(RxWiki News) It may not be enough to toss the cigarettes when pregnant. A new study reveals a baby's exposure to nicotine even through replacement therapies like the patch may mean trouble later.
Although a link had already been established through previous research between smoking and colic, doctors did not know much about the reasons. A new study reveals that nicotine may be the culprit.
"Don't use any form of nicotine while pregnant."
Dr. Ioanna Milidou, M.D., of the Department of Pediatrics at Herning Regional Hospital in Denmark, led the study using data from participants in the Danish National Birth Cohort, which ran from 1996 to 2002.
The researchers interviewed 63,128 mothers during pregnancy and when their children were six months old.
Just 0.3 percent of the infants had been exposed to some form of nicotine replacement therapy alone, and another 2 percent were exposed to nicotine replacement therapy as well as smoking.
The majority of children, 74 percent, were not exposed at all to nicotine during the pregnancy, and 24 percent of the babies had mothers who smoked during pregnancy.
The researchers found that 8 percent of the infants had colic according to the clinical definition: intense, unexplained, nonstop crying for more than three hours a day, more than three days a week for more than three weeks.
Nicotine was found to be associated with a higher risk of colic, even more so with the nicotine replacement therapy. Babies exposed to nicotine by this method or exposed to both the replacement therapy and smoking were 60 percent more likely to have colic than the babies with no nicotine exposure.
Mothers who smoked were 30 percent more likely to have babies with colic than mothers who didn't use any form of nicotine.
The researchers also considered smoking in the mother's environment by calculating the effects of her partner's smoking. They found no association with increased risk for colic after adjusting for the mother's tobacco use.
The researchers therefore concluded that "nicotine may play a role in the pathogenesis of infantile colic."
Colic has mystified doctors for years. Among the many theories about its cause are gastrointestinal issues, an inability to adapt to being out of the womb and overstimulation. No cure currently exists for it, but it usually fades by the fourth or fifth month of a baby's life.
The study appeared online February 20 in the journal Pediatrics. Milidou's Ph.D. scholarship was funded by the Health Research Fund of Central Denmark Region, Aarhus University and the Department of Paediatrics at Herning Regional Hospital.
The Danish National Birth Cohort was established by the Danish Epidemiology Science Centre, funded by the Danish National Research Foundation. Other funders to the cohort include the Pharmacy Foundation, the Egmont Foundation, the March of Dimes Birth Defects Foundation, the Augustinus Foundation and the Health Foundation.
The authors declared no competing financial interests.