During the first few days of pregnancy (before the absence of menstruation), the embryo undergoes rapid changes in its development until it forms a blastocyst. This is the name given to embryos that manage to develop up to day 5-6 of development and form a specific structure. It is at this stage that it should implant in the uterus. When this happens, the gastrulation process begins, in which the cells of the embryo have to differentiate into three layers (endoderm, mesoderm, and ectoderm) and begin to form rudimentary organs.
This period is particularly sensitive to any type of toxicant, including exposure to alcohol. Any aggression could alter this evolutionary process of the embryo and produce problems in the embryo.
Most of the studies carried out on the effect of alcohol in these early stages have been carried out in mice, and have shown that alcohol intake is clearly detrimental. Placental volume and proper functioning of the placenta in exposed mice was found to be much lower than in mice that did not ingest alcohol.
In addition, one study showed that a single dose of alcohol at this stage could cause craniofacial malformations similar to those of fetal alcohol syndrome.
Therefore, total abstinence from all alcoholic beverages is recommended to all pregnant women or women who are trying to become pregnant.