1. Maternal Substance Use During Pregnancy and Increased Risk of SIDS among African Americans Fern R. Hauck, M.D., M.S. 1,2 Mark E. Smolkin, M.S. 2 University of Virginia 1 Department of Family Medicine 2 Department of Public Health Sciences APHA Annual Meeting November 2007, Washington, DC

2. Context  Sudden infant death syndrome (SIDS) is the leading cause of death among infants 1 month – 1 year of age  African American infants are twice as likely to die as White infants  Maternal smoking in pregnancy is a major risk factor for SIDS  Little is known about racial differences in smoking as a risk factor  Little is known about illegal drug use as a risk factor, independent of smoking

3. Objectives To determine: 1. If maternal prenatal smoking is a risk factor for SIDS among African Americans 2.If maternal prenatal drug use contributes to the excess risk of SIDS among African Americans, and 3.If this is independent of smoking.

4. Chicago Infant Mortality Study (CIMS) - Methods 1 : 1 Matched Case-Control Study SIDS Controls Matched on: Race Age Birthweight

5. Case Ascertainment and Eligibility  Cases identified through Cook County Medical Examiner, November 1993 - April 1996  Chicago residents only  Infants under 1 year of age who died with a final diagnosis of SIDS

6. Control Recruitment  Randomly selected from birth certificates, using matching criteria  Invited to participate  Small incentive

7. Data Collection for Cases  Autopsy, death scene investigation, and review of the infant’s medical history to determine cause of death  Follow-up home interview and mailed survey to assess additional environmental and social factors  Medical records of mother (labor and delivery) and newborn

8. Data Collection for Controls  Home interview, mailed survey and review of medical records of mother and infant  IRB approval for study from all participating hospitals

9. Results: Descriptive Characteristics of SIDS Cases and Controls (N = 260 pairs) Demographic Characteristics Cases (%) Controls (%) Birth weight < 1,500 g 4 1 1,500 - 2,499 g 24 26 2,500+ g 72 73 Race African American 75 75 Hispanic 13 13 White, non-Hispanic 12 12 Gender Male 57 51 Female 43 49

10. Demographic Cases Controls P-values Characteristics Infant’s age in days (S.D.) 89 (57) 86 (57)NS (at death/interview) Mother’s age in years (S.D.) 23.2 (5.4) 24.8 (6.5)0.001 (this birth) Descriptive Characteristics of SIDS Cases and Controls (Continued)

11. Maternal Prenatal Smoking by Race Smoking Rates CasesControlsP-value Total126 (49%)49 (19%)<0.001 Blacks105 (54%)43 (22%)<0.001 Whites 21 (32%) 6 (9%) 0.001 Difference between Black and White SIDS cases: P = 0.003

12. Maternal Prenatal Drug Use by Race Drug UseCasesControlsP-value Total80 (31%)22 (9%)<0.001 Blacks78 (40%)21 (11%)<0.001 Whites2 (3%) 1 (2%)0.56 Difference between Black and White SIDS cases: P < 0.001

13. Drugs Used by Mothers Drug UseCasesControls Total Cocaine Marijuana Heroin 64 (25%) 37 (14%) 23 (9%) 16 (6%) 11 (4%) 4 (2%) Black mothers Cocaine Marijuana Heroin 62 (32%) 36 (19%) 23 (12%) 15 (8%) 11 (6%) 4 (2%) White mothers Cocaine Marijuana Heroin 2 (3%) 1 (2%) 0 (0%) 1 (2%) 0 (0%)

14. Maternal Prenatal Smoking and SIDS Risk among African American Infants PrenatalUnadjusted Adjusted OR** Characteristics OR (95% CI*) OR (95% CI*) Any smoking4.4 (2.7-7.4)4.2 (2.2-8.1) Amount: < ½ ppd3.8 (2.0-7.1)3.2 (1.5-6.7) ½-<1 ppd4.3 (2.1-9.0)5.5 (2.1-14.3) >1 ppd6.4 (2.0-20.4)8.7 (1.8-42.8) * 95% confidence interval, based on Wald estimates ** Adjusted for maternal age, marital status, prenatal care Kessner Index, education, sleep position, bed sharing

15. Maternal Drug Use and SIDS Risk among African American Infants PrenatalUnadjusted Adjusted OR** Characteristics OR (95% CI*) OR (95% CI*) Any drug use6.2 (3.3-11.7)5.7 (2.6-12.8) Kind of drug: Cocaine6.9 (3.3-14.4)6.5 (2.6-16.2) Marijuana3.5 (1.7-7.1)3.2 (1.3-7.7) Heroin5.8 (2.0-16.6)4.7 (1.2-17.7) * 95% confidence interval, based on Wald estimates ** Adjusted for maternal age, marital status, prenatal care Kessner Index, education, sleep position, bed sharing

16. Maternal Drug Use and SIDS Risk among African American Infants Adjusted for Smoking and Alcohol Use in Pregnancy PrenatalAdjusted OR*Adjusted OR** Characteristics OR (95% CI) OR (95% CI) Any drug use3.3 (1.7-8.2)4.0 (1.6-10.0) Kind of drug: Cocaine3.5 (1.3-9.3)4.5 (1.6-12.8) Marijuana2.2 (0.9-5.7)2.2 (0.8-6.2) Heroin2.6 (0.5-12.2)3.7 (0.8-17.1) * Adjusted for maternal age, marital status, prenatal care Kessner Index, education, sleep position, bed sharing, and prenatal smoking ** Adjusted for maternal age, marital status, prenatal care Kessner Index, education, sleep position, bed sharing, and prenatal alcohol use

17. Conclusions  Maternal cigarette and drug use during pregnancy are strongly associated with SIDS risk among African Americans.  There is a dose response associated with smoking and SIDS risk.  Cocaine use is associated with SIDS risk independent of smoking.

18. Conclusions (Continued)  Higher prevalence of these behaviors among mothers of African-American infants who died from SIDS may account in part for the racial disparity in SIDS rates.  Clinicians and clinics caring for pregnant women should routinely ask about smoking and drug use among their patients.  The health care providers need to offer interventions that will benefit the patients’ own health and reduce the risk of SIDS among their infants.

19. Chicago Infant Mortality Study In Collaboration With: Chicago Department of Public Health Cook County Office of the Medical Examiner Participating Hospitals: Children’s MemorialRush-Presbyterian-St. Luke’s Cook CountyUniversity of Chicago Michael ReeseUniversity of Illinois at Chicago Funding: Centers for Disease Control and Prevention National Institutes of Health (NICHD, NIDCD)

20. CIMS Study Team Principal Investigator: Fern R. Hauck, MD, MS Research Study Coordinator: Cathryn Merrick Moore Programmer/Analysts: Stanislaw Herman, Ph.D., J. Mark Donovan, Ph.D., Mark Smolkin, M.S., Mir Siadaty, M.D., M.S. Family Interviewers: Rashaun Calhoun, Larry Nichols Scene Investigators: Revell Whitney, Carlos Latimer, Caprice Ogletree Laboratory Technicians: Naomi Arenson, Yvette Albright Research Assistant/Volunteer: Mishawn Purnell Administrative Assistants: Teresa Herres, Barbara Manning, Catherine Nealon, Kathleen Regalado (deceased)