Alcohol

From: Exposure to Psychotropic Medications and Other Substances during Pregnancy and Lactation: A Handbook for Health Care Providers

On this page:

Summary and recommendations
Fetal effects
Neonatal effects
Long-term effects on the child
Breastfeeding
Withdrawal effects on the mother

Although a legal and socially accepted drug, alcohol poses a health risk to the developing fetus when consumed during pregnancy. Alcohol crosses the placenta and can reach the fetus at levels similar to those in the mother. Since alcohol is the most widely used human teratogen among women of reproductive age, alcohol consumption during pregnancy is the leading preventable cause of neurodevelopmental deficits in Canada. A safe threshold for prenatal alcohol exposure has never been determined.¹

Summary and recommendations

The more alcohol consumed, the higher the risks of major malformations, spontaneous abortion and other effects. Consequently, heavy drinking (often defined as more than two standard drinks per day) and/or binge drinking (when a person consumes five or more standard drinks on one occasion) is considered most harmful.²
Discontinuing alcohol consumption at any time during pregnancy can improve the health outcome for the fetus.³
Good nutrition throughout pregnancy is recommended, which includes taking a prenatal multivitamin once per day during pregnancy.
Breastfeeding women should plan ahead and pump their milk for later use before occasions when they expect to consume alcohol (e.g., social events).⁴ (See Figure 4 [PDF])

Fetal effects

Major malformations

Consuming alcohol while pregnant increases the risk of harm to the baby, including stillbirths, growth restrictions and facial, skeletal, kidney and cardiac defects.⁵^,6

Spontaneous abortion

One study⁷ reports that in over 5,000 pregnant women who consumed alcohol moderately (defined in the study as 3.5 drinks per week) the risk of first trimester spontaneous abortion increased significantly.

Neonatal effects

Newborns can experience withdrawal symptoms of varying severity when the mother is intoxicated during delivery. Common examples include tremors and ventricular tachycardia (a potentially fatal disruption of normal heartbeat). Some newborns will experience severe withdrawal symptoms, such as seizures. In one study, acute withdrawal symptoms were detected in 24 per cent of newborns whose mothers had consumed alcohol close to delivery.⁷

Long-term effects on the child

Fetal alcohol spectrum disorder

Fetal alcohol spectrum disorder (FASD) is an umbrella term that describes the range of physical and neurological effects that can occur in people exposed to alcohol during pregnancy. This disorder is found in approximately one per cent of all births and manifests as brain damage, usually in the absence of obvious physical signs.⁷ The neurological effects may be in the form of abnormal cognition or social behaviour. Symptoms of FASD may have lifelong implications for an individual.⁷

Fetal alcohol syndrome

Fetal alcohol syndrome (FAS) is the most severe and clinically recognizable form of alcohol damage caused in utero. The syndrome’s characteristics include a pattern of distinct facial features, prenatal and postnatal growth retardation, and functional or structural central nervous system abnormalities. FAS is caused by heavy drinking throughout pregnancy, and it is estimated that 4.3 per cent of pregnant women who drink heavily will have babies with FAS.⁸ Several sources state that chronic maternal ingestion of at least 2g/kg/day of alcohol (i.e., about eight standard drinks per occasion) is associated with FAS.⁹

FAS is most easily diagnosed between the ages of eight months and eight years.¹⁰^,3 Early diagnosis and treatment (i.e., prior to six years of age) has been found to considerably improve the long-term outcome for these children.

Breastfeeding

Alcohol enters the mother’s breast milk at levels similar to maternal blood levels, yet the elimination rate from the baby’s body occurs at half the rate of an adult’s. There are potential risks for a baby who receives alcohol. With excessive amounts of alcohol, these risks include possible impairment of the baby’s motor development, changes in his or her sleep patterns and the baby’s refusal to nurse due to a change in the milk’s flavour. High doses of alcohol can also reduce the mother’s rate of milk production.⁴

Figure 4 [PDF] shows an algorithm, created by Motherisk, to calculate how long it will take for alcohol to be eliminated from a woman’s breast milk.

Withdrawal effects on the mother

Withdrawal symptoms typically begin six to 12 hours after the person’s last drink and peak in 24 to 72 hours.¹¹ The most reliable sign of withdrawal is tremor, which is most pronounced when the person reaches for an object. Anxiety, sweating, nausea, vomiting and headache are other common withdrawal symptoms. Many people do not recognize that they are in withdrawal and may attribute their tremors to anxiety.

The risk of withdrawal increases when a person consumes more than 40 drinks per week.¹¹ People who drink heavily and who consume alcohol at a predictable time every day should be carefully assessed for withdrawal symptoms: there is evidence that people who are alcohol dependent may experience subacute withdrawal,¹² which is characterized by insomnia, anxiety, fatigue and alcohol cravings, and may last for months.

Alcohol withdrawal can trigger grand mal seizures (sudden loss of consciousness together with convulsions); other complications include arrhythmia, hallucinations and delirium tremens (a dangerous syndrome consisting of hallucinations, extreme confusion, fever and tachycardia). (Note: Delirium tremens is rarely seen in younger, otherwise healthy patients.)

References

Koren, G., Caprara, D., Chan, D., Jacobson, S. & Porter, K. (2004). Motherisk update: Is it all right to drink a little during pregnancy? Canadian Family Physician, 50, 1643–1644.
Martinez-Frias, M.L., Bermejo, E., Rodriguez-Pinilla, E. & Frias, J.L. (2004). Risk for congenital anomalies associated with different sporadic and daily doses of alcohol consumption during pregnancy: A case-control study. Birth Defects Research. Part A, Clinical and Molecular Teratology, 70 (4), 194–200.
Streissguth, A.P., Bookstein, F.L., Barr, H.M., Sampson, P.D., O’Malley, K. & Young, J.K. (2004). Risk factors for adverse life outcomes in fetal alcohol syndrome and fetal alcohol effects. Journal of Developmental and Behavioral Pediatrics, 25 (4), 228–238.
Koren, G. (2002). Drinking alcohol while breastfeeding: Will it harm my baby? Canadian Family Physician, 48 (1), 39–41. Available: www.cfpc.ca/cfp/2002/jan/vol48-jan-clinical-1.asp. Accessed July 12, 2007.
Sampson, P.D., Bookstein, F.L., Barr, H.M. & Streissguth, A.P. (1994). Prenatal alcohol exposure, birthweight, and measures of child size from birth to age 14 years. American Journal of Public Health, 84 (9), 1421–1428.
Chudley, A.E., Conry, J., Cook, J.L., Loock, C., Rosales, T. & LeBlanc, N. (2005). Fetal alcohol spectrum disorder: Canadian guidelines for diagnosis. Canadian Medical Association Journal, 172 (5 Suppl.), S1–S21.
Windham, G.C., Von Behren, J., Fenster, L., Schaefer, C. & Swan, S.H. (1997). Moderate maternal alcohol consumption and risk of spontaneous abortion. Epidemiology, 8 (5), 509–514.
Abel, E.L. (1995). An update on incidence of FAS: FAS is not an equal opportunity birth defect. Neurotoxicology and Teratology, 17 (4), 437–443.
Koren, G. (1994). Maternal-Fetal Toxicology: A Clinician’s Guide (2nd ed.). New York: Marcel Dekker.
Romera Modamio, G., Fernández López, A., Jordán García, Y., Pastor Gómez, A., Rodriguez Miguélez, J.M., Botet Mussons, F. et al. (1997). Alcoholic embryofetopathy: Neonatal case reports for the past twelve years. Anales Españoles de Pediatria, 47 (4), 405–409.
Kahan, M. & Wilson, L. (2002). Managing Alcohol, Tobacco and Other Drug Problems: A Pocket Guide for Physicians and Nurses. Toronto: Centre for Addiction and Mental Health.
Hornyak, M., Haas, P., Veit, J., Gann, H. & Riemann, D. (2004). Magnesium treatment of primary alcohol-dependent patients during subacute withdrawal: An open pilot study with polysomnography. Alcoholism: Clinical and Experimental Research, 28 (11), 1702–1709.