Screening for alcohol use in pregnancy
Key messages about alcohol use during pregnancy
Primary care providers should convey these important messages to women who are pregnant or planning pregnancy:
- Alcohol is a well-documented teratogen and evidence shows that alcohol consumption during pregnancy can lead to negative outcomes.
- There is no safe threshold for alcohol use during pregnancy, and no safe time to drink during pregnancy.
- The best advice: no alcohol use during pregnancy and breastfeeding.
Effects of low to moderate alcohol use during pregnancy
Low to moderate levels of alcohol consumption in pregnancy are defined as up to two standard drinks per day (Carson et al., 2010).
Low to moderate alcohol use during pregnancy:
- is associated with an increased risk of spontaneous abortion and an inconsistent effect on stillbirth rates (Andersen et al., 2014; Henderson et al., 2007; Makarechian et al., 1998)
- is associated with adverse long-term outcomes, including poorer behavioural development, such as increased impulsivity, aggression and social problems, as well as behaviour regulation problems (Flak et al., 2014; Swedish National Institute of Public Health, 2009; Testa et al., 2003)
- may be associated with poorer cognitive development – no consistent findings relating to cognition, language skills and visual or motor development (Flak et al., 2014)
- is not associated with fetal malformations, premature birth or impaired growth (Henderson et al., 2007; Makarechian, 1998; Polygenis et al., 1998).
Reassure women who engaged in low-level alcohol use early in pregnancy (i.e., before learning they were pregnant) that there is insufficient evidence to consider terminating the pregnancy.
Risks of heavy or binge drinking during pregnancy
Heavy drinking during pregnancy is defined as more than two standard drinks a day. Binge drinking is defined as four or more drinks per drinking occasion.
Poor cognitive and developmental outcomes have consistently been demonstrated with heavy and binge drinking during pregnancy (Flak et al., 2014).
This level of drinking during pregnancy is associated with a higher prevalence of fetal alcohol spectrum disorder (Chudley et al., 2005). However, more recent findings show that even lower levels of alcohol use can lead to negative pregnancy outcomes.
Fetal alcohol spectrum disorder (FASD)
FASD is not a clinical diagnostic term. It is an umbrella term for a range of physical, mental and behavioural effects and learning disabilities. It includes fetal alcohol syndrome (FAS) and alcohol-related effects.
FASD occurs in about one in 100 live births. It is diagnosed in 30 to 40 per cent of children whose mothers drank heavily while pregnant.
FASD causes primary disabilities (e.g., specific deficits in language, poor impulse control, problems in attention or judgment), which can result in secondary disabilities (e.g., mental health and legal problems).
Fetal alcohol syndrome (FAS)
FAS is a diagnosis based on a characteristic pattern of facial anomalies, growth restriction and central nervous system developmental abnormalities.
It occurs in one to three in 1,000 live births, and is diagnosed in four to five per cent of children whose mothers drank heavily during pregnancy.
Alcohol-related birth defects (ARBD) include cardiac, skeletal, renal, ocular, auditory and other malformations.
Alcohol-related neurodevelopmental deficits (ARND) include:
- neurodevelopmental abnormalities (e.g., structural brain abnormalities
- neurological signs such as impaired fine motor skills or poor eye-hand co-ordination)
- behavioural or cognitive abnormalities (e.g., learning difficulties, poor impulse control, problems with memory, attention or judgment).
Candidates for alcohol screening during pregnancy
Alcohol use during pregnancy is common. In national population surveys, up to 11 per cent of women reported drinking at some point during their pregnancy.
Most women reported drinking infrequently. Less than one per cent reported having more than two drinks on days when they drank (Public Health Agency of Canada, 2005, 2009).
All women of childbearing age should be screened regularly for alcohol use, from preconception, throughout pregnancy and during the postpartum period.
Screening techniques and tools
Screening for alcohol use is intended to differentiate between women who drank alcohol before being aware of their pregnancy and women with an alcohol use disorder (Carson et al., 2010).
Direct questions about quantity and frequency of alcohol intake may elicit positive responses. However, anticipate that pregnant women may deny or under-report alcohol use for various reasons.
Screening questionnaires may help to detect at-risk drinking during pregnancy (>1 oz of absolute alcohol, equivalent to >2 drinks per day). This level of alcohol exposure affects fetal growth and leads to cognitive deficits (Russell, 1994).
The TWEAK and the T-ACE are two validated screening tools that were developed for pregnant women. The tools have about equal sensitivity (Carson et al., 2010; Russell, 1994; Waterson & Murray-Lyon, 1989).
A positive screen indicates a need for further discussion about prenatal alcohol exposure and assessment for alcohol use disorder.
Risks factors for alcohol use during pregnancy
Certain factors increase the likelihood that a woman will engage in harmful drinking during pregnancy (Carson et al., 2010; Public Health Agency of Canada, 2009). These risk factors include:
- past year drinking, specifically heavy weekly drinking prior to pregnancy (women under age 25 have the highest rates of exceeding low-risk drinking)
- lower education level (i.e., at most, completed high school)
- use of other substances that are commonly misused with alcohol, such as cocaine and tobacco
- lower socioeconomic status
- drinking and other drug use by the woman's partner during her pregnancy
- poor access to prenatal and postnatal care and services
- inadequate nutrition
- stressful environment (e.g., violence, history of abuse).
These demographic and psychosocial factors may also decrease the likelihood that a woman will reduce her alcohol use during pregnancy. They may reduce the success of interventions aimed at achieving abstinence from alcohol (Carson et al., 2010).
The Antenatal Psychosocial Health Assessment (ALPHA) is a useful screening tool for psychosocial risk factors such as alcohol and substance use, domestic violence and depression. The ALPHA includes the CAGE, which may be supplemented by the T-ACE or TWEAK.
Barriers to identifying pregnant women with alcohol use disorder
Various personal, interpersonal, systemic and societal factors may prevent women from disclosing alcohol use during pregnancy (Health Canada, 2001a).
- shame and guilt
- stigma associated with mothers misusing substances.
- fear of losing children to partner or child welfare
- lack of family support.
- lack of appropriate services for pregnant women
- lack of reliable child care.