Official NHS guidance warns pregnant women not to smoke cigarettes because it can damage their baby. Those who feel they are unable to stop completely are advised to use nicotine replacement therapy, such as patches or tablets. But the latest research, published in the Journal of Physiology, however, found that nicotine in any form may increase the risk of sudden infant death.
Cot death or sudden infant death syndrome, is the unexpected death of an apparently healthy child under the age of 12 months, typically during sleep.
In a study on rats, the researchers found that exposure to either cigarette smoke or e-cigarettes could impair a baby’s ‘gasp reflex’ – which automatically restarts breathing after a lack of oxygen. The researchers, from the Geisel School of Medicine at Dartmouth, New Hampshire, found the use of nicotine during pregnancy could elicit autoresuscitation defects in developing animals. They exposed rats to nicotine through maternal blood or milk and then looked at their response to repeated periods of severe low oxygen.
Smoking during pregnancy is still a major problem and despite decades of warnings, about 10 per cent of pregnant women still do it. It has been linked to miscarriage, premature birth, low birth weight and stillbirth.
The study’s authors state that, with rising number of women turning to nicotine patches and e-cigarettes to stop them smoking during pregnancy, there is an urgent need to gauge the impact of the nicotine these contain on a developing baby.
Researchers believe exposure of the mother to nicotine may damage the baby’s central nervous system and impair the gasp reflex, also known as autoresuscitation. When a baby is suffering from a severe lack of oxygen – for instance after getting tangled in bedding, suffering a minor illness or having a blocked airway – the failure to start gasping for air can be fatal.
The authors suggest that using nicotine in forms such as patches or electronic cigarettes is not a safe alternative to cigarettes during pregnancy, because exposure to nicotine by any route may be harmful to a baby’s cardiorespiratory function and increase the risk of sudden death.
Study author Stella Lee said: ‘Sudden infant death syndrome is such a distressing tragedy for families. We still don’t fully understand the causes, but this research is important because it helps mothers reduce the risk.’
Aihua Li, senior author on the project, added: ‘We will continue to identify the possible predictors of risk and consider how we can treat infants who have a compromised autoresuscitation mechanism.
Dr Nick Hopkinson, medical advisor to the British Lung Foundation said: ‘Smoking during pregnancy is harmful to both mother and baby, so it’s important to quit.
‘Alternative sources of nicotine like nicotine replacement therapy (NRT) are much safer than smoking and help women to avoid most of the harm that comes from inhaling tar and carbon monoxide. ‘There may be some risk from nicotine by itself, but we know from clinical trials in people, that the children of women who smoke who are given NRT during pregnancy have better outcomes than those who aren’t. If women are concerned they should talk to their doctor or midwife.’