November 27, 2015
Position Statement from the European Board and College of Obstetrics & Gynaecology (EBCOG)
Alcohol and pregnancy
Dr Hanna Kahila – Associate Professor Erja Halmesmäki
For over 40 years, drinking during pregnancy has been recognized as potentially harmful to the baby. Children exposed to heavy prenatal alcohol consumption may have a number of physical and brain abnormalities as well as restricted growth. Neurodevelopmental damage may lead to serious learning and behavioral problems, while those exposed to lower alcohol consumption may also show mild adverse effects. (1)
Social drinking during pregnancy among western women is common, but there is still no consensus even among professionals, whether drinking small amounts of alcohol during pregnancy harms the baby. However the greater the exposure, the greater the risk to the fetus, although there is probably a threshold above which damage is more likely.(2) It is of concern that the reported amount of alcohol used is not standardised. The size of a drink varies between countries and one serving of an alcoholic beverage may not equal the standard drink originally defined as containing 12 g of absolute alcohol. (3) Nevertheless it has been reported that alcohol consumption of more than one unit per day in pregnancy increases the risks of preterm delivery and birth of a baby smaller than it should be, as well as being associated with an increased risk of miscarriage. (4)
Timing is important in determining the effects of alcohol in pregnancy. During the first three months, the risk of structural anomalies is increased, while later in pregnancy both the growth of the baby and brain development are at risk. The risks increase with the overall consumption during pregnancy, but also depend on the drinking pattern. (5) For example binge drinking leads to high peak values of blood alcohol which, at critical periods of development, may lead to fetal damage. However the definition of binge drinking differs and there is considerable variation among women and fetuses in how they metabolise and cope with alcohol. A case is reported of twins exposed to alcohol, with one clearly affected and the other one less so.
The impact of drinking low-to-moderate levels of alcohol in pregnancy (often defined as 1-6 units per week in healthy non pregnant women) is of concern, although the results remain controversial. (6) Prenatal alcohol exposure at levels less than daily drinking has been associated with detrimental child behaviour, although in other studies low levels of alcohol consumption (1-2 units per week) were not linked to similiar problems.
Other factors will also be important. A subtle decrease in IQ in genetically vulnerable offspring has been noticed even when alcohol exposure has been low. Evidence suggests that younger women with unplanned pregnancies are more likely to drink heavily and in a binge drinking pattern. Also relevant is the fact that under reporting of drinking habits is common, and it appears that most cases of alcohol abuse during pregnancy may not be identified by clinicians.(7)
So based on what is known as well as the continuing uncertainty as to whether any safe consumption threshhold exists, EBCOG supports the consensus which recommends that women should ideally abstain from alcohol during pregnancy or when planning pregnancy (2). That being said it has to be understood that there is limited evidence that drinking small amounts of alcohol in pregnancy causes harm to the baby.
But as important, EBCOG considers it essential that providers of women’s health care, as well as those responsible for health education in schools, should provide information on the consequences of unprotected sex and alcohol use as well as the possible effects of drinking alcohol while pregnant on the next generation. Furthermore there should be a determined effort to identify women with disorders of alcohol use at the earliest stage of pregnancy, and preferably before pregnancy, and refer them to the most appropriate service.
1.Dörrie N, Föcker M, Freunscht I, and Hebebrand J. “Fetal alcohol spectrum disorders” Eur Child Adolesc Psychiatry 2014;23:863–875
2.Patra J, Bakker R, Irving H, Jaddoe VWV, Malini S, Rehm J. Dose-response relationship between alcohol consumption before and during pregnancy and the risks of low birth weight, preterm birth and small-size-for-gestational age (SGA) – A systematic review and meta-analyses. BJOG 2011;118:1411-1421
4.Feodor Nilsson S, Andersen PK, Strandberg-Larsen K, Nybo Andersen A-M. Risk factors for miscarriage from a prevention perspective: a nationwide follow-up study. BJOG 2014;121:1375– 1385.
5.Flak AL, Su Su, Bertrand J, Denny CH, Kesmodel US, Cogswell ME. The Association of Mild, Moderate, and Binge Prenatal Alcohol Exposure and Child Neuropsychological Outcomes: A Meta-Analysis. Alcohol Clin Exp Res 2014;38:214–226.
6.Gray R. Low to moderate alcohol consumption during pregnancy and child development – moving beyond observational studies. BJOG 2013;120:1039-1041.
7.O’Leary CM, Halliday J, Bartu A, D’Antoine H, Bower C. Alcohol-use disorders during and within one year of pregnancy: a population-based cohort study 1985–2006. BJOG 2013;120:744-753
The first draft of this Paper was written by Dr Hanna Kahila and Associate Professor Erja Halmesmäki (both Helsinki University Central Hospital), and peer reviewed by the following: Dr Alex Baldacchino, University of Dundee; Professor Luis Graca, University of Lisbon; Dr Marjetka Hovnik Kersmanc, National Institute of Public Health, Slovenia; Associate Professor Ulrik Schiøler Kesmodel, Aarhus University Hospital; Professor Moira Plant, University of the West of England; Assistant Professor Tim Van Mieghem, University Hospitals Leuven.
The final version was approved by the President and Executive of EBCOG.