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Infant Mortality, Birth Defects and other birth outcomes in Nunavut: The challenge of translating data collection into improved health. Laura Arbour UBC Department of Medical Genetics Uvic Division of Medical Sciences. Understanding adverse birth outcomes in Nunavut.
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Infant Mortality, Birth Defects and other birth outcomes in Nunavut: The challenge of translating data collection into improved health Laura Arbour UBC Department of Medical Genetics Uvic Division of Medical Sciences
Understanding adverse birth outcomes in Nunavut • Understanding the causes of birth defects/heart defects in Nunavut • Understanding whether there is sufficient folic acid fortification in the North to prevent birth defects (and other adverse birth outcomes)-Kait Duncan • Birth outcomes and smoking in Nunavut- Kate Maheffey • Understanding Infant mortality: • Review of causes in infant mortality in Nunavut-Sorcha Collins • CPT1 P479L : What is the prevalence and does it confer risk for infant mortality? Sorcha Collins • Safe Sleep position and breast feeding practices in all Inuit regions (ACS) –Sirisha Asuri -“Qiturngatta –our children”, Sam Lauson
Most children in Nunavut are born healthy! • But when compared by jurisdiction Nunavut has the highest rates of infant mortality, prematurity, low birth weight, birth defects in the country. • Why is that??
Nunavut facts (2006 census) • Became a territory: April 1, 1999 • Population: 29,474 (Inuit 85%) • Land mass: 2 mil sq km (1/5 Canada’s land mass) • Birth rate: 29/1,000 (twice national average) • % population under 25: 60% • About 1/3 of Inuit currently finish high school • Average household income: $31,470 (compared to $45,250) • Cost of living 1.6-3x that of southern Canada • Nearly 30% of income for food (compared to 10% for the rest of Canada)
Nunavut • Primary and tertiary health care delivered through support of three different regional centres (Ottawa, Winnipeg , and Yellowknife/Edmonton) • Public Health mandate is Nunavut alone
Estimated RR for Congenital Anomalies in Inuit infants (to one year) from Baffin Island and Arctic Quebec –the baseline Arbour, Gilpin et al, 2004 IJCH 63(3) 251-265 Based on chart review of 2567 live births 1989-1994
Folic acid and congenital anomalies • Evidence that 50-75% of spina bifida, can be prevented with supplemental vitamins containing folic acid. (Wald, 1991/ Czeizal,1992, ) • Estimated that 20% of all birth defects, in addition to SB, could also be prevented with the use of vitamin supplements (Botto et al AJMG, 2004) • Evidence that Folic acid supplementation specifically reduces heart defects-(Czeizel 1998, 2004; Shaw et al 1995, Botto et al 2000, Godwin et al 2008) • Public health efforts to encourage all women of childbearing years to take a multivite containing 400µg of folic acid • But variable willingness to adopt the daily use, aboriginal populations often more hesitant to adopt use • Mandatory fortification of flour commenced in Canada, US in 1998 equivalent amounts projected to increase daily intake by 100µg
Folate is considered a ‘nutrient of concern’in the Canadian North • Pre fortification: 219 Cree women in the James Bay region, the average intake of folate was less than 98-128 μg/day. Arbour,Delormier T, IJCH 2002; 61:341-351 • Post-fortification: Dietary Folate/Folic acid (DFE) intake after fortification of women of CB years on Baffin • 2 seasons 24 hour recalls, • FFQ, and 7 day food record 15-18 years 209 µg/day 20-40, with 263 µg/day Folate is obtained largely with fortified foods” Kuhnlein HV; Egeland G; J. Nutrition 2004;134:1447-1453
Then and Now: Has folic acid fortification reduced the rate of congenital anomalies in Nunavut (2000-2006)? • Identical to the first review of 1989-1994 • 2018 perinatal and pediatric charts of children residing on Baffin Island 2000-2006 were reviewed • As per international standards, congenital anomalies collected until 1 year, exclusions for specific birth defects associated with prematurity • Only confirmed CA recorded (echocardiogram confirmed) • Compared to previous review and ACASS and OR with 95% CI
25% of births to mothers under 20 years. Preterm births 12%, Vs 8% nationally Alcohol use 13% Any substance (alcohol, marijuana, cocaine) 16% >80% were smoking at first prenatal appointment Vs 12% nationally 20% were smoking >10 cigarettes/day Demographics and risk factors n=2018
2000-2006 Chart review-all BD (excluding chromosome abnormalities, genetic syndromes and birth defects associated with prematurity) Candace Sy MD UBC
2000-2006 chart review -cardiac defects (excluding chromosome abnormalities, genetic syndromes and birth defects associated with prematurity) Candace Sy MD UBC
Are there genetic, nutrient, other factors influencing the rate of heart defects?
Genetic/Nutrient determinants of heart defects: Methods • Inuit children with heart defects confirmed with echocardiography (85% VSD/ASD) and their mothers were invited to participate in a case-control study (recruited through cardiology clinic and home communities) • Nutrient intake, pregnancy exposures, RBC folate, serum cobalamin, homocysteine, and six functional polymorphisms for genes important in folate metabolism and uptake (MTHFR A222V, E429A, MTRR I22M, RFC-1 H27R, BHMT R239Q, MTHFD1 R653Q). • Controls were mothers (ages 18-45) of Inuit children without heart defects, invited from the same community, reducing the risk of population stratification. • HWE was evaluated for each polymorphism in the controls, and odds ratios with confidence intervals were calculated for both cases and their mothers using the controls as referent.
8 Communities Cases=61 Mothers of cases=60 Mothers of controls=58 Participants
Results • No mothers of cases or controls were taking vitamins peri-conceptionally • No mothers of cases or controls were taking vitamins at the time of the study • Most took some vitamins during pregnancy • There was no difference in pregnancies exposed to alcohol (~25%) in cases or controls • There was no difference in pregnancies exposed to cigarette smoking during pregnancy (~80%)
Results p=0.96 p=0.94 P=0.36 953 Vs 957 nmol/L p=.94
In summary • The causes of heart defects and other birth defects in Nunavut are likely multifactorial: including genetic predisposition, maternal exposures, diet and other complex factors that also predispose to prematurity. • Folate fortification alone is not likely to be a panacea. But is the amount of fortification sufficient for this Northern population?
3rd International Polar Year Inuit Health Survey (2007-2008) Dr. Grace Egeland Steering Committees From the Inuvialuit Settlement Region, Nunatsiavut Region, and Nunavut guided the research Funded by Canadian Federal Program for IPY, ArcticNet, Indian and Northern Affairs Canada and Health Canada
The Inuit Health SurveyFolate levels in women of childbearing years • RBC folate measured in women of childbearing years (18-40) • Survey: • 24 hour dietary recall • Education, level of food security (food insecure, moderate insecurity, secure), number of cigarettes smoked, number of years smoking • Total participants 249 (77% were from Nunavut) • Average age: 29. 1 (± 6) years • 83.2% current smokers • 6% taking vitamins Kait Duncan
. Comparison of compiled red cell folate mean from all three sites, and site-specific means, to national red cell folate mean for women of childbearing age. Results • Average RBC folate (without vitamin users) =922.9nmol/L • Total population=935.7 nmol/L • All regions lower than Canadian average -1,279.0 50.9 nmol/L (Canadian Health Measures Survey 2007-2009) • But still reach target RBC of about 900 nmol/L to prevent birth defects
Red cell folate from Inuit women of childbearing age Average =935.7 192.0 nmol/L Kait Duncan UBC
Red cell folate values from Inuit women of childbearing age across all three sample sites. (935.7 192.0 nmol/L). Can we identify those who might benefit from supplements? Kait Duncan UBC
Some women may benefit by the use of multivitamins pre-conceptionally and throughout pregnancy • To identify those women for targeted interventional prevention programs will be a challenge
A chart review of those born between January 1st 2003 and January 1st 2006 were utilized (1022 births) since smoking status was recorded at the first prenatal visit on 90% (N=918) of prenatal charts, and of those smoking, 80% of charts also included number of cigarettes smoked per day. Birth weight at term, prematurity, low birth weight, SGA, and substance use was assessed by category for those not smoking (n=175) as recorded on first prenatal visit, smoking 1-4 (n= 215) 5-9 (n=196), >10 (n=181), and smoking but no quantity recorded (n=151). Total smokers n=743 (81%). What about other birth outcomes? Mehaffey et al Rural and Remote Health 10: 1484. 2010: http://www.rrh.org.au
Birth weight of term infants according to smoking categories one way ANOVA, p<0.05
Is there an association with drug other substance use and smoking > 10 cigarettes per day
In summary For Inuit women smoking less than 5 cigarettes per day pregnancy outcomes were consistently better than average outcomes in the rest of Canada! Smoking > 10 cigarettes per day at first pregnancy visit is associated with a significantly increased risk for preterm birth, sGA, and low birth weight The reasons for the increased risk in this group are likely multifactorial, and not due to smoking alone, more information is needed to understand the complex interactions Recognizing and supporting those women who report smoking greater than 10 cigarettes per day at first prenatal visit might improve outcomes
Infant mortality • "The infant mortality rate—the rate at which babies of less than one year of age die—reflects economic and social conditions for the health of mothers and newborns, as well as the effectiveness of health systems," states the OECD Factbook 2010
Infant Mortality in Inuit Inhabited Areas of Canada (1990-2000) • Compared to the rest of Canada, Inuit inhabited areas had higher rates of: • Prematurity ( RR 1.45) • Infant mortality (comparable to 1970’s) • Post-neonatal infant mortality (RR 6.21) • SIDS (RR 7.15) • Infant deaths due to infections (RR 8.3) • Rates still higher when Inuit inhabited areas were compared to rural and Northern Canada Infant mortality rates in Inuit inhabited areas and the rest of Canada (1990-2000) per 1,000 live births Data and graph courtesy of Sacha Senécal, Indian and Northern Affairs Canada and the University of Western Ontario Luo et al CMAJ 182 (3) 235-242
Methods • Research Partner: Nunavut Tunngavik Inc • As part of a study exploring a metabolic cause of infant mortality (CPT1A P479L) all causes of infant mortality cases available were reviewed for the years 1999-2008 • Ethics review UBC and NRI • Data Sources-CMOH office, coroners office (Iqaluit) and vital statistics (Rankin Inlet) Data collected when available • Age at death • Cause of Death • Sex • Gestational Age (wks) • Place of Residence • Sleep Position - found • Sleep Position - placed • Bed-sharing • Smoking present in environment • Alcohol present in environment • Breast feeding • CPT-1 P479L results S. Collins. MSc Candidate UBC
SIDS and SUD in Nunavut2000-2008 • SIDS and SUDI deaths as a proportion of all deaths under 1 year of age in Nunavut (2000-2008; Nunavut Coroner’s Office) and Canada (2000-2005; Statistics Canada) S. Collins MSc candidate
SIDS - causes • When an infant suddenly dies in his/her sleep with no apparent illness or physical harm, it is termed as SIDS • Genetic variants can predispose infants to SIDS (eg. Genetic causes of cardiac arrhythmia, fatty acid abnormalities) • Physiological factors such as anemia, respiratory infection, neuronal (brain cell) immaturity can all be involved • Smoking prenatally increases the risk for SIDS (by altering the brainstem, arousal from sleep, blood vessels of the infants). • The other significant component involved is the physical environment –soft mattress, hyperthermia • Physiological factors (eg. neuronal immaturity) + vulnerable environment (eg. prone sleeping) = may be fatal S. Asuri
Sleep Position • Sleeping on the back is the safest sleep position for infants • SIDS worldwide was decreased by 50-90% by laying infants to sleep on their backs • Sleeping prone– can physically block infant’s airways, alter the arousal responses of infants in response to respiratory stress (sleep deeper) “Not on my tum mum” “Look up to our ancestors” “Back to Sleep” www.nichd.nih.gov/sids/ S. Asuri
But Mothers in Nunavut less likely to adopt supine position (<50%) • 2006 Maternity Experiences Survey • 2006 Aboriginal Children’s Survey
A tri-territorial case cohort study to determine prevalence of the CPT1A variant and whether there is an increased risk for infant mortality-S. Collins • Genotyping prevalence study of all those born in 2006 in Nunavut, NWT and Yukon (Collins et al 2010 Molecular Genetics and Metabolism) • Genotype all unexpected infant deaths from 1999-2008 present: Odds Ratio for Nunavut: 3.86 (95% CI: 1.185-22.3841) Research team: L. Arbour (S. Collins), H. Vallance, C. Greenberg, G. Sinclair
Understanding and preventing infant mortality in Nunavut • Collaborative effort with NTI, Health and Social Services and Arctic Health Research network -Focus groups -Health promotion according to focus group response -Qiturngatta–our children”
The QSS surveillance system has now been initiated from 16 weeks gestation to 5 years of age. • Food security, blood glucose in pregnancy, paternal and maternal occupations, exposures, birth outcomes, newborn screening results, safe sleep practices, well child visits, developmental assessments will be part of a public health maternal child health surveillance system which builds and expands from regional models of perinatal and birth defect surveillance. Samantha Lauson (QSS coordinator, Uvic)
Summary • Most women in Nunavut have positive birth outcomes • But food insecurity, sub-optimal folate levels, high smoking rates, lack of adoption of supine sleep position and genetic factors ….all likely influence birth outcomes. • Priority efforts to further understand and reduce infant mortality are under way. • More information is needed to understand the complex interactions involved in smoking practices that seem to influence rates of prematurity, low birth weight, and possibly birth defects.
This information is just the tip of the iceberg..More is needed to act effectively…but translating the data collection into health improvement will remain the greatest challenge.