Previous studies have shown that babies exposed to tobacco in utero are more likely to have a low birth weight and are at increased risk for sudden infant death syndrome.
Now new research by The Miriam Hospital reveals that these babies are also less likely to self-soothe and are more aroused and excitable than newborns whose mothers did not smoke during pregnancy.
Researchers from The Miriam Hospital's Centers for Behavioral and Preventive Medicine say early identification and targeted intervention efforts aimed at both infants and parents may help prevent possible disruption in early maternal-infant bonding and, ultimately, long-term adverse outcomes. The study is published online by the Journal of Pediatrics .
"A baby who is harder to soothe and more irritable could be more difficult to take care of and could potentially affect the developing mother-child relationship, especially for mothers who are already stressed and have fewer resources," says lead author Laura Stroud, PhD, a psychologist with The Miriam Hospital's Centers for Behavioral and Preventive Medicine. "We need better treatment programs to help women not smoke during pregnancy, to keep them from starting smoking after the baby is born, and to help them take care of an excitable or colicky baby."
Between 11 and 30 percent of women continue to smoke during pregnancy, according to the Centers for Disease Control and Prevention. In addition to the physical side effects, tobacco exposure in utero has also been linked to long-term adverse neurobehavioral outcomes in children, including conduct disorder and hyperactivity. However, researchers say relatively less attention has focused on the effects of maternal smoking on newborn neurobehavior.
In the study, Stroud and colleagues from Women & Infants Hospital in Providence, RI, and the Warren Alpert Medical School of Brown University focused on newborns between 10 and 27 days old. The researchers decided on this infant age range because it is well past the half-life of nicotine, meaning the acute effects of nicotine withdrawal were unlikely to be a factor in the study. All 56 babies – 28 smoking-exposed and 28 unexposed – were healthy and full-term. Maternal social class, age and alcohol use were similar in each group.