addition, damage to the central nervous system and peripheral nervous system (e.g., painful peripheral neuropathy) can occur from chronic alcohol misuse. The developing adolescent brain is particularly vulnerable to the toxic effects of alcohol. A systematic analysis found, that the level of alcohol consumption recommended by many existing guidelines is too high in particular for young people in all regions. DNA damage Acetaldehyde is produced when cells process ethanol. Acetaldehyde, is a DNA damaging metabolite that can interact with DNA to crosslink the two strands of the DNA duplex. The mechanisms the cells use for repairing these crosslinks are error prone, thus leading to mutations that in the long term can cause cancer. Pregnancy Medical organizations strongly discourage drinking alcohol during pregnancy. Alcohol passes easily from the mother's bloodstream through the placenta and into the bloodstream of the fetus, which interferes with brain and organ development. Alcohol can affect the fetus at any stage during pregnancy, but the level of risk depends on the amount and frequency of alcohol consumed. Regular heavy drinking and heavy episodic drinking (also called binge drinking), entailing four or more standard alcoholic drinks (a pint of beer or 50 ml drink of a spirit such as whisky corresponds to about two units of alcohol) on any one occasion, pose the greatest risk for harm, but lesser amounts can cause problems as well. There is no known safe amount or safe time to drink during pregnancy, and the U.S. Centers for Disease Control and Prevention recommends complete abstinence for women who are pregnant, trying to become pregnant, or are sexually active and not using birth control. Prenatal alcohol exposure can lead to fetal alcohol spectrum disorders (FASDs). The most severe form of FASD is fetal alcohol syndrome (FAS). Problems associated with FASD include abnormal facial development, low birth weight, stunted growth, small head size, delayed or uncoordinated motor skills, hearing or vision problems, learning disabilities, behavior problems, and inappropriate social skills compared to same-age peers. Those affected are more likely to have trouble in school, legal problems, participate in high-risk behaviors, and develop substance use disorders like excessive drinking themselves. Cardiovascular disease In 2010, a systematic review reported that moderate consumption of alcohol does not cause harm to people with cardiovascular disease. However, the authors did not encourage people to start drinking alcohol in the hope of any benefit. In a 2018 study on 599,912 drinkers,