Full Text Review
Please note: In 2003, the CTF updated its Grades of
Recommendations to include an "I Recommendation" for situations where
insufficient evidence exists to allow a recommendation to be made.
(Formerly, these situations were captured under a "C
Recommendation".) This change is not retroactive, and all
"C Recommendations" made prior to 2003 have not been
reevaluated in light of the new "I" recommendation grade. For a
discussion of these recommendation grades, please link to the 2003 article in
the Canadian Medical Association Journal here.
Primary Prevention of Fetal Alcohol Syndrome
Prepared by David R. Offord, MD, FRCPC, Department of Psychiatry,
McMaster University, and Deborah L. Craig, MPH, Health Care Consultant,
Halifax, Nova Scotia
These recommendations were finalized by the Task Force in March 1994
Contents
Overview
In 1979
the Canadian Task Force on the Periodic Health Examination found there
was fair justification for recommending that counselling to reduce alcohol
intake in pregnant women should be included in the periodic health examination
(B recommendation).< 1,2>
This was based on evidence that counselling was effective in reducing both
the amount of drinking in pregnant women and morbidity in their offspring.
The evidence since 1979
supports the original recommendation. Also considered was contraception
for alcoholic sexually active women, and, if acceptable, the offer of abortion
for pregnant women at high risk.
More general concerns regarding problem drinking
have been dealt with in Chapter 42 and are beyond the scope of this report.
In brief, however, in 1989<3>
and again in this update the Task Force found there was fair evidence that
case-finding, counselling and follow-up are effective in managing problem
drinking. This volume also contains a separate report on the psychological
consequences to children of having alcoholic parents (Chapter 41).
Burden
of Suffering
Fetal Alcohol Syndrome (FAS) refers to a constellation
of congenital and functional anomalies occurring in children born to alcohol-abusing
women. First documented in 1973
by Jones and Smith,<4> FAS has become one of the most actively researched
congenital abnormalities in the last two decades.<5> Criteria for defining
FAS were standardized by the Fetal Alcohol Study Group<6> and modifications
were proposed in 1989
by Sokol and Clarren.<7> FAS is now one of the leading causes of mental
retardation. It has been estimated that 50% of FAS victims are mentally
retarded and another 30% suffer borderline mental retardation.<8> It
is generally accepted that the harmful effects of prenatal alcohol exposure
can be plotted on a continuum, with spontaneous abortion at one end, FAS
in the middle and subtle behavioral abnormalities at the other end of the
scale. FAS represents the severest disabilities caused by maternal alcohol
use during pregnancy. The term "possible fetal alcohol effects" (FAE) has
been introduced to indicate that alcohol is being considered as one of
the possible causes of a patient’s birth defects, but there are not sufficient
features for a firm diagnosis of FAS or strong evidence of an alternative
diagnosis.<7>
The accurate determination of the incidence of FAS
is difficult primarily because the syndrome is not reliably recognized.
It has been reported that between 8% and 11%
of child-bearing women in the United States are either problem drinkers
or alcoholics. Further, it has been reported that 65% of fetuses are exposed
to alcohol prenatally throughout the United States. Between 3% and 10%
of pregnant women report patterns of alcohol consumption that have corresponded
with harming the fetus.<9> This figure may be low as it is generally
accepted that self-reporting of alcohol consumption in women is under-reported
due to denial. The precise incidence and prevalence of FAS and FAE are
not known in Canada. It is estimated that the incidence rate of FAS is
between 1 and
2 per 1,000
live births in the general population. Based on these data, between 400
to 500 Canadian children are born annually with FAS. The incidence of FAS
is markedly increased in the native population and in poor, inner-city
neighbourhoods, as well as rural, remote villages. The highest reported
prevalence of FAS is one child in eight in a native community in British
Columbia where all mothers and their offspring were systematically evaluated.<10>
Experts agree that the actual amount of alcohol needed
to produce FAS and the precise risk of embryo-fetal damage is largely unknown.
It is widely accepted that there is a dose-response relationship, but it
is not known how large a dose is needed to cause an injurious effect to
the fetus. Investigators<11,12>
report that the teratogenicity of alcohol is strictly dose dependent with
direct dose-response effects on infant weight, perinatal mortality and
soft-tissue malformations.
Lastly, it is known that not all alcoholic women
are at risk for giving birth to an alcohol-affected child; genetic and
physiologic factors may mediate the risk.<13>
Ethnic and cultural factors, family history and tobacco and multiple drug
use have been identified as variables that may mediate the risk of morbidity
in the offspring of alcoholic mothers.
Maneuver
It is known that, unlike other congenital birth defects,
alcohol-related birth defects are preventable. Experts agree that the development
of effective screening methodologies to identify women at high risk for
heavy alcohol consumption is the key strategy to preventing alcohol-related
birth defects. Determining the need for education, counselling and treatment
for these patients is dependent on recognition of the patient’s problem.
Identifying high-risk drinkers is difficult for physicians, however. Laboratory
tests which might identify biochemical markers of heavy drinking are not
available<14>
and obtaining an accurate history of maternal alcohol consumption can be
complicated by psychological denial.
A number of screening tests for the estimation of
alcohol consumption are available. The Michigan Alcoholism Screening Test
(MAST) is a 25-question instrument which is extensively utilized for research
but is time consuming and thus clinically impractical.<15>
The CAGE test is a more recent and effective screening test; it is only
four questions long, but has not been studied in pregnancy.<16>
Recently, a screening test for the early detection of hazardous and harmful
alcohol consumption for use in primary care settings has been developed
by the World Health Organization.<17>
Again, it has not been specifically tested on pregnant populations.
In 1988,
Cyr and Wartman<18>
proposed two questions that would improve the practitioner’s chances of
identifying the alcoholic patient. The questions, "Have you ever had a
drinking problem?" combined with "When was your last drink?" had a sensitivity
of 91.5%.
The researchers recommend the routine incorporation of these two questions
into the medical history of the outpatient population to aid in the initial
diagnosis of alcoholism.
Sokol and colleagues<19>
developed a four-question survey tool to help eliminate denial and under-reporting
of heavy drinking by pregnant women. Referred to as the T-ACE, the questionnaire
accurately identified 69% of the risk drinkers from a cohort of 971
pregnant
women. T-ACE was determined to be superior to other standard questionnaires
such as MAST and CAGE for detecting heavy alcohol abuse. Another instrument,
a brief Ten Question Drinking History (TQDH) has been incorporated into
the Boston City Hospital prenatal clinic record.<20> Reliability has
been demonstrated, and the data obtained by obstetrical staff using the
TQDH were comparable to those obtained in a more elaborate research interview.
It remains a diagnostic challenge to gain an accurate
drinking history from many patients. Laboratory results may prove to be
entirely normal though risk-drinking exists. Obtaining a thorough and sensitive
history from a possibly evasive and denying patient remains the best technique
for identifying risk-drinking.<21>
Two points should be kept in mind about screening pregnant women for alcohol
intake. It is likely that if the patient screens positive, the response
is accurate. However, a negative result on the screen is not necessarily
accurate. Second, if the goal is to eliminate all maternal drinking during
pregnancy, then the screen simply has to identify any vs. no alcohol intake
rather than varying levels of alcohol use.
In the absence of a clearly defined safe threshold
for alcohol consumption during pregnancy, experts widely agree that the
most conservative approach is best. Therefore, most clinicians advise total
abstinence for women who are either considering pregnancy or who are pregnant.
This widely accepted recommendation has not gone unchallenged, however.
Knupfer<22> has argued that there is no evidence that light drinking
is harmful to the fetus and that defects exist in the literature regarding
methodologies for categorizing drinking patterns and drawing conclusions
from them.
Effectiveness
of Prevention
As it is widely accepted that there is no effective
treatment for offspring with FAS and FAE, the challenge to physicians and
other health care providers lies in the prevention of FAS and FAE through
early identification of women who are abusing alcohol and the implementation
of treatment interventions with the mother.
Patient Intervention
Several studies have noted the positive benefits of
interventions during pregnancy with alcohol-abusing women. Coles and coworkers<23>
found that infants of mothers who stopped consuming alcohol in the second
trimester displayed less growth retardation and fewer neurobehavioural
deficits than neonates of women who continued to drink at the same rate
throughout the pregnancy. Other researchers have noted that the risk for
intrauterine growth retardation and central nervous system effects decrease
in the newborns of mothers who lessen or discontinue their alcohol use
during pregnancy.
In one study, alcohol counselling was provided to
85 pregnant women to persuade them to reduce or eliminate their alcohol
consumption. Sixty-five percent of the women were able to decrease their
alcohol intake by at least 50%. In the total sample, 24% of the offspring
had complete FAS, while 26% displayed FAE. Of the women with continuous
alcohol consumption, 89% gave birth to neonates with at least one FAE feature
compared with only 40% of women who reduced their alcohol intake.<24>
There is evidence that therapeutic interventions
in the prenatal clinic setting can be effective in promoting a decrease
in alcohol intake, even in high-risk heavy drinkers. Rosett and Weiner<25>
reported that 67% of a group of heavy drinkers either decreased or abstained
from alcohol use following an intervention of supportive counselling. Larsson<26>
reported similar results in that 76% of the women either decreased or eliminated
drinking following a minimal intervention which consisted mainly of the
provision to the mothers of information about the effects of alcohol consumption
during pregnancy. The results of these studies suggest that alcohol-abusing
women are responsive to intervention during pregnancy, possibly more so
than at any other time.
Professional
Education
The literature substantiates a lack of awareness among
health care providers regarding the range of symptoms associated with FAS
and FAE. Many clinicians do not comprehend the ramifications correlated
with these diagnoses for the child’s development. The diagnosis of alcoholism
is often missed as well. Sokol and colleagues<27> have found that clinicians
are failing to diagnose alcoholism in at least three of four alcohol-abusing
patients. The researchers believe that no other diagnosis is missed as
frequently. There are many reasons why doctors do not routinely ask about
alcohol consumption among their pregnant patients. Such explanations include
physician bias regarding their own abuse, inadequate training for the task,
poor awareness of the problem and its consequences, time restrictions,
disinterest, fear of offending the patient, disbelief and denial that FAS
occurs in private practice and the view that patients will deny their alcohol
use.
Role of the Physician
Several authors stress the importance of the doctor-patient
interaction as key in the prevention of alcohol-related birth defects.
As many communities have limited resources available to women of child-bearing
age, the role of the clinician providing perinatal care becomes even more
critical.
Public Prevention
Strategies
There are few empirical studies regarding the impact
of warning labels on alcohol beverage containers. This is not surprising
as Canada does not have legislation requiring warning labels and the U.S.
only recently enacted the warning label law in November 1989.
However, there is evidence that warning labels can influence behaviour
based on studies regarding tobacco, foods and illegal drugs. Further, evidence
exists supporting the idea that public educational efforts are effective
in modifying behaviour, especially among social drinkers.
Recommendations
of Others
The Canadian Medical Association strongly supports all
activities that encourage Canadians to reduce their alcohol intake. The
Association recommends that the Federal Government prohibit all advertising
of alcoholic beverages on radio and television, as well as in printed materials.
A Health and Welfare Sub-Committee has recommended to the Minister that
the Food and Drug Act be amended to require that alcohol beverage containers
sold in Canada carry appropriate warning labels alerting consumers that
alcohol consumption during pregnancy places the fetus at risk of FAS and
FAE. Lastly, the recommendations of American medical organizations are
in agreement with those of the Canadian medical community, in that total
avoidance of alcohol consumption during pregnancy is the safest course
of action. Abstinence of maternal drinking is the official recommendation
of the U.S. Surgeon General, the American College of Obstetricians and
Gynecologists, the American Council of Science and Health, as well as the
American Medical Association Council on Scientific Affairs. In 1989,
the U.S. Preventive Services Task Force recommended that all persons who
use alcohol, especially pregnant women, should be encouraged to limit their
consumption.<28>
Conclusions
and Recommendations
The child born to an alcoholic mother is at risk for
the development of craniofacial anomalies, mental retardation and a wide
spectrum of developmental delays. There is evidence that counselling is
an effective intervention in decreasing both the amount of drinking in
pregnant women and morbidity in their offspring.
There is fair justification to support the recommendation
that screening and counselling be included in a routine health examination
of pregnant women (B
Recommendation).
Unanswered
Questions (Research Agenda)
The following have been identified as research priorities:
-
Determining the incidence of FAS and FAE in Canada,
among the Canadian population in general, as well as in subpopulations
known or suspected to be at higher risk for these disorders.
-
Improving the ability of clinicians to identify accurately
the drinking patterns of pregnant women.
-
Improving knowledge about fetal and maternal susceptibility
to alcohol, time of exposure during pregnancy, effects of varying quantity
and concentration of alcohol, patterns of drinking, as well as other dose-response
relationships which further define the embryonic and fetal risk.
-
Evaluating promising treatment programs for alcoholic
women.
-
Increasing public awareness of the effects on the offspring
of maternal alcohol consumption during pregnancy.
-
Determining the effectiveness in high-risk populations
(eg., Natives) of counselling to reduce the consumption of alcohol in pregnant
women.
Evidence
The literature in this review was identified during
a MEDLINE search from 1988
to February 1993,
using the following MESH heading: fetal alcohol syndrome. This review was
initiated in January 1993
and recommendations were finalized by the Task Force in March 1994.
Acknowledgements
Funding for this report was provided by Health Canada
under the Government of Canada’s Brighter Futures Initiative. The Task
Force thanks Tim Oberlander, MD, FRCPC, Developmental Pediatrician, Assistant
Professor of Pediatrics, University of British Columbia, Vancouver, BC;
and Sarah Shea, MD, FRCPC, Assistant Professor of Pediatrics, Dalhousie
University, Halifax, NS for reviewing the draft chapter.
Full Citation
Link to Structured Abstract of
this review
Link to Summary Table of this
review
Link to Selected References list of this review
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