Control of breathing in infants born to smoking mothers,☆☆,,★★

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Abstract

Objective: To determine whether infants born to smoking mothers have an abnormal respiratory drive and a blunted ventilatory response to hypoxia. Study design: Sixty-four healthy infants, aged 2 to 24 months, were classified into smoking (n = 19) or non-smoking (n = 45) groups based on maternal smoking habits. Resting ventilation, lung function, and mouth pressure 100 milliseconds after an airway occlusion at the onset of inspiration (P0.1 ) were measured. The ventilatory response to hypoxia was assessed in 15 infants (6 in the smoking group and 9 in the non-smoking group) while breathing 14% oxygen. Results: Respiratory drive (P0.1 = 4.9 ± 1.3 cm H2 O) was lower in infants in the smoking group compared with those in the non-smoking group (P0.1 = 5.9 ± 1.2 cm H2 O) (P < .05). The time to peak tidal expiratory flow (tPTEF) was also shorter (0.25 ± 0.04 seconds vs 0.32 ± 0.09 seconds, P < .05). Infants born to non-smoking mothers showed a significant ventilatory response to hypoxia and a 24.6% increase in P0.1 . Infants in the smoking group showed a blunted ventilatory response to hypoxia and no increase in P0.1 . A dose-response relationship existed between the number of cigarettes smoked by the mother (0, 1 to 10, >10 per day) and the results for P0.1 and tPTEF. Paternal smoking had no influence on the infant’s resting ventilation, respiratory drive, or ventilatory response to hypoxia. Conclusions: Infants born to smoking mothers have a reduced drive to breathe and a blunted ventilatory response to hypoxia. These findings may contribute to the increased risk of sudden infant death syndrome in these infants. (J Pediatr 1999;135:226-32)

Section snippets

Subjects

Sixty-four healthy term infants, aged 2 to 24 months (mean age, 11.6 ± 6.5 months) were studied. Subjects were recruited for the study through an advertisement in local child health centers in Perth, Western Australia. The hospital ethics committee approved the study, and parents gave written consent. Thirty-five sets of parents in this study were lifetime non-smokers. In 10 families only the father smoked and in 6 only the mother smoked. In the remaining 13 families both parents smoked.

RESULTS

Infants were divided into 2 groups, the smoking group and the non-smoking group, by the maternal smoking history assessed by a questionnaire. Nineteen mothers smoked during their pregnancy, with 10 mothers smoking less than 10 cigarettes per day and 9 mothers smoking more than 10 per day. All mothers who had smoked during the pregnancy continued smoking after the delivery. All mothers who smoked did so inside the house. In the 10 families in which only the father smoked, 4 fathers reported

DISCUSSION

The results of this study show that infants born to smoking mothers have a lower respiratory drive, as assessed by P0.1 . While breathing quietly in room air, these infants achieved normal ventilation but with an altered shape to the expiratory limb of their tidal flow-volume curve. However, unlike infants born to non-smoking mothers, when they were exposed to the hypoxic gas mixture, they had significantly blunted ventilatory responses.

We studied infants while sedated with chloral hydrate, as

References (24)

  • J Grenhoff et al.

    Pharmacology of nicotine

    Br J Addict

    (1989)
  • EA Mitchell et al.

    Risk factors for sudden infant death syndrome following the prevention campaign in New Zealand

    Pediatrics

    (1997)
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    From the Division of Clinical Sciences, TVW Telethon Institute for Child Health Research, Perth, Western Australia; Department of Respiratory Medicine, Princess Margaret Hospital for Children, Perth; University Department of Paediatrics, University of Western Australia, Perth, Australia.

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    Supported in part by grant No. 970164 National Health Medical Research Council, Australia.

    Reprint requests: Peter D. Sly, MD, Head, Division of Clinical Sciences, TVWT Institute for Child Health Research, PO Box 855, West Perth 6872, Western Australia, Australia.

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