Newborn babies exposed to nicotine through active and passive smoking have poor physiological, sensory, motor and attention responses, researchers from the Rovira i Virgili University have found.
"Newborns who have had intrauterine exposure to nicotine, whether in an active or passive way, show signs of being more affected in terms of their neurobehavioural development," said Josefa Canals, a researcher at the Rovira i Virgili University.
Researchers studied the health of more than 280 healthy newborns and the smoking habits of 282 mothers during pregnancy. Among the 282 mothers, 22% smoked during pregnancy. Of the smoking mothers, 12.4% had between 1 and 5 cigarettes a day; 6.7% had between 6 and 10 a day; and 2.8% had between 10 and 15 a day. None of them smoked more than 15 cigarettes a day.
Then, just 48 to 78 seconds after birth, researchers evaluated the behaviour of 282 healthy newborns using the Neonatal Behavioural Evaluation Scale. This allows for interaction with the newborn in order to evaluate its behaviour and responses.
The study found that babies born to smoking and passive smoking mothers score low in their ability to inhibit stimuli that could alter the central nervous system.
In addition, children of passive smoking mothers have poor motor development and those of smoking mothers have less ability to regulate behaviour and response in physiological, sensor, motor and attention terms, according to findings published in the Early Human Development journal.
According to the study, smoking during pregnancy is one of the biggest yet preventable causes of illness and death for both mother and infant. Epidemiological studies show that between 11% and 30% of pregnant women smoke or are passively exposed to tobacco smoke.
When a pregnant woman smokes, nicotine concentrations in the foetus reach more than 15% that of the mother.
"However, although women tend to reduce their normal tobacco consumption when falling pregnant, the key is to study the effects of exposure to small amounts of smoke on foetal development," said Canals.
Previous studies had found that smoking during pregnancy can cause several problems in infants like learning difficulties, attention deficit disorder with hyperactivity and even obesity, but now they have found it can also cause neurodevelopment problems.
"Health professionals should encourage future mothers and their families to eliminate or reduce tobacco consumption," said Canals.