A Framework for Social and Cultural Determinants of Prematurity

1
A Framework for Social and Cultural Determinants
of Prematurity

• The Role of Environmental Toxicants in Premature
  Delivery
• Session II Environmental Causes of Prematurity
• Carol J. Rowland Hogue

2
Goals of This Presentation

• Briefly review studies of stress and preterm
  delivery
• Present a conceptual framework for understanding
  how stress enters the body
• Explore some of the implications for future
  research of this conceptual model

3
Previous Research on Stress Prematurity

• Stress, in absence of social supports, poor
  pregnancy outcomes
• Randomized trials of stress reduction have
  occasionally been successful

• But effect is generally small, and it is not
  consistently found in various studies
• But most RCTs have not had success
• Included women not in need of support?
• Provided inadequate intimate support?

4
Why is the Stress Effect Weak and Support
Ineffective? Alternative Hypotheses

• Stress does not cause prematurityhowever
  biological plausibility of stress/prematurity
  hypothesis argues against this
• Stress does cause prematuritybut it has been
  inadequately characterized in observational
  studies (and inadequately intervened on in RCTs)

5
The Epidemiologic Triangle
Host
Agent
Environment
6
Host Susceptibility

• Experimental stress that elevated blood pressure
  in some women associated with BW
  gestation.
• Experiments with stress BP suggest that African
  Americans early life experiences may increase BP
  reactivity
• Critical points in early development create
  reduced neuron plasticity
• Early continual stressors may cause learned
  physiological responses

7
Host Susceptibility

• Personality traits
• Coping style
• Anger, anxiety traits
• Buffering coping resources
• High self-esteem
• Sense of personal control or mastery
• Access to financial resources
• Coping strategies
• Problem-focused vs. emotion-focused
• Directly health related (exercise, eating,
  smoking, ETOH, drugs)

8
Environments or Contexts

• Stressful
• Chronic stressors
• Hassles
• Ameliorating
• Intimate social support
• Material support

9
Environments or Contexts

• The negative health impact of environmental
  stressors does not depend on the individuals
  perception of them.
• Therefore, environmental risk assessment must
  include contextual variables.

10
Environments or Contexts

• Institutionalized Racism
• Segregation
• Geronimus weathering hypothesis
• Now affecting Mexican Americans?
• Poverty
• Consistent association with preterm delivery
• What about poverty is associated?
• Gender
• Chronic household role strain
• Lack of job control in the workplace
• Domestic violence

11
Agents

• Stressful life events
• Acute
• Issues of timing, severity, repetition
• Hard physical labor
• Individual experiences of racial insult

12
The Epidemiologic Triangle
Host
Agent
Environment
13
Implications for Future Research

• Expanding design and analysis of epidemiologic
  studies
• Developing new stress measures
• Selecting theoretical models
• Biopsychosocial
• Adapting sociological theories

14
Implications for Future Research

• Hypothesized mechanisms include
• Stress hormones
• Hypertension
• Reduced immune function/infection

15
Implications for Future Researchexample

• Why do African American women have higher rates
  of vaginal infection-related preterm delivery?
• Hypothesis Independent of exposure to
  infectious agents, African American women have
  increased susceptibility to disease given
  infection because of stress-associated reduced
  immune function.

16
Percent Reporting DiscriminationAfrican
American mothers, Cook County Hospital
Crude OR 1.9 (0.5-6.6) Adjusted OR 3.2
(0.9-11.3)
Collins, Epidemiology 2000