Risk factors

Teenage births

Teenage motherhood poses significant long-term risks for both mother and child, including poorer health, educational and economic outcomes.

1 in 25 live births in Australia in 2009 were to teenage mothers.

Babies born to teenage mothers have an increased risk of pre-term birth, low birthweight and associated complications. Teenage mothers are more likely to be a lone parent, live in areas of greater disadvantage, smoke and have lower levels of education. While not all teenage births result in negative outcomes for mother and child, the factors that often contribute to teenage birth mean that many young mothers do not receive the support they need during pregnancy and after the birth.

How many children are born to teenager mothers? 

In 2009, about 11,700 babies were liveborn to teenage mothers. Most teenage births (83%) were to first-time mothers (excludes data for Victoria). The rate of live births per 1,000 females aged 15–19 fell slightly from 17 in 2008 to 16 in 2009.

Do rates of teenage births vary across population groups? 

The birth rate among Indigenous teenagers was more than 5 times the non-Indigenous rate (72 compared with 14 per 1,000 females aged 15–19). The rate among all teenagers increased with geographical remoteness, rising from 12 per 1,000 in Major cities to 57 in Remote and very remote areas.

The rate among teenagers living in the most socioeconomically disadvantaged areas was almost 8 times that of teenagers living in the areas of least disadvantage (30 compared with 4 per 1,000).

Among women born overseas, the teenage birth rate was around one-third lower than for Australian-born women (12 compared with 18 per 1,000).

How does Australia compare internationally? 

According to the Organisation for Economic Co-operation and Development (OECD) Family Database, Australia’s 2008 teenage birth rate of 15 live births per 1,000 females was slightly ahead of the OECD average (16), but substantially higher than Switzerland (4.3), Japan and Italy (4.8 each).

Teenage birth rate by selected population groups, 2009

 

(a) Indigenous status of mother.

Notes
1. Data for 2009 are not final. Provisional data were provided by Victoria for 2009.
2. Refer to A picture of Australia’s Children 2012, Appendix B: Methods for explanation of remoteness areas and socioeconomic status (SES).

Source: AIHW National Perinatal Data Collection.

Smoking in pregnancy

Smoking during pregnancy is a significant risk factor for the mother and her unborn baby. It increases the risk of a range of conditions, including low birthweight, pre-term birth, placental complications and perinatal mortality.

About 1 in 7 women who gave birth in 2009 smoked during pregnancy.

The effects of smoking during pregnancy persist into infancy and childhood. Children whose mothers smoked while they were pregnant have been found to be at higher risk of sudden infant death syndrome, childhood cancers, high blood pressure, asthma, lowered cognitive development and other serious problems.

How many women smoke while pregnant? 

Around 1 in 7, or 42,600, women who gave birth in 2009 reported smoking during pregnancy. Teenage mothers were more likely to smoke during pregnancy (37%), with the proportion dropping to around 10% among mothers aged 30 and over. Babies whose mothers smoked during pregnancy were twice as likely to be of low birthweight compared with those who did not smoke (11% and 5% respectively).

What about other drugs? 

According to the 2010 National Drug Strategy Household Survey, women reduced their use of tobacco or illicit substances when pregnant. Of women who were pregnant in the year before the survey, 12% smoked while pregnant, 2% used marijuana and 3% used another illicit substance, down from 16%, 7% and 9%, respectively, when they were not pregnant.

Do rates vary across population groups? 

In 2009, almost half of Indigenous mothers (48%) smoked during pregnancy—3.6 times the rate of non-Indigenous mothers (13%).

Australian-born mothers were almost 3 times as likely to smoke in pregnancy as mothers born overseas (17% and 6% respectively).

Mothers in the most socioeconomically disadvantaged areas were more than 4 times as likely to have smoked in pregnancy as those in the areas of least disadvantage (23% and 5%, respectively).

Low birthweight infants by smoking status of mother in pregnancy, 2009

 

Notes
1. Data for 2009 are not final. Provisional data were provided by Victoria for 2009.
2. Mother’s tobacco smoking status during pregnancy is self-reported.

Source: AIHW National Perinatal Data Collection.

Alcohol use in pregnancy

Maternal alcohol use during pregnancy is associated with severe adverse perinatal outcomes, such as fetal alcohol syndrome and alcohol-related birth defects and developmental disorders.

About half (51%) of women drank alcohol while pregnant in 2010.

Exposure to alcohol in the uterus is the most common preventable cause of birth defects and the leading cause of mental retardation among children. Although the risk of birth defects is greatest with high, frequent maternal alcohol intake during the first trimester, alcohol exposure throughout pregnancy, including before pregnancy is confirmed, can have consequences for fetal brain development.

How many women drink alcohol while pregnant? 

According to the 2010 National Drug Strategy Household Survey, of the estimated 395,000 women who were pregnant in the year before the survey, half (51%) reported drinking alcohol during pregnancy, although most (95%) drank less than before they were pregnant. The proportion of women who drank while pregnant has been decreasing since 2001, when consumption was at 64%.

How many women abstain from drinking alcohol while breastfeeding? 

An estimated 34% of women who were breastfeeding did not drink alcohol. A further 62% drank less than they did before they were pregnant or breastfeeding.

Change in alcohol consumption when pregnant in last 12 months, women aged 14–49, 2001–2010

 

Source: 2010 National Drug Strategy Household Survey, unpublished data.

Birthweight

Babies who are born with low birthweight are at greater risk of poor health, disability and death than other babies.

1 in 16 (6.2%) liveborn babies weighed less than 2,500 grams at birth in 2009.

Birthweight affects a baby’s chance of survival and good health. A birthweight below 2,500 grams is considered low and is a known risk factor for neurological and physical disabilities, with the risk of adverse outcomes increasing with decreasing birthweight.

How many babies are of low birthweight? 

About 18,000, or 6.2%, of babies born in 2009 weighed less than 2,500 grams, including the 1% who weighed less than 1,500 grams. Baby boys were slightly less likely to be of low birthweight than baby girls. The proportion of low birthweight babies has remained steady over the decade to 2009.

Do rates of low birthweight vary across population groups? 

Babies born to younger and older mothers (mothers aged under 20 or 40 and over) were more likely to be of low birthweight (8.6% and 7.6% respectively). Babies of Indigenous mothers were twice as likely as those born to non-Indigenous mothers to be of low birthweight (12% and 5.9% respectively). Babies born to mothers living in the most socioeconomically disadvantaged areas were 1.3 times as likely to be of low birthweight as babies born to mothers living in the areas of least disadvantage.

Low birthweight liveborn babies by maternal age, 2009

 

Note: Data for 2009 are not final. Provisional data were provided by Victoria for 2009.

Source: AIHW National Perinatal Data Collection.

Overweight and obesity

Children who are overweight or obese are at risk of serious health conditions, such as asthma, cardiovascular conditions and Type 2 diabetes.

Over 1 in 5 (23%) children aged 5–14 were overweight or obese in 2007–08.

In addition to their physical health problems, overweight and obese children are frequently victimised and teased by their peers, which can contribute to poor peer relationships and psychological wellbeing. Children who continue to be overweight or obese into adulthood are at greater risk of coronary heart disease, some cancers, and a number of other health disorders.

How many children are overweight or obese? 

According to the 2007–08 ABS National Health Survey, an estimated 430,000 children aged 5–14 were overweight (17%) or obese (6%). There is no clear trend for the prevalence of overweight and obesity with further research needed in this area to clarify trends using different measures.

Does children’s weight vary across population groups? 

Children from socially or economically or geographically disadvantaged backgrounds are more likely to be affected by overweight and obesity than other children. Those living in the most socioeconomically disadvantaged areas were 1.7 times as likely to be overweight or obese (31%) as those living in the least disadvantaged areas (18%) in 2007-08.

Overweight or obese children aged 5–14, by selected population groups, 2007–08

 

(a) Other areas include Inner regional, Outer regional and Remote areas. Very remote areas were excluded from the survey.

Note: Refer to A picture of Australia’s Children 2012, Appendix B: Methods for explanation of remoteness areas, socioeconomic status (SES) and confidence intervals.

Source: ABS 2007–08 National Health Survey, published in AIHW 2011 Headline indicators for children's health, development and wellbeing

Environmental tobacco smoking in the home

Exposure to tobacco smoke puts children at risk of serious health problems, including asthma, respiratory tract infections and sudden infant death syndrome.

In 6% of Australian households with children, someone regularly smoked inside in 2010.

Tobacco smoke contains numerous toxic and cancer-causing chemicals that increase the risk of adverse health outcomes for children. There is no safe level of exposure, and children with parents who smoke are more likely to take up smoking later in life.

How many children are exposed to tobacco smoke at home? 

In 2010, it was estimated that 6% of households with children aged 0–14 had someone who smoked at least one cigarette, cigar or pipe daily inside the home. Smoking in the home has decreased steadily since 1995 when 31% of households with children had someone who smoked regularly inside the home.

Does exposure vary across population groups? 

In 2008, Indigenous children were 3 times as likely to be exposed to tobacco smoke in the home as non-Indigenous children (22% and 7% respectively) based on the 2008 National Aboriginal and Torres Strait Islander Social Survey and the 2007-08 National Health Survey. Exposure to tobacco smoke in the home was highest in households with children in Remote and very remote areas (10%) and lowest in households in Major cities (5%). Children living in the most socioeconomically disadvantaged areas were 4 times as likely as those in the least disadvantaged areas to be exposed to tobacco smoke in the home (12% compared with 3%).

What is being done to protect children?

In 2011, all Australian states and territories had legislation prohibiting smoking in enclosed public places and most outdoor eating and drinking areas. All, with the exception of the Northern Territory, have also introduced legislation to prohibit smoking in private cars when children are present.

Smoking status of households with children aged 0–14, 1995–2010

 

Notes
1. Household smoking status as reported by respondents aged 14 and over. This may include a small number of 14 year olds who smoked inside the home.
2. Smoking status is defined as smoking at least one cigarette, cigar or pipe of tobacco per day in the previous 12 months.

Source: 2010 National Drug Strategy Household Survey, unpublished data.

Tobacco use

Tobacco smoking is the leading cause of preventable deaths in Australia and around the world. People who begin smoking at a young age are more likely to continue smoking into adulthood.

About 1 in 25 (3.8%) students aged 12–14 were smokers in 2008.

Tobacco use causes damage to nearly every organ in the body, and results in considerable ill health. In the long term, it is a major risk factor for a number of serious health conditions including coronary heart disease, chronic obstructive pulmonary disease, stroke, peripheral vascular disease, numerous cancers, and a number of other diseases and conditions. Most smokers take up the habit in adolescence and those who begin smoking when they are 12 or 13 smoke more cigarettes per day than those who begin smoking when they are older.

How many students smoke? 

About 1 in 25 (3.8%) students aged 12–14 were smokers, according to the 2008 Australian Secondary School Students’ Alcohol and Drugs Survey. The rates increase as children get older, with 6.9% of 14 year olds current smokers. There has been a 76% decrease in the proportion of students aged 12–14 who were current smokers since 1984.

How do students get their cigarettes?

In Australia it is illegal to sell cigarettes to persons under 18. The majority of young smokers obtain cigarettes through their friends (48%) or ask someone else to buy them (17%). In 2008, 12% of 12–15 year olds reported buying their last cigarette themselves, down from 17% in 2005).

Do smoking rates vary across population groups? 

While the proportion of Indigenous students aged 12–15 who were current smokers in 2008 was higher than non-Indigenous students (12% compared with 5%), this has declined from 17% in 2005. Students aged 12–14 from the most socioeconomically disadvantaged areas were more likely to be smokers than those from the least socioeconomically disadvantaged areas (5% compared with 3%).

Students aged 12–14 who were current smokers, 1984–2008

 

Source: Australian Secondary School Students’ Alcohol and Drug Survey, various years, Centre for Behavioural Research in Cancer, Cancer Council Victoria, unpublished data.

Alcohol misuse

Alcohol use at a young age is associated with more frequent use during late adolescence and an increased risk of later dependence.

About 1 in 50 (2.2%) of 12–14 year old students in 2008 had drunk more than four standard drinks on a single occasion in the previous week.

Heavy drinking can have significant and detrimental effects on brain development during the early years. Children and adolescents who drink are also at greater risk of suffering accidental injury, experiencing poor mental health or having social problems. Intoxication during early experiences with alcohol has also been associated with an increased risk of problem drinking in adulthood.

How many students engage in risky drinking? 

According to the 2008 Australian Secondary Students Alcohol and Drug Survey, 13% of students had one or more drinks on a single occasion in the previous week. The rate has almost halved since 2002 when 24% of young students reported drinking in the previous week. The proportion who drank more than four drinks on a single occasion has also dropped, from 3.7% in 2002 to 2.2% in 2008.

Does alcohol misuse vary across population groups? 

In 2008, it was estimated that 23% of Indigenous students aged 12–15 had drunk alcohol in the previous week compared with 17% of students overall. The proportion of Indigenous students who had never had a drink was higher than students overall (27% compared with 22%).

The proportion of students who reported drinking more than four drinks on one occasion in the previous week did not seem to vary across socioeconomic groups.

How many students use illicit and over-the-counter drugs? 

Most 12–15 year old students (89%) had not used an illicit substance (cannabis, hallucinogens, amphetamines, cocaine, opiates or ecstasy) or an over-the-counter drug for non-medical purposes in their lifetime. For the 11% who had used a drug, most (20%) used an inhalant (such as sniffing spray cans or glue), and 16% used a tranquiliser.

Trends in students aged 12–14 engaging in risky drinking in the week before the survey, 1990–2008, based on 2001 and 2009 NHMRC guidelines

Notes
1. According to the 2001 guidelines, risky drinking was defined as seven+ standard drinks for males and five+ standard drinks for females on one occasion.
2. According to the 2009 guidelines, risky drinking for adults was defined as more than four standard drinks on one occasion.

Source: Australian Secondary Students’ Alcohol and Drug Survey, various years, Centre for Behavioural Research in Cancer, Cancer Council Victoria, unpublished data.