1. NCRM is funded by the Economic and Social Research Council Fertility histories and later life health Emily Grundy and Sanna Read Website http://pathways.lshtm.ac.uk Emailpathways@lshtm.ac.uk Twitter@pathwaysNCRM

2. NCRM is funded by the Economic and Social Research Council Determinants of health in mid and later life Life course influences are recognized to be important, but most attention paid to socio-economic (and early life) factors Largely separate literature has shown differences by marital and household status and social support, more recent attention to partnership and parenting histories This literature has examined associations between the fertility histories of women (and less usually men) and mortality or health measured at one point in time Several, but not all, studies show worse health/higher mortality for nulliparous and high parity women (and men). Early parenthood is associated with poorer later health/mortality (women) and poorer later mental health (women and men) Late fertility associated better health/lower mortality in both women and men (but some studies the reverse)

3. NCRM is funded by the Economic and Social Research Council Childrearing and health: Health promoting : Incentives towards healthy behaviours and risk avoidance More social participation and activity Role enhancement Social support - in childrearing phases and in later life Health challenging: Physiological demands of pregnancy, childbirth and lactation (although reduced risk breast & some other hormonally related cancers) Potential role conflict/role overload Stress (and depression) Economic strain Increased exposure infections Disruption of careers/education – especially for young parents

4. NCRM is funded by the Economic and Social Research Council Associations between fertility histories and mortality in later life –Selection and reverse causation –Direct effects e.g. physiological consequences of pregnancy and childbirth. –Indirect effects e.g. costs/benefits of child rearing mediated by factors such as social support and health related behaviours.

5. NCRM is funded by the Economic and Social Research Council Possible selection effects Poor health/health behaviours may restrict opportunities for marriage and reduce fertility (obesity, excessive alcohol and smoking all associated with fecundity of both women and men). Antecedent disadvantage associated both with early parenthood and with later poorer health Late fecundity and fertility may be marker of slower ageing/better health

6. NCRM is funded by the Economic and Social Research Council Gender, age and SES variations/interactions Physiological effects of pregnancy/childbirth: mainly applicable women but some evidence of hormonal changes in new fathers Early childbearing may disrupt attainment adult career/educational roles Late childbearing may be stressful if perceived as ‘off time Ages at which mortality/morbidity observed may be important because of associations between cause and age of death Stress: negative effects likely to be greater for lone parents, those on low incomes and those with more stressful parenting histories (many children, children early in life). Social support: Women have closer links adult children, but some evidence that social support from children more important for health of older men – especially poorly educated Upward transfers greater to lower SES parents: support of children therefore potentially more important Life style/behavioural: effects noted for women and men – modified by residence with children.

7. NCRM is funded by the Economic and Social Research Council Fertility history and later life health: previous research : Data sources and outcomes investigated: All cause mortality: Norwegian population registers; ONS Longitudinal Study (E&W): USA Health and Retirement Survey linked to mortality Cause specific mortality: Norwegian population registers Health, health trajectories, mental health: USA HRS; UK British Household Panel Study; English Longitudinal Study of Ageing, 1946 birth cohort (NSHD). Quality of life, loneliness, social contacts, receipt of help from children: ELSA

8. NCRM is funded by the Economic and Social Research Council Fertility history and mortality ages ~45-69 comparing England & Wales, Norway & USA (controlling for age, marital & socio-economic status &, in USA, race/ethnicity). E&W deaths 1980 2000 at ages 50-69 Norway deaths 1980 2003 at ages 45-68 USA deaths 1994 2000 at ages 53-69 ALL Women/Men:OR 01.281.501.47 11.101.311.34 2 (ref)1.00 31.010.951.21 41.110.951.41 5+1.250.941.66 PAROUS Birth before 20 (F)/23 (M)1.301.211.55 Birth after 390.940.860.74 Number of deaths2,21223,241329 Analysis of ONS LS data ; Norwegian register data & US HRS, Grundy 2009. P<0.05; P<0.10

9. NCRM is funded by the Economic and Social Research Council Associations between parity and mortality by cause group, Norwegian women aged 45-68 Controlling for age, year, education, marital status, region, log population size of municipality, Grundy & Kravdal 2010.

10. NCRM is funded by the Economic and Social Research Council BHPS analysis: Measures Fertility history: Number of natural children (0, 1, 2, 3, 4+); for parous: young age at first birth ( 35/39; for parents with 2+ births: any birth interval < 18 months. Co-variates: Education; marital status; housing tenure; smoking; emotional support; co-residence with children (parents only)- all time varying except emotional support. Variables hypothesised to be associated with sample retention- interviewers’ reports of problems with interview; recent mover; foreign born. Outcomes: Self rated health: Excellent, Good, Fair, Poor, Very poor. Ordinal variable, higher=worse. Health limitation: “Does your health in any way limit your activities compared to most people of your age?”

11. NCRM is funded by the Economic and Social Research Council BHPS analysis: Results for a) parous men & women and b) parous with 2+ children Health limitationsSelf-rated health MenWomenMenWomen a) Parous respondents: Number of children: 1 + 3 4+ +++ Birth before 23/20 +++ ++ Birth after 39/35 b) Parity 2+; spacing effects Number of children: 3 + 4+ +++ Birth before 23/20 +++++ Birth after 39/35 Birth interval < 18 months +++++

12. NCRM is funded by the Economic and Social Research Council Rate-of-change in health over 11 years: Predicted probability of health limitation by fertility history characteristics, British women born 1923-49 (reference group = women with 2 children born when mother 20-34) Source: Analysis of BHPS data in Read, Grundy & Wolf, Population Studies 2011

13. NCRM is funded by the Economic and Social Research Council BHPS analysis: key findings High parity (4+ children) associated with health limitation and worse self-rated health among women and men Also a slightly higher risk of health limitation for childless women Early parenthood for parous) and short birth intervals (among those with 2+ children) associated with higher risk of health limitation, worse self rated health and faster accumulation of health limitation

14. NCRM is funded by the Economic and Social Research Council Are children the key to a health and happy old age? Yes More children increases chance of social contacts ; for parents especially having a daughter More children associated with more help from children Parents (of smallish families) seem to have lower mortality and better health than the childless No High parity associated higher mortality and worse health ‘Intensive’ family formation patterns – early parenthood and short birth intervals- associated with worse health and faster decline in health BUT the context is very important – known variations and interactions by Gender, country, education etc AND we need to consider selection.

15. NCRM is funded by the Economic and Social Research Council Limitations of previous work Outcome measures – mortality and ADL limitation- may be too far ‘upstream’ – need indicators of sub clinical morbidity observable earlier in life course Failure to identify PATHWAYs through which fertility histories influence later life health Limited consideration of early life influences on both fertility histories and later health Addressing these limitations Measures of allostatic load in mid and later life SEM and path analysis to identify pathways Modelling including early life indicators 15

16. NCRM is funded by the Economic and Social Research Council Progress to date: Identifying earlier health outcomes: derivation of a measure of allostatic load using data from the English Longitudinal Study of Ageing (ELSA) Identifying pathways from fertility histories to later life health (via allostatic load). In progress; taking account of early life influences 16

17. Allostatic load a multisystem dysregulation state resulting from accumulated physiological ‘wear and tear’ Allostasis = a process whereby organism maintains physiological stability by adapting itself to environmental demands - > health is a state of responsiveness and optimal predictive fluctuation to adapt to the demands of the environment -> dynamic biological process interacting with context

18. Factors associated with allostatic load in previous studies Socioeconomics: education, income, occupational status, downward mobility, homelessness Family: attachment, violence, single parent, separation, care-giving, demands/criticism, spouse Individual: type A/hostility, locus of control, a polymorphism of ACE gene Neigbourhoods: crowding, noise, lack of housing, rural/urban Allostatic load Ethnicity: Non- whites (U.S.) Spirituality: religious attendance, sense of meaning/purpose Social networks: emotional support, social position Work: control, demands, decisions, career instability, effort- reward imbalance

19. Sample English Longitudinal Study of Ageing (ELSA) waves 1 - 4 (2002-2008) men and women (n = 5279) aged 50+ in 2002 Measures: – Biomarkers available in waves 2 and 4 – Health: self reported health, limitation in health, ADL and IADL limitation – Fertility history: number of children, birth before age 20 (women) or age 23 (men), birth after age 34 (women) and 39 (men), coresidence with child – Background factors: age, marital status, qualification, tenure status, net wealth quintile (non-pension wealth indicating financial, physical and housing wealth net of debts)

20. Selected biomarkers to measure allostatic load in ELSA Neuro- endocrine ImmuneCardiovascularRespiratoryMetabolicBody fat DHEAS* (dehydroepia ndrostorone sulphate) C-reactive protein Systolic blood pressure Peak expiratory flow Total blood cholesterol/ HDL cholesterol ratio Waist-hip ratio FibrinogenDiastolic blood pressure Triglycerides IGF-1* (insulin-like growth hormone) Glycated HgB * only in wave 4

21. Allostatic load scores in ELSA Group allostatic load index: number of biomakers indicating high risk (25th percentile) calculated separately for men and women, range 0 - 9 Upper 25 th percentileLower 25 th percentile Systolic blood pressureDiastolic blood pressure FibrinogenPeak expiratory flow Triglycerides C-reactive protein Glycated HgB Waist-hip ratio Total/HDL cholesterol ratio

22. Allostatic load change in ELSA Is change associated with any of the following factors? Age Qualification, tenure status, net wealth quintile Being married Perceived support and critique received from family and friends Number of children Coresidence with child, early child birth, late child birth (among parents only)

23. Allostatic load change in ELSA Comparison between wave 2 (2004) and wave 4 (2008): Low allostatic score (score 0-1) and high allostatic score (2+) High Low 20042008

24. Does allostatic load predict later disability?:Allostatic load measures in 2004 and ADL limitations in 2006 in men in ELSA ADL problem % Lowest 25% Highest 25%

25. Allostatic load change in ELSA

26. Allostatic load change between 2004 and 2008 in ELSA

27. Allostatic load change in ELSA

29. Results from fully adjusted model

30. Allostatic load change in ELSA Results from full adjusted model

31. Allostatic load change in ELSA Is change associated with any of the following factors? Age -> Yes Qualification, tenure status, net wealth quintile -> Yes Being married -> No Perceived support and critique received from family and friends -> Yes n of children -> Yes coresidence with child, early child birth, late child birth (among parents only) -> No

32. Fertility history Allostatic load Health Education Is the association between fertility history and health mediated by allostatic load? Does SEP influence this association? The model to be tested Wealth

33. 4+ children vs. 2 children Allostatic load Health Education All men Wealth Model adjusted for age. Unstandardized estimate and standard error shown. -0.282 (0.070) 0.897 (0.070) -0.499 (0.088) -0.186 (0.023) 0.144 (0.015) -0.097 (0.022)

34. Early birth Allostatic load Health Education Parous men Wealth Late birth Model adjusted for age, n of children and coresidence with child. Unstandardized estimate and standard error shown. 1.238 (0.400) -0.555 (0.130) -0.239 (0.087) -2.884 (0.765) -0.209 (0.032) 0.238 (0.400) -0.157 (0.016) 0.136 (0.022) 7.691 (2.310)

35. 0 children vs. 2 children Allostatic load Health Education All women Wealth 4+ children vs. 2 children Model adjusted for age. Unstandardized estimate and standard error shown. 0.779 (0.254) 1 child vs. 2 children -3.637 (0.995) -0.124 (0.060) 0.136 (0.026) 0.784 (0.253) 0.290 (0.079) -0.461 (0.075) -0.239 (0.087) -0.095 (0.034)

36. Early birth Allostatic load Health Education Parous women Wealth Model adjusted for age, n of children, late birth and coresidence with child. Unstandardized estimate and standard error shown. 0.631 (0.060) 0.103 (0.015) -0.168 (0.023) 0.174 (0.046) -0.225 (0.063) -0.248 (0.079) -0.064 (0.012) -0.735 (0.112)

37. Is the association between fertility history and health mediated by allostatic load? - Yes, it is in men and to some extent also in women. In women there are also direct paths to health suggesting that there are other potential mediators. Does SEP influence this association? - In men, and to some extent in women, SEP mediates the association between fertility history and later allostatic load and health. Fertility history, allostatic load and health in ELSA

38. Work in progress Refinement of measures of allostatic load including medication use Further modelling of Pathways including life style variables Investigation of Pathways including early life influences Analyses taking account of missing data

39. NCRM is funded by the Economic and Social Research Council - Several time-ordered exposures  intermediate outcomes Early adulthood SEP Health in late adulthood fertility Childhood SEP Stress/ support Smoking, Diet/BMI Smoking Diet/BMI