The effect of smoking during pregnancy on severity and directionality of externalizing and internalizing symptoms: A genetically informed approach

• Type of Material: Article
• Authors: Mikael O. Ekblad, Turun Yliopistollinen Keskussairaala; Kristine Marceau, College of Health and Human Sciences; Emily Rolan, Michigan State University; Rohan Palmer, Emory University; Alexandre Todorov, Washington University in St. Louis; Andrew C. Heath, Washington University in St. Louis; Valerie S. Knopik, College of Health and Human Sciences
• Language: English
• Date: 2020-11-01
• Publisher: MDPI
• Publication Version: Final Published Version
• Copyright Statement: © 2020 by the authors.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.3390/ijerph17217921
• Title of Journal or Parent Work: International Journal of Environmental Research and Public Health
• Volume: 17
• Issue: 21
• Start Page: 1
• End Page: 14
• Grant/Funding Information: This research was funded by the Foundation for Pediatric Research (Finland, to M.O.E.), the Orion Research Foundation sr (to M.O.E.), the Emil Aaltonen Foundation (to M.O.E.), the Paulo Foundation (to M.O.E.), the Maud Kuistila Memorial Foundation (to M.O.E.), and the Turku University Hospital Research Foundation (to M.O.E.), and the National Institute of Health; Grant numbers: DA023134 (V.S.K.), DA17671 (V.S.K.), AA07728 (A.C.H.), AA09022 (A.C.H.), AA11998 (A.C.H.), HD049024 (A.C.H.), AA017688 (A.C.H.), AA021492 (A.C.H.), R01DA04272 (R.H.C.P.), K01DA039288 (K.M.).
• Keywords: Pregnancy; Siblings; tobacco; sibling comparison; Behavioral Symptoms; Prenatal Exposure Delayed Effects; Female; health consequences; Antisocial Personality Disorder; Missouri; prenatal exposure; Child; Humans; Smoking; Adolescent; Male; genetically-informed designs
• Research Categories: Health Sciences, Human Development; Health Sciences, Obstetrics and Gynecology; Health Sciences, Public Health

Abstract

The objective was to examine the association between maternal smoking during pregnancy (SDP) and (I) severity and (II) directionality of externalizing and internalizing symptoms in a sample of sibling pairs while rigorously controlling for familial confounds. The Missouri Mothers and Their Children Study is a family study (N = 173 families) with sibling pairs (aged 7 to 16 years) who are discordant for exposure to SDP. This sibling comparison study is designed to disentangle the effects of SDP from familial confounds. An SDP severity score was created for each child using a combination of SDP indicators (timing, duration, and amount). Principal component analysis of externalizing and internalizing behavior, assessed with the Child Behavior Checklist and Teacher Report Form, was used to create symptom severity and directionality scores. The variance in severity and directionality scores was primarily a function of differences between siblings (71% and 85%, respectively) rather than differences across families (29% and 15%, respectively). The severity score that combines externalizing and internalizing symptom severity was not associated with SDP. However, a significant within-family effect of SDP on symptom directionality (b = 0.07, p = 0.04) was observed in the sibling comparison model. The positive directionality score indicates that SDP is associated with differentiation of symptoms towards externalizing rather than internalizing symptoms after controlling for familial confounds with a sibling comparison model. This supports a potentially causal relationship between SDP and externalizing behavior.