Sex-Specific Alterations of White Matter Developmental Trajectories in Infants With Prenatal Exposure to Methamphetamine and Tobacco.
OBJECTIVE
Methamphetamine is a common illicit drug used worldwide. Methamphetamine and/or tobacco use by pregnant women remains prevalent. However, little is known about the effect of comorbid methamphetamine and tobacco use on human fetal brain development.


OBJECTIVE
To investigate whether microstructural brain abnormalities reported in children with prenatal methamphetamine and/or tobacco exposure are present at birth before childhood environmental influences.


METHODS
A prospective, longitudinal study was conducted between September 17, 2008, and February 28, 2015, at an ambulatory academic medical center. A total of 752 infant-mother dyads were screened and 139 of 195 qualified neonates were evaluated (36 methamphetamine/tobacco exposed, 32 tobacco exposed, and 71 unexposed controls). They were recruited consecutively from the community.


METHODS
Prenatal methamphetamine and/or tobacco exposure.


METHODS
Quantitative neurologic examination and diffusion tensor imaging performed 1 to 3 times through age 4 months; diffusivities and fractional anisotropy (FA) assessed in 7 white matter tracts and 4 subcortical brain regions using an automated atlas-based method.


RESULTS
Of the 139 infants evaluated, 72 were female (51.8%); the mean (SE) postmenstrual age at baseline was 41.5 (0.27) weeks. Methamphetamine/tobacco-exposed infants showed delayed developmental trajectories on active muscle tone (group × age, P < .001) and total neurologic scores (group × age, P = .01) that normalized by ages 3 to 4 months. Only methamphetamine/tobacco-exposed boys had lower FA (group × age, P = .02) and higher diffusivities in superior (SCR) and posterior corona radiatae (PCR) (group × age × sex, P = .002; group × age × sex, P = .01) at baseline that normalized by age 3 months. Only methamphetamine/tobacco- and tobacco-exposed girls showed persistently lower FA in anterior corona radiata (ACR) (group, P = .04; group × age × sex, P = .01). Tobacco-exposed infants showed persistently lower axial diffusion in the thalamus and internal capsule across groups (P = .02).


CONCLUSIONS
Prenatal methamphetamine/tobacco exposure may lead to delays in motor development, with less coherent fibers and less myelination in SCR and PCR only in male infants, but these abnormalities may normalize by ages 3 to 4 months after cessation of stimulant exposure. In contrast, persistently less coherent ACR fibers were observed in methamphetamine/tobacco- and tobacco-exposed girls, possibly from increased dendritic branching or spine density due to epigenetic influences. Persistently lower diffusivity in the thalamus and internal capsule of all tobacco-exposed infants suggests aberrant axonal development. Collectively, prenatal methamphetamine and/or tobacco exposure may lead to delayed motor development and white matter maturation in sex- and regional-specific manners.
Department of Medicine, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu.
Linda
L
Chang
Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Kenichi
K
Oishi
Department of Pediatrics, Sørlandet Hospital, Arendal, Norway4Department of Laboratory Medicine, Children's and Women's Health, Norwegian University of Science and Technology, Trondheim, Norway.
Jon
J
Skranes
Department of Medicine, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu.
Steven
S
Buchthal
Department of Medicine, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu.
Eric
E
Cunningham
Department of Medicine, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu.
Robyn
R
Yamakawa
Department of Medicine, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu.
Sara
S
Hayama
Department of Medicine, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu.
Caroline S
CS
Jiang
Department of Psychiatry, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu.
Daniel
D
Alicata
Department of Medicine, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu.
Antonette
A
Hernandez
Department of Medicine, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu.
Christine
C
Cloak
Department of Obstetrics, Gynecology and Women's Health, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu.
Tricia
T
Wright
Department of Medicine, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu.
Thomas
T
Ernst
D000014:Abnormalities, Drug-Induced / Q000000981:diagnostic imaging / Q000209:etiology*; D016022:Case-Control Studies; D015331:Cohort Studies; D002658:Developmental Disabilities / Q000139:chemically induced* / Q000000981:diagnostic imaging; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D013287:Illicit Drugs / Q000009:adverse effects*; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D008694:Methamphetamine / Q000009:adverse effects*; D009129:Muscle Tonus / Q000187:drug effects; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000187:drug effects; D009460:Neurologic Examination / Q000187:drug effects; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced* / Q000000981:diagnostic imaging; D011446:Prospective Studies; D012737:Sex Factors; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D066127:White Matter / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000187:drug effects*
D013287:Illicit Drugs; D014028:Tobacco Smoke Pollution; D008694:Methamphetamine