Number of children

1. Number of children impairs cognitive function in humans (β = -0.023, p < 0.05).

   “This association remained significant even after adjusting for covariates in groups with three (β = -0.023, p < 0.05) and four or more children (β = -0.043, p < 0.001).”

   Humansthree children

   Associations between the Number of Children, Depressive Symptoms, and Cognition in Middle-Aged and Older Adults: Evidence from the China Health and Retirement Longitudinal Study

   Healthcare (Basel, Switzerland)·Sep 26, 2024

2. Number of children improves cognitive function in humans (β 0.29, 95% CI 0.13–0.45).

   “men with any number of children and women with 5+ children had higher cognitive function compared to those without children (β[95% CI]: Men: 1-2: 0.29[0.13 – 0.45]”

   Humansmalesn = 5,059

   Number of children and mid- to later-life cognitive function and cognitive impairment in rural South Africa: Evidence from “Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa” (HAALSI)

   medRxiv·Sep 26, 2023Preprint

3. Number of children impairs cognitive function in humans (β = -0.547, 95% CI: -0.677, -0.416).

   “The cognitive function score decreased significantly with increasing numbers of children [β = -0.547, 95 % confidence interval (CI): -0.677, -0.416].”

   Humansfemalesn = 4,803

   Number of children and cognitive function among Chinese menopausal women: The mediating role of depressive symptoms and social participation

   Journal of affective disorders·Aug 15, 2023

1. Number of children has no effect on longevity in humans.

   “for those with fewer than five children, their longevity was not associated with having more children.”

   Humansparents in Chinafewer than five children

   Number of children, Parental Longevity and Health in later life

   Research Square·Jun 16, 2022Preprint

1. Number of children decreases rural-urban health inequality in humans.

   “the degree of health inequality between urban and rural elderly decreases with the increase of the number of children.”

   Humansn = 9,745

   Children and Rural-Urban Inequality of Health Among Elderly in China: "Convergence Phenomenon" of the Number of Children and "Action Mechanism" of the Quality of Children

   Research Square·Feb 23, 2022Preprint

1. Number of children is associated with cognitive function in humans (β = -0.462, p < 0.001).

   “In the unadjusted model, having three or more children was associated with a significant decline in cognitive functioning (β = -0.462, p < 0.001) compared to those with no children.”

   Humansunadjusted model

   Number of Children and Cognitive Aging in Older Americans: The Role of Socioeconomic Status and Gender Differences

   GSA 2025 abstract·Dec 31, 2025

2. Number of children is associated with cognitive function in humans (episodic memory: B = -.17, p < .001; mental status: B = -.25, p < .001).

   “Parents with multiple children had poorer baseline cognitive functions (episodic memory: B = -.17, p < .001; mental status: B = -.25, p < .001)”

   Humans7 yearsn = 6,723

   Only child or multiple children? The number of children and cognition in older Chinese parents

   Australasian journal on ageing·Mar 1, 2025

1. Number of children raises the risk of depressive symptoms in humans (all p < 0.01).

   “Conversely, the positive association between the number of children and depression also persisted after adjusting for covariates, although it weakened as the number of children increased (all p < 0.01).”

   Humans

   Associations between the Number of Children, Depressive Symptoms, and Cognition in Middle-Aged and Older Adults: Evidence from the China Health and Retirement Longitudinal Study

   Healthcare (Basel, Switzerland)·Sep 26, 2024

More on Depressive symptoms

1. Number of children raises the risk of heart disease and stroke in humans (OR = 2.12 [95% CI: 1.51 to 2.98]).

   “Women with seven or more children had the highest OR for the association between the number of children and incident HDS (OR = 2.12 [95% CI: 1.51 to 2.98])”

   Humansseven or more children vs 1-2 childrenfemalesn = 23,995

   Association between number of children and incident heart disease and stroke in parents - results from the Survey of Health, Ageing and Retirement in Europe (SHARE)

   BMC public health·Nov 24, 2023

More on Heart disease and stroke

1. Number of children lowers the risk of cognitive impairment in humans (PR 0.48, 95% CI 0.31–0.75).

   “for men and women, groups with any number of children showed a lower prevalence of cognitive impairment than the group with 0 children (PR[95% CI] Men: 1-2: 0.48[0.31 – 0.75]”

   Humansmalesn = 5,059

   Number of children and mid- to later-life cognitive function and cognitive impairment in rural South Africa: Evidence from “Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa” (HAALSI)

   medRxiv·Sep 26, 2023Preprint

More on Cognitive impairment

1. Number of children is associated with frailty in humans (r: 0.435, P = 0.001).

   “A weak, positive correlation was found between the total number of children and FI in female participants (r: 0.435; P = 0.001; P< 0.01)”

   Humansfemalesn = 98

   Relationship of the Number of Children and Child Sex with Frailty among Older Turkish Parents

   Research Square·Mar 23, 2023Preprint

1. Number of children is associated with vigorous physical activity for at least 30 minutes daily in humans (AOR 3.169; p = .002).

   “older adults who had above 5 children were 3 times (AOR = 3.169; p = .002) more likely to participate in VPA”

   Humanscommunity-dwelling older adults in Accra, Ghanamore than 5 children versus no childrenn = 686

   Associations between vigorous physical activity, social ties, social support, and self-reported health among older adults in Accra, Ghana

   PLOS global public health·Feb 13, 2023

1. Number of children is associated with mortality in humans.

   “having five or more children significantly increased the risk of death for both rural male older adults and urban older adults”

   Humansrural male older adults and urban older adults in Chinafive or more childrenmale in rural participants; unspecified in urban participantss

   Number of children, Parental Longevity and Health in later life

   Research Square·Jun 16, 2022Preprint