per cent of subjects moved at least once during their pregnancy. Among women who moved, the majority (62%) moved within the same municipality. In bivariable analyses, we found that low family income, lower maternal age, unmarried status and tobacco use were associated with an increased likelihood of moving during pregnancy, whereas women who used folic acid before conception and who had a higher prepregnancy body mass index (BMI) were less likely to move during pregnancy. In multivariable analyses, only family income, age and prepregnancy BMI were independently predictive of mobility. These results indicate that in studies using maternal residence at delivery to assign environmental exposures, mobility during pregnancy is likely to be prevalent enough to introduce exposure misclassification. The potential for differential exposure misclassification should be considered should any of the risk factors for moving identified by this study also be risk factors for the outcome under study.

Exposure assessment in epidemiologic studies of adverse pregnancy outcomes and disinfection byproducts.

A major challenge in studies that examine the association between disinfection byproducts in drinking water and pregnancy outcomes is the accurate representation of a subject's exposure. We used household water samples and questionnaire information on water-use behavior to examine several aspects of exposure assessment: (i) the distribution and correlation of specific disinfection byproducts, (ii) spatial distribution system and temporal variation in byproduct levels, and (iii) the contribution of individual water-use behavior. The level of specific trihalomethanes (THMs) and haloacetic acids (HAAs) was determined for 360 household water samples in Eastern Ontario and Nova Scotia. Subjects were interviewed regarding tap water ingestion and showering and bathing practices. In both provinces, total THMs correlated highly with chloroform (correlation coefficient (r) >0.95) and less so with total HAAs (r = 0.74 in Nova Scotia and r = 0.52 in Ontario). The correlation between total THMs and bromodichloromethane was high in Nova Scotia (r = 0.63), but low in Ontario (r = 0.26). The correlation was between THM level in individual household samples, and the mean THM level during the same time period from several distribution system samples was 0.63, while a higher correlation in THM level was observed for samples taken at the same location 1 year apart (r = 0.87). A correlation of 0.73 was found between household THM level and a total exposure measure incorporating ingestion, showering, and bathing behaviors. These results point to the importance of: measurement of different classes of byproducts; household rather than distribution system sampling; and, incorporation of subject behaviors in exposure assessment in epidemiologic studies of disinfection byproducts and adverse pregnancy outcomes.