It is widely known that smoking during pregnancy may cause harm to offspring. But new research from Western University in Canada suggests that women who use nicotine replacement therapy during pregnancy in an attempt to quit the habit may still be putting their child at risk of obesity and metabolic syndrome.
The research team, led by Daniel Hardy of the Schulich School of Medicine and Dentistry at Western University, published the study findings online in the journal Toxicology and Applied Pharmacology.
According to the US Centers for Disease Control and Prevention (CDC), smoking during pregnancy is linked to an increased risk of miscarriage, preterm birth, sudden infant death syndrome (SIDS) and cleft lip.
Last year, Medical News Today reported on a study suggesting that smoking during pregnancy may increase a female infant's risk of gestational diabetes and obesity.
The researchers note that in their study, they wanted to determine if there was a biological link between nicotine exposure from either smoking or nicotine replacement therapy (NRT), and metabolic syndrome and obesity later in the offspring's life.
NRT is the administration of nicotine into the body by means other than the use of cigarettes, in an attempt to quit smoking.
The US Food and Drug Administration (FDA) have approved five types of NRT. These include nicotine patches, gum, nasal spray, inhalers and lozenges.
Fetus nicotine exposure 'increases triglyceride production'
For their study, the investigators conducted an experiment on pregnant laboratory rats.
The pregnant rats were given 1 mg of nicotine for each kg of their weight each day - the equivalent to the same amount of nicotine an average smoker has each day. The offspring of the rats were monitored for 6 months after birth.
The researchers note that the amount of nicotine the pregnant rats were given is significantly less than the amount of nicotine found in NRT, which is 10 mg or the equivalent to 10 cigarettes.
Researchers say although giving up smoking during pregnancy is positive, undergoing nicotine replacement therapy while pregnant may increase a child's risk of obesity.
When the rat pups were born, the investigators say they were smaller in size compared with rat pups born to mothers who were not exposed to nicotine.
But even more importantly, when the pups reached 6 months of age, they developed an increase in liver and circulating triglycerides - a compound that helps the transference of blood glucose and adipose fat from the liver. Triglycerides are also an indicator of obesity.
The researchers also found that triglyceride production is increased when a liver is exposed to nicotine long-term.
Hardy says that because animal studies have shown folic acid can reduce circulating triglycerides, he would like to determine whether increasing doses of folic acid during pregnancy could reverse or prevent the liver from nicotine damage.
Although Hardy agrees that NRT is still better for pregnant women than smoking, he stresses that there needs to be further investigation into the long-term safety and effectiveness of this therapy during pregnancy, and the effect it may have on postnatal health and wellbeing of offspring.
Last year, Medical News Today reported on a study suggesting that mothers who smoke during pregnancy are more likely to have children with conduct disorder.