Geographic Variation in Maternal Smoking during Pregnancy in the Missouri Adolescent Female Twin Study (MOAFTS).
OBJECTIVE
Despite well-known adverse health effects of maternal smoking during pregnancy (MSP), it is still unclear if MSP varies geographically and if neighborhood socioeconomic deprivation (SED) plays an important role in MSP. This study aims to investigate small-area geographic variation in MSP and examine the association of SED with MSP.


METHODS
The Missouri Adolescent Female Twin Study (MOAFTS) is a cohort study of female like-sex twins born in Missouri to Missouri-resident parents during 1975-1985. Biological mothers completed a baseline interview in 1995-1998 and reported MSP with the twins. Residential address of the mother at birth was geocoded. We developed a census tract-level SED index using a common factor approach based on 21 area-level socioeconomic variables from the 1980 Census data. Multilevel logistic regressions estimated geographic heterogeneity (random effect) in MSP and the odds ratios (ORs, fixed effects) of neighborhood SED associated with MSP.


RESULTS
Of 1658 MOAFTS mothers, 35.2% reported any MSP and 21.9% reported MSP beyond the first trimester. Neighborhood SED was associated with any MSP (the highest vs. the lowest quartile: OR = 1.90, 95% confidence interval [CI] = 1.40-2.57, Ptrend<0.001) and MSP beyond the first trimester (OR = 1.98, 95% CI = 1.38-2.85, Ptrend = 0.002) in unadjusted analyses. After adjusting for individual covariates (demographics, socioeconomic conditions, alcohol use, and parents' cohabitation), neighborhood SED was not associated with MSP, but geographic variation still persisted in MSP (variance = 0.41, P = 0.003) and in MSP beyond the first trimester (variance = 0.82, P<0.001).


CONCLUSIONS
Neighborhood SED was associated with MSP in unadjusted analyses but this association could be explained by individual socioeconomic conditions. Nonetheless, significant geographic variation in MSP persisted and was not accounted for by differences in neighborhood SED. To develop effective interventions to reduce MSP, further studies are necessary to explore underlying reasons for its geographic variation.
Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States of America.|Cancer Prevention and Control Program, Alvin J. Siteman Cancer Center, Barnes-Jewish Hospital, and Washington University School of Medicine, St. Louis, MO, United States of America.
Min
M
Lian
Cancer Prevention and Control Program, Alvin J. Siteman Cancer Center, Barnes-Jewish Hospital, and Washington University School of Medicine, St. Louis, MO, United States of America.|Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States of America.
Pamela A
PA
Madden
Addictions Department, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom.
Michael T
MT
Lynskey
Cancer Prevention and Control Program, Alvin J. Siteman Cancer Center, Barnes-Jewish Hospital, and Washington University School of Medicine, St. Louis, MO, United States of America.|Department of Surgery, Washington University School of Medicine, St. Louis, MO, United States of America.
Graham A
GA
Colditz
Cancer Prevention and Control Program, Alvin J. Siteman Cancer Center, Barnes-Jewish Hospital, and Washington University School of Medicine, St. Louis, MO, United States of America.|Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States of America.
Christina N
CN
Lessov-Schlaggar
Cancer Prevention and Control Program, Alvin J. Siteman Cancer Center, Barnes-Jewish Hospital, and Washington University School of Medicine, St. Louis, MO, United States of America.|Department of Epidemiology, College for Public Health and Social Justice, St. Louis University, St. Louis, MO, United States of America.
Mario
M
Schootman
Cancer Prevention and Control Program, Alvin J. Siteman Cancer Center, Barnes-Jewish Hospital, and Washington University School of Medicine, St. Louis, MO, United States of America.|Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States of America.|Midwest Alcoholism Research Center, Washington University School of Medicine, St. Louis, MO, United States of America.
Andrew C
AC
Heath
D000293:Adolescent; D000328:Adult; D005191:Family Characteristics; D005260:Female; D005843:Geography; D006801:Humans; D008923:Missouri / Q000453:epidemiology; D009035:Mothers / Q000523:psychology*; D016017:Odds Ratio; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology / Q000209:etiology*; D011446:Prospective Studies; D012111:Residence Characteristics; D012907:Smoking / Q000009:adverse effects*; D012959:Socioeconomic Factors; D055815:Young Adult