Smoking is one of the toughest habits to break but many women find that pregnancy gives added incentive to kick the habit. Some turn to nicotine replacement therapy (NRT) to ease the transition to becoming a non-smoker and others use NRTs to reduce their intake of nicotine and other harmful elements in cigarettes. A recent study, however, indicates NRTs may not be such a safe option after all.

The US Food and Drug Administration (FDA) regulates the manufacture and sale of NRT products. There are five NRT delivery systems available on the market today: gum, inhalers (including e-cigarettes), lozenges, nasal spray, and nicotine patches. Some NRTs are available by prescription only and others are sold over the counter. Some consumers limit use to just one form but others prefer a combination.

Various studies in recent years find links between smoking during pregnancy and a number of health concerns affecting the pregnancy and the children born to smokers. Some of these health concerns include increased risk of:


Daniel Hardy led the study of the effects of NRT use during pregnancy. Hardy and his team are based at the Schulich School of Medicine and Dentistry at Western University in London, Ontario.

Hardy’s team used laboratory rats for their tests since they respond in ways metabolically similar to humans but their much-shorter lifespan makes it possible to study generational effects much more quickly.

Each pregnant lab rat was given 1 milligram (mg) of nicotine for each kilogram (kg) of its body weight. This nicotine dose is equivalent to what an average human smoker consumes each day. The rats’ overall daily dosage of nicotine was significantly less than the 10mg of nicotine in NRTs. The nicotine in 10 cigarettes is equivalent to 10mg, according to the research team.

The rat pups born during the experiment were monitored for six months. Those exposed to nicotine in the womb were smaller at birth than those in a control group of pregnant rats that were not given nicotine. By six months of age, they began to exhibit symptoms of increased levels of triglycerides in the liver and bloodstream. Elevated levels of triglycerides are a clinical indicator of obesity, putting these pups at higher risk of developing metabolic syndrome and obesity than those in the control group.

Hardy acknowledges the benefit of reduced exposure to nicotine when a woman uses NRTs during pregnancy rather than smoking but says further study is needed to assess long-term safety and effectiveness of NRT use during pregnancy.

Source: Whiteman, Honor. “Nicotine replacement in pregnancy linked to offspring obesity.” Medical News Today. MediLexicon International Ltd. Jan 19, 2014. Web. Jan 24, 2014.