Smoking: quit by 15 weeks to reduce pregnancy complications
3 April 2009
Pregnant women who stop smoking by 15 weeks reduce their risk of having a preterm (premature) birth or delivering a small for gestational age (small for dates) baby to the same level as non-smokers, Australian research shows (BMJ, online first, March 2009).
However, those who continue to smoke after 15 weeks had 3 times the rate of preterm birth and almost double the rate of small for gestational age infants compared to those who stopped smoking.
Women who gave up smoking within 15 weeks did not have increased measures of stress, anxiety or depression.
The findings led the researchers to recommend all pregnant women receive lifestyle advice, including smoking cessation, at 10 weeks’ gestation.
Researchers tracked 2504 women through their first pregnancy. Of those, 80 per cent were non-smokers, 10 per cent ceased smoking and 10 per cent continued to smoke.
Professor Nick Zwar, of the school of public health at the University of NSW, said the finding provided women with reassurance that if they stopped smoking early in their pregnancy at least some potential harms could be avoided.
‘It’s especially useful for women who think the damage may have already been done [by 15 weeks], so why bother giving up,’ he said. ‘But advice should always be to give up, regardless of what stage in the pregnancy, and then to ensure they don’t relapse after the delivery.’
Last Reviewed: 03 April 2009
- 1. McCowan LM, Dekker GA, Chan E, et al. Spontaneous preterm birth and small for gestational age infants in women who stop smoking early in pregnancy: prospective cohort study. BMJ 2009 Mar 26; 338: b1081
