Low-level prenatal exposure to nicotine and infant neurobehavior.
OBJECTIVE
To examine the association between prenatal exposure to nicotine from tobacco smoke and infant neurobehavior using tobacco biomarkers and a sensitive and comprehensive measure of infant neurobehavior.


METHODS
Participants were 318 infants (206 White, 95 Black, 17 Other) and their mothers. Prenatal tobacco smoke exposure was measured twice during pregnancy and once at delivery using maternal serum cotinine. Infant neurobehavior was assessed with the NICU Network Neurobehavioral Scale at approximately 5 weeks after birth.


RESULTS
Prenatal tobacco smoke exposure was significantly associated with infant neurobehavior after controlling for important covariates, but the specific behaviors associated with exposure varied by race. In White infants, higher cotinine was associated with increased arousal (p=.030) and excitability (p=.034), and decreased self-regulation (p=.010). In contrast, among Black infants, higher cotinine was associated with decreased arousal (p=.001), excitability (p=.021), and special handling required to complete the assessment (p=.003), and increased self-regulation (p=.021) and hypotonicity (p=.016). In secondary analyses, we found racial differences in the effects of postnatal exposure to second hand smoke and low-level prenatal exposure.


CONCLUSIONS
Low-level prenatal tobacco smoke exposure is associated with infant neurobehavior at 5 weeks of age, but the specific effects differ by race. These effects may reflect racial differences in nicotine metabolism that are similar to differences reported in adult and child studies of tobacco.
Yolton
Kimberly
K
Cincinnati Children's Hospital Medical Center, Department of Pediatrics, Division of General and Community Pediatrics, Cincinnati, Ohio 45229-3039, USA. kimberly.yolton@cchmc.org
Khoury
Jane
J
Xu
Yingying
Y
Succop
Paul
P
Lanphear
Bruce
B
Bernert
John T
JT
Lester
Barry
B
D000328:Adult; D001741:Black or African American; D001143:Arousal / Q000187:drug effects*; D015415:Biomarkers / Q000097:blood; D003367:Cotinine / Q000097:blood; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects*; D008431:Maternal-Fetal Exchange; D009123:Muscle Hypotonia / Q000139:chemically induced*; D009538:Nicotine / Q000633:toxicity*; D011247:Pregnancy; D012927:Social Control, Informal; D044465:White People
D015415:Biomarkers; D009538:Nicotine; D003367:Cotinine