Associations Between Psychosocial Factors and Intrauterine Growth Retardation

1. Associations Between Psychosocial Factors and Intrauterine Growth Retardation Sharon Durousseau MD, MPH California Department of Health Services Maternal Child Health Branch

2. Intrauterine Growth Retardation • Intrauterine growth retardation (IUGR) • Babies born too small for gestational age • Over 10,000 full-term infants with IUGR born in California annually • Increased risk for death and disability • Long-term effects

3. Incidence Rate of IUGR, CA 1992-1999

4. Incidence of IUGR by Race/Ethnicity, CA 1999

5. Psychosocial Factors and IUGR? • Risk factors include • Smoking • Poor nutrition • Prior pregnancy history • Stress and social factors might affect fetal growth

6. Study objectives • Can we identify women at risk by the psychosocial profile? • Can social support programs affect IUGR rates?

7. Maternal Infant Health Assessment • Annual population-based survey • Includes mothers with singleton live births • Surveys maternal behaviors and conditions before, during, and after pregnancy

8. Sampling Design 165,898 All live births in California Feb. to May 1999

9. Sampling Design 165,898 All live births in California Feb. to May 1999 Excluded: -Mothers aged <15 yrs -Infants adopted -Mothers deceased -Incomplete contact information

10. Sampling Design 165,898 All live births in California Feb. to May 1999 Excluded: -Mothers aged <15 yrs -Infants adopted -Mothers deceased -Incomplete contact information 156,514 Eligible Population

11. Sampling Design 165,898 All live births in California Feb. to May 1999 Excluded: -Mothers aged <15 yrs -Infants adopted -Mothers deceased -Incomplete contact information 156,514 Eligible Population Stratified by race/ethnicity, region and education 4,967 Random sample strata

12. Sampling Design 165,898 All live births in California Feb. to May 1999 Excluded: -Mothers aged <15 yrs -Infants adopted -Mothers deceased -Incomplete contact information 156,514 Eligible Population Stratified by race/ethnicity, region and education 4,967 Random sample strata 70.1% response 3,483

13. IUGR Case Definition • A case defined as a mother of a term infant ( >37 weeks gestational age) weighing < 2500 grams at birth • All other term infants were non-cases

14. Cases and Non-cases 3,483 3,127 mothers of term infants

15. Cases and Non-cases 716 preterm excluded 3,483 3,127 mothers of term infants

16. Cases and Non-cases 716 preterm excluded 3,483 3,127 mothers of term infants 3,054 non-cases 73 cases

17. Psychosocial Factors • Wanting to become pregnant • Initial happiness about becoming pregnant • Maternal sense of control score

18. Statistical Methods • Univariate Analysis with SPSS/SUDAAN • Logistic regression controlling for Race/ethnicity Maternal age Prior low birthweight Smoking status Education Marital status Poverty • Data weighted to reflect state population • Tested for interaction

19. IUGR Risk Factors Crude OR 95% CI < 19 years old 2.4 (1.3, 4.5)> 19 years (ref) African-American 3.1 (1.6 , 6.2) Native American 3.7 (0.5, 29.2) Asian/Pacific Islander 2.9 (1.3, 6.3)Hispanic 1.4 (0.7, 2.6) White/Other (ref)

20. IUGR Risk Factors Crude OR 95% CI < 12 Years education 1.7 (1.01, 2.9) Unmarried 1.7 (1.05, 2.9) Medicaid 1.8 (1.04, 2.9) Income < federal poverty level 2.4 (1.4, 4.1)

21. IUGR Risk Factors Crude OR 95% CI Prior Low Birth Weight Infant 12.7 (5.6,28.8) Underweight prior to pregnancy 2.4 (1.3, 4.2) Smoked during pregnancy 1.7 (0.9, 3.3) Alcohol use during pregnancy 0.8 (0.4, 1.6) No first trimester Prenatal Care 0.9 (0.4, 1.9)

22. Univariate Analysis: Wanting to Become Pregnant

23. Univariate Analysis: Happiness About Becoming Pregnant

24. Univariate Analysis: Maternal Sense of Control Scores

25. Multivariate Analysis OR 95% CI Did not want/Unsure 2.2 (0.8, 6.7) Very unhappy 1.5 (0.2, 9.5) Low control score 1.3 (0.2, 9.2)

26. Strengths and Weaknesses • Strengths • Population based sample • Diverse population • Weaknesses • Retrospective, possible recall bias • Limited detail • Possible low power

27. Conclusions • Psychosocial factors associated with IUGR include • Not wanting/being unsure about becoming pregnant • Being unhappy about becoming pregnant • After adjusting for other variables, these factors are not statistically significant.

28. Implications • Assessing maternal feelings toward pregnancy not sufficient to identify women at risk for having infant with IUGR • Consider other risk factors • More focused or prospective study might be needed to explore relationship further

29. Acknowledgements • Gilberto Chavez • Don Taylor • Kristen Marchi • Paula Braveman • Rhonda Sarnoff • Andrea Winquist

30. Pregnancy Wantedness • “ Thinking back to just before you got pregnant, how did you feel about getting pregnant? ” • I wanted to get pregnant then. • I wanted to get pregnant later. • I did not want to get pregnant then or in the future. • I wasn’t sure what I wanted.

31. Initial Happiness About Becoming Pregnant • How did you feel when you found out you really were pregnant ? • Very happy • Somewhat happy • Somewhat unhappy • Very unhappy

32. Maternal Sense of Control • Aggregate score from series of seven questions • “ How much do you agree with each of the following statements ? ” • Sample questions: • “ I have little control over the things that happen to me.” • “ What happens to me in the future mostly depends on me.”

33. Power Calculations • Sample sizes needs to detect 50% difference for each variable ( = 0.05 and  = .20) • wantedness 1,088 • happiness 4,702 • control score 7,738 • Power calculation done in EPI 6.0.