Although we do not know precisely the mechanisms of action of alcohol on human fertility nor a precise risk threshold, it is now established that there is a cause and effect relationship between alcohol consumption and the design timeframe.

In women, alcohol can impair fertility via different mechanisms: by causing irregular and non-ovulatory cycles, by increasing the risk of miscarriage (2).

In humans, alcohol consumption could be responsible for:

• a decrease in testicular volume
• decreased libido
• decreased sperm production (3). A recent Danish study (4) carried out on 1 men aged 221 to 18 observed a decrease in the quantity but also in the quality of sperm after consuming alcohol a week earlier, from 28 drinks per week. The researchers specify, however, that this effect is reversible: stopping alcohol generally makes it possible to find a satisfactory number of sperm in just a few months.

When the expectant mother consumes an alcoholic drink, the ethanol passes from the maternal blood to the blood of the fetus through the placenta. Quickly, the alcohol concentration of the baby’s blood increases and his blood alcohol level is ultimately identical to that of the mother. With this difference, however: the baby’s liver is immature, so it is unable to metabolize alcohol. Depending on the stage of pregnancy, this presence of alcohol can interfere with the proper development of fetal organs and its growth. We can see:

– neurotoxic effects, because alcohol has a direct impact on brain structures. “It is increasingly demonstrated that prenatal exposure to alcohol, by cellular mechanisms that we do not yet all know, modifies sensitive brain structures and in particular the hippocampus. This can result in cognitive, behavioral and memorization disorders ”, indicates the National Academy of Medicine in its report (5) of 2016. A recent Danish prospective survey (6) reports an overall IQ score (intelligence quotient ) and a lower verbal IQ score in 5-year-olds whose mothers had 9 or more drinks of alcohol per week during pregnancy. Different studies (7) (8) report attention disorders, hyperactivity, and learning disorders more frequent in the event of moderate alcohol consumption during pregnancy.

– a risk of prematurity and hypotrophy in the event of high alcohol consumption. Alcohol would affect the growth and functions of the placenta, which then no longer properly plays its role as a platform for exchanges between the fetus and the mother. A systematic review (9) thus shows that although moderate alcohol consumption is not associated with the risk of prematurity or hypotrophy, high consumption increases these risks.

In its most severe and complete form, prenatal alcohol exposure manifests as Fetal Alcohol Syndrome (FAS). It is the French pediatrician Paul Lemoine who first in 1968, in his study “The children of alcoholic couples” (10), described this syndrome which is characterized by this triad of symptoms:

• a characteristic craniofacial dysmorphia: narrow eye cleft, collapsed root of the nose, elongated philtrum (dimple in the middle of the upper lip), thin and narrow upper lip, small indented chin. This dysmorphia is present from birth; it is irreversible but can change or diminish.
• a growth retardation which is increasing over the years.
• mental retardation with intellectual deficit, which also worsens over the years, have confirmed various studies (11) (12).

In France, Fetal Alcohol Syndrome (FAS) concerns at least 1% of births (1 ° / 00 for severe forms of complete FAS), or about 8000 newborns per year, recalls the National Academy of Medicine.

Alongside the Fetal Alcohol Syndrome (FAS) itself, we can also distinguish:

– Partial or incomplete syndromes: only one or a small number of signs of FAS are present at birth. The intellectual deficit is still present.

– Disorders Caused by Fetal Alcoholisation (FASD), which includes all the disorders resulting from alcohol consumption during pregnancy. That is :

– at birth: maladjustment disorders, breastfeeding and feeding difficulties, sleep disorders.

– at school age: behavioral abnormalities, cognitive disorders, an IQ lowered by 20 points, dyslexia, dyscalculia (difficulty in calculating), attention disorders

– in adolescence: attention deficit with hyperactivity, oppositional attitude with provocation (TOP), intolerance with frustration, aggressiveness, difficulty integrating into school.

– in adulthood: intellectual retardation, behavioral disorders, impulsivity, instability, sleep disorders, emotional disorder, dependence on alcohol and / or drugs.