London, Feb 27 (IANS): Financial incentives could help one in five women quit smoking during pregnancy, shows a new research.

Only a small number of women 'gamed' the system to receive the incentives while continuing to smoke.

While the prevalence of smoking in pregnancy has declined, it remains high amongst more socially deprived groups.

"We all know of the dangers of smoking, particularly during pregnancy, but quitting can be extremely difficult. Offering financial incentives clearly works for some women - with very few 'gaming' the system and a significant number stopping smoking at least for the duration of their pregnancy," said Theresa Marteau, professor from the University of Cambridge and lead author.

To assess the potential effectiveness of financial incentives and inform their use in clinical practice, a study was carried out on 239 pregnant women who were enrolled into the financial incentives scheme.

At each visit to the clinic, the women were asked if they had smoked since the last visit and were given a breath test.

If they had not smoked, they were given a shopping voucher, the value of which was increased for subsequent visits.

Testing positive for smoking resulted in the incentive being withheld at that visit.

Of the women who enrolled in the scheme, 143 received at least one voucher, suggesting that they had attempted to quit.

One in five of the women (48 women) had managed to quit by the time of delivery.

In all cases, women from areas of highest deprivation were the least likely to succeed in quitting.

"Smoking is very addictive and these women have done incredibly well to quit. The incentive scheme gave them that bit of extra help that made all the difference," said Julie Hirst, public health principal at Derbyshire County Council.

The study was published in the journal Addiction.