Toronto, Jan 17 (IANS): Pregnant women who shift to alternate form of nicotine in gums, nasal sprays or lozenges do not do any good to the little bundle of joy inside, warns a new study.

Researchers from Western University in London city in Canada found that nicotine from either smoking or nicotine replacement therapy (NRT) causes a wide range of long-term adverse reactions for the offspring - including an increased risk of obesity and metabolic syndrome.

“We know smoking is bad during pregnancy. Studies have shown that babies born to smoking mothers have a 47 percent increase in the odds of becoming overweight,” said Daniel Hardy, assistant professor in departments of obstetrics and gynaecology at Western University.

“Our studies were designed to find if there is a biological basis between nicotine exposure from either NRT or smoking, and obesity and metabolic syndrome later in the offspring’s life,” added Hardy.

Working in collaboration with Alison Holloway of McMaster University, Hardy gave pregnant rats same amount of nicotine - adjusted for the weight - that an average smoker receives (1 mg per kg a day).

The offspring were born smaller in size but six months later when they reached adulthood, the rats had developed an increase in liver and circulating triglycerides - a hallmark of obesity, said the study published in the journal Toxicology and Applied Pharmacology.

The study also demonstrated that the nicotine-exposed liver was making more triglycerides.

Hardy, however agrees that compared to smoking, NRT is the lesser of two evils.

“But clinicians may need to look more closely at the long-term safety and efficacy of nicotine in pregnancy on postnatal health and well-being,” Hardy added.

Women who smoke are encouraged to quit smoking when they become pregnant using nicotine replacement therapy (NRT), often in the form of gum, transdermal patches, nasal spray or lozenges.