Abstract
Aim: Cigarette smoking in pregnancy can adversely affect infant respiration after birth. For instance, in-utero nicotine exposure blunts the infant ventilatory response to hypercapnia, thereby increasing the risk of sudden infant death syndrome. The potential impact of other types of nicotine exposure during pregnancy, such as second-hand smoke, however, is not yet fully understood. We aimed to investigate the impact of second-hand smoke exposure during pregnancy on infant ventilatory response compared to infants of cigarette-smoking and non-smoking mothers.
Methods: A prospective cohort study of term infants was conducted on the postnatal ward. Infants breathed through a face mask and specialised “tube-breathing” circuit, incorporating a deadspace of 4.4mls/kg bodyweight (twice the anatomical deadspace) to induce transient hypercapnia. A pneumotachograph recorded ventilatory parameters. The maximum minute ventilation (MMV) during added deadspace breathing was determined, and the time taken to achieve 63% of the MMV calculated.
Results: Twenty-nine infants were studied (median gestational age=39.2 weeks [range 37.2-41.5]; birthweight=3.1kg[2.2-4.0]). The median MMV was significantly raised in infants of smoking mothers (n=9;703.5 ml/min/kg [336.8-1329.7]; p=0.025) and infant exposed to second-hand smoke (n=10;695.8[379.9-941.6]; p=0.021) in comparison to controls (n=10;534.7ml/min/kg[346.7-709.1]). Infants of smoking mothers displayed a trend to take longer to achieve 63% of the MMV (36.3s[1.2-59.5]) than infants exposed to second-hand smoke (21.4s[8.9-75.7]) and controls (15.1s[8.1-32.5]).
Conclusion: Enviornmental tobacco smoke exposure during pregnancy may have significant effects on newborn respiration.
Footnotes
Cite this article as Eur Respir J 2022; 60: Suppl. 66, 2692.
This article was presented at the 2022 ERS International Congress, in session “-”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
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