​Red Nose recommends: Keep baby smoke free before birth and after.

  • Smoking in pregnancy increases your baby’s risk of death during pregnancy and up to one year of age
  • There is an increased risk of sudden unexpected death for babies exposed to tobacco smoke during pregnancy and after birth
  • If baby’s father smokes there is also an increased risk of SUDI
  • The risk of SUDI is increased for babies who share a sleep surface with a person who smokes, even if the smoker doesn’t smoke in the bed
  • Do not let anyone smoke near your baby.
  • Keep breastfeeding baby even if you are a person who smokes

Babies who are exposed to tobacco smoke before and after birth are at an increased risk of SUDI. To avoid exposing your baby to tobacco smoke, don’t let anyone smoke near your baby - not in the house, the car or anywhere else your baby spends time.

It is often hard to quit smoking so ask for help. Call the Quitline on 137 848 or ask your doctor, midwife or child health nurse for information and advice about quitting.

Evidence: effects of smoking

Babies and young children are especially vulnerable to the poisons in second hand smoke because their bodies are developing.1 Babies of mothers who smoke or who are exposed to second hand smoke are more likely to be born prematurely and be of low birth weight.2,3 Specific effects of passive smoking on babies and children include SUDI, respiratory infections and conditions including croup, bronchitis, and pneumonia; ear infections; learning difficulties; behavioural problems including increased infant irritability and hypertonicity, and an increased likelihood of childhood asthma.1,4,5

Prenatal smoking increases the risk of stillbirth,6-9 neonatal mortality (death of a live-born baby within 28 days10) and infant mortality.9 Importantly, new research has shown that in mothers who stopped smoking before 15 weeks of pregnancy there was no increased risk of preterm delivery or the baby being born small for gestational age compared to those mothers who never smoked. 11

An increased risk of SIDS when babies are exposed to tobacco smoke both during pregnancy and after birth has been found in numerous epidemiological, case-control and cohort studies from around the world.12 A large case-control study in the United Kingdom involving families with babies born during the period 1993-1995, since the change in sleeping position was promoted, found that the incidence of smoking during pregnancy was significantly greater in mothers of 195 SIDS cases (63%) than in mothers of 780 controls (25%).13 This finding is consistent over time and country. A recent meta-analysis of 35 case-control studies reported a dose-response relationship, meaning that the more cigarette smoke the baby is exposed to, the higher the risk of sudden infant death.12

Co-sleeping (sleeping on the same sleep surface) with an infant greatly increases the risk for SIDS if the mother smokes and if both parents smoke.12,14

Several studies have identified that babies exposed to maternal smoking before and after birth do not arouse as readily as babies who were not exposed.15 It is really important that babies can arouse readily from sleep so they can respond by swallowing or gasping if a life-threatening event occurs (for example if the time between breaths is really long, there is fluid in the throat, or there is a sudden fall in blood pressure). It is currently thought that a failure to arouse from sleep contributes to the final pathway to SIDS16. Babies exposed to maternal smoking before birth have been shown to have disrupted sleep patterns,17 increased irritability5 and decreased control of heart rate.18

Smoking is one of the most important modifiable risk factors in reducing the risks of sudden infant death with international agreement that the evidence now demonstrates a causal association.19 A recent study from the USA has reported that with increased public awareness of maintaining infants in a smoke free environment there were potentially 534 fewer infant deaths attributable to second hand smoke between 1995 and 2006.20

Smoking and breastfeeding

Breast feeding has been shown to be protective for SIDS by approximately 50% at all ages throughout infancy,21 and advice to breastfeed is an important SIDS risk-reduction message. A case-control study of the nicotine and cotinine (a metabolite of nicotine) levels in the body fluids and hair of babies who had died from SIDS found that the babies of mothers who reported having smoked during pregnancy had higher nicotine levels than the babies of non-smoking mothers. The authors then looked at the way the babies were fed and found that the cotinine and nicotine levels were not significantly higher in the breast fed babies of smoking mothers compared to those who did not smoke, suggesting that the transfer of nicotine and cotinine in breast milk was not a significant factor and that passive smoking was the major cause of the observed high levels.22

All mothers, including those who smoke, are encouraged to breastfeed their babies.

Bed-sharing and co-sleeping if you or your partner smoke

Red Nose recommends sleeping a baby in a cot next to the parents’ bed (room-sharing) for the first six to twelve months of life as this has been shown to lower the risk of SUDI and this is also the case for babies in families where one or both parents smoke.

Sharing a sleep surface with a baby (co-sleeping or bed-sharing) can increase the risk of SUDI and a considerable proportion of SUDI occur on a shared sleeping surface. There is a much greater risk for SIDS if the mother smokes or if both parents smoke, and share a sleep surface with a baby.12,14 This is particularly important for young babies under 3 months of age,23 with one large meta-analysis showing the increased risk for babies of 2 weeks of age was 65 times more likely, 28 times more likely at 10 weeks of age and 10 times more likely at 20 weeks of age if both parents smoke.14

What about paternal smoking and smoking among other members of baby’s household?

If fathers are smokers then there is an independent additive increase in the risk of SIDS.24

An independent effect of postnatal exposure to tobacco smoke has been found in a number of studies as well as a dose response for the number of household smokers, people smoking in the same room as the baby, number of cigarettes smoked, and daily hours the baby is exposed to a smoke-filled environment.1-3, 25-26

A recent study shows that both mothers’ and fathers’ tobacco smoke make substantial contributions to baby’s exposure to tobacco smoke. All passive smoking that a baby is exposed to may increase the risk of SUDI.27 All carers and family members have a role in reducing the exposure of the baby to tobacco smoke and thereby reducing baby’s risk of SUDI.

Efforts to minimise baby’s exposure to tobacco smoke

Research has shown that protecting babies from fathers’ as well as mothers’ smoking is key in reducing environmental tobacco exposure in early infancy, when the risk of SUDI is highest.27 A number of studies have examined ways to achieve this. Strategies such as keeping windows open and avoiding smoking near the baby are not completely effective in reducing an baby’s exposure to tobacco smoke 28 and cotinine concentrations in the hair of the children of parents who smoke were strikingly similar whether the parent stated that they smoked indoors or outside.29-31 Although going outside to smoke reduces a child’s exposure to Environmental Tobacco Smoke (ETS)31 giving up smoking is the most effective way of reducing ETS exposure for babies and children.28,32

Advice for those parents who do smoke

Room-sharing reduces the risk of sudden infant death33 while sharing a sleep surface with a baby if you are a smoker significantly increases the risk.26,33-40 The risk is much greater in younger infants.11,14 Babies of mothers who smoke are at a higher risk of SUDI than babies of mothers who do not smoke and room share.41 As room-sharing reduces the risk of SUDI, and babies of smokers are at an increased risk, current advice is that parents who are smokers should room-share (but not share the same bed or sleep surface) as long as the room baby sleeps in is kept smoke free.33

Breastfeeding reduces the risk of SUDI.21,42 Although smoking has been shown to decrease the duration of breast feeding,43-44 drawing from the findings of the New Zealand Cot Death Study, E.A. Mitchella (personal communication, 2015) stated that mothers who smoke are encouraged to breast feed their baby for as long as possible as there is no evidence that breast feeding is less protective for babies whose mothers smoke.

Incidence and intervention

In Australia, the proportion of women who smoked during pregnancy ranged from 7.8% in the ACT to 24.4% in the Northern Territory. Nationally, 12.5% of women smoked during pregnancy in 2012. This is a decline from 13.2% in 2011, 13.5% in 2010 and 15.5% in 2009.45 Almost half (48.1%) of First Nation mothers and over a third (34.9%) of teenage mothers smoked. Evidence from the UK suggests the prevalence of maternal smoking during pregnancy has risen amongst mothers whose baby’s death was attributed to SIDS (from 50% to 80%) when the rate amongst expectant mothers in the general population has fallen (from 30% to 20%), confirming estimates from recent studies of a four-fold increased risk of sudden infant death for the babies of parents who smoke.26

Legislation in all jurisdictions in Australia prohibits smoking in the vehicle when babies and young children are present.b Exposure to secondhand smoke in a vehicle is more toxic than in a house due to the smaller enclosed space.1,46 It is therefore very important to keep the car, as well as the home, a smoke free zone.

There is an extensive literature concerning the difficulties associated with smoking cessation and which interventions are most effective.2,3,19,38,42-45 It is generally agreed that although providing information is important, on its own it has little impact on smoking behaviour. Cognitive-behavioural strategies have been shown to be the most effective while reward programs with social support are supported by a limited number of studies.44 Health professionals involved in antenatal and postnatal care should ensure that they refer parents to such programs.

The 5As approach (Ask, Advise, Assess, Assist, Arrange) to smoking cessation should be incorporated into routine antenatal care in the form of a brief smoking cessation intervention (lasting approximately 3-5 minutes) for all pregnant women who are identified as smokers or recent quitters (have quit within the past 12 months) at each antenatal visit. More intensive counselling should be made available to pregnant women to aid a quit attempt and/or prevent relapse eg. Referral to Quitline.2,4,19,50

Support to quit smoking should also be provided to the women’s partner. 2,3,19,50

Post partum relapse prevention should begin in the antenatal period and continue after the birth of the baby at every opportunity, including routine postnatal health checks and through maternal and child health services.2,19

The Red Nose Safe Sleeping program is based on scientific evidence and was developed by Australian SUDI researchers, paediatricians, pathologists, and child health experts with input from overseas experts in the field. The 85% drop in SUDI deaths and the 9,967 lives that have been saved is testament to the effectiveness of the program.

For further information phone us on 1300 998 698.

Suggested citation:

Red Nose. National Scientific Advisory Group (NSAG). (2015). Information Statement: Smoking. Melbourne: Red Nose. The first edition of this information statement was posted in March, 2009.

View the references for this article here.

Last modified: 9/1/60