Passive Smoking

Sudden infant death syndrome is the nightmare of every parent, and the connection with maternal cigarette smoking is well known. To examine the effects of maternal smoking on apnea and arousal, Sawnani and colleagues performed polysomnographic studies in preterm infants. Sixteen infants of smoking mothers and 14 control infants underwent detailed polysomnography over a single night, scored independently by two blinded observers. Mean gestational age was younger than 30 weeks for both groups. The infants spent a mean of just over 8 weeks in the neonatal intensive care unit. Maternal smoking history was from a questionnaire, which might lead to smokers being included in the control group, lessening the power of the study and thus making it more likely that significant findings are real. Prenatal smoke exposure led to a more than doubling of the apnea index in active sleep, with a 2.5-fold increase in obstructive events. There was a 25% reduction in arousal index in the babies exposed to smoke prenatally, and specifically, there were only a third of the arousals after apneic events, suggesting a worrying increase in arousal threshold. The authors suggested that this combination of increased likelihood of obstructive apnea and reduced response may underlie the increased risk of sudden infant death in those born preterm to smoking mothers.

Hoo and colleagues compared lung growth and development during the first year of life in healthy term infants of low or appropriate birth weight for gestation. Paired measurements of FEV in 0.4 second, FVC, and forced expiratory flow when 75% of FVC has been exhaled were obtained, using the raised volume technique, at approximately 7 weeks and 9 months of age in 80 infants (32 low and 48 appropriate birth weight for gestation) of white, nonsmoking mothers. Forced flows and volumes increased with growth. After adjustment for sex, age, and length, FEV was significantly reduced by an average (95% CI) of 9% (2–16%) in low birth weight compared with appropriate birth weight for gestation infants throughout the first year of life, with a similar trend in forced expiratory flow (8% [–2–17%]) and FVC (4% [–3–11%]). These findings suggest that lung function is reduced in low birth weight for gestation infants born to nonsmoking, white mothers and that this is independent of somatic growth during infancy.

Citations 1-2 of 2 total displayed.

Development of Lung Function in Early Life: Influence of Birth Weight in Infants of Nonsmokers

Ah-Fong Hoo, Janet Stocks, Sooky Lum, Angie M. Wade, Rosemary A. Castle, Kate L. Costeloe, and Carol Dezateux
Am. J. Respir. Crit. Care Med. 170: 527 -533. First published online as doi:10.1164/rccm.200311-1552OC [Abstract] [Full text]

The Effect of Maternal Smoking on Respiratory and Arousal Patterns in Preterm Infants during Sleep

Hemant Sawnani, Tonya Jackson, Thomas Murphy, Robert Beckerman, and Narong Simakajornboon
Am. J. Respir. Crit. Care Med. 169: 733 -738. First published online as doi:10.1164/rccm.200305-692OC [Abstract] [Full text]

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