According to research conducted by the British Market Research Bureau, in 2005 nearly a third (32%) of mothers in England smoked in the 12 months before or during pregnancy. Although nearly half (49%) gave up before the birth, three in ten (30%) were smoking again less than a year after giving birth. One in six (17%) continued to smoke throughout their pregnancy – one in ten (11%) of them cut down the amount they smoked (British Market Research Bureau 2007).
However, other research (including studies which had biochemically validated smoking status) suggests that the proportion of women smoking before or during pregnancy is higher than this (French et al. 2007; Lawrence et al. 2005; Owen and McNeill 2001). In addition, studies using biochemical measures of exposure to tobacco smoke suggest that their intake of toxins is not actually reduced – even when they said they had cut down (Lawrence et al. 2003).
In 2005, almost four in ten mothers in England (38%) lived in a household where at least one person smoked during their pregnancy. In most cases the person who smoked was the mother's partner. A sizeable minority did give up after the woman gave birth: 15% were not smoking when the baby was aged 4–10 weeks and by the time the baby was aged 4–6 and 8–10 months almost a quarter (24%) had quit (British Market Research Bureau 2007).
Almost half of all children in the UK are exposed to tobacco smoke at home (Jarvis et al. 2000).
Smoking during pregnancy can cause serious pregnancy-related health problems. These include: complications during labour and an increased risk of miscarriage, premature birth, still birth, low birth-weight and sudden unexpected death in infancy (Royal College of Physicians 1992). Smoking during pregnancy also increases the risk of infant mortality by an estimated 40% (Department of Health 2007).
The total annual cost to the NHS of smoking during pregnancy is estimated to range between £8.1 and £64 million for treating the resulting problems for mothers and between £12 million and £23.5 million for treating infants (aged 0–12 months) (Godfrey et al. 2010).
Children exposed to tobacco smoke in the womb are more likely to experience wheezy illnesses in childhood. In addition, infants of parents who smoke are more likely to suffer from serious respiratory infections (such as bronchitis and pneumonia), symptoms of asthma and problems of the ear, nose and throat (including glue ear). Exposure to smoke in the womb is also associated with psychological problems in childhood such as attention and hyperactivity problems and disruptive and negative behaviour (Button et al. 2007). In addition, it has been suggested that smoking during pregnancy may have a detrimental effect on the child's educational performance (Batstra et al. 2003).
Smoking during pregnancy is strongly associated with a number of factors including age and social economic position.
Mothers aged 20 or under are five times more likely than those aged 35 and over to have smoked throughout pregnancy (45% and 9% respectively) (British Market Research Bureau 2007). Mothers in routine and manual occupations are more than four times as likely to smoke throughout pregnancy – compared to those in managerial and professional occupations (29% and 7% respectively) (British Market Research Bureau 2007).
Pregnant women are also more likely to smoke if they are less educated, live in rented accommodation and are single or have a partner who smokes.
Almost nine in ten mothers (87%) who were smoking before or during their pregnancy said they received some type of advice or information about the habit (British Market Research Bureau 2007).
Mothers who had only been advised to give up were much more likely to quit – compared with those who were advised to cut down (36% and 8% respectively). Mothers who were only advised to cut down were more likely to take this option (69%) – less than 1% tried to quit. Mothers who received mixed messages (to stop completely and cut down) were much more likely to cut down rather than give up completely (58% and 14% respectively) (British Market Research Bureau 2007). In addition, women with partners who smoke find it harder to quit and are more likely to relapse if they do manage to quit (Fang et al. 2004).