”It is the best of times, it is also the worst of times”, Dickens’s famous quote has become the best footnote of our time: people’s income has increased, life has improved, but the pressure has become unprecedentedly large. In order to relieve stress and soothe the mood, many people have developed the habit of smoking, drinking, drinking coffee, staying up late, not knowing that this brings greater risks, such as damage to health, and then the negative impact on the baby to be born …… bad habits may make you temporarily away from stress, relaxation, but it is likely to make you to go deeper into pain. Putting aside other negative effects, we only from the perspective of eugenics, talk about the following bad habits and the relationship between birth defects in newborns. Smoking More and more scientific data prove that whether the father smokes or the mother smokes, or passive parental smoking, are important factors that cause birth defects in newborns, the more smoking, the higher the incidence of birth defects in newborns. Paternal smoking directly affects the development and quality of sperm. A study of 120 adult men who had smoked for more than one year found that the number of malformed and other poor quality sperm was directly related to the amount of smoking. The harmful substances contained in cigarettes, such as nicotine, can induce sperm malformations and mutations, ultimately leading to the development of birth defects in newborns. The dangers of maternal smoking or passive smoking are equally great. Women who smoke or passive smoking during pregnancy have the following effects on the fetus: (1) high incidence of premature births. According to a survey of 7499 pregnant women, the incidence of preterm infants smoking group is 12.5%, non-smoking group is 6.8%, the difference between the two is huge. (2) Smoking causes uterine contractions, which increases the incidence of miscarriage. (3) The incidence of birth defects in newborns is high. A scientific study shows that the incidence of congenital heart disease in infants smoking group is 0.77%, non-smoking group only 0.47%, a significant difference. The reason for this is that smoking releases nicotine and carbon monoxide, which affects the development of the fertilized egg, leading to the occurrence of fetal malformations. Second, alcohol consumption by parents is harmful to the newborn. The harm of alcohol consumption is mainly caused by ethanol and its intermediate metabolite acetaldehyde, and is related to the amount of alcohol intake, frequency of alcohol consumption and the ability of the body to metabolize and convert alcohol dehydrogenase (break down alcohol) and acetaldehyde dehydrogenase (break down acetaldehyde). Long-term alcohol consumption in men can lead to chronic alcoholism, which affects libido and sperm development and has a high rate of sperm malformation. It is well documented that men with chronic alcoholism give birth to fetuses with developmental delays from childhood, motor and mental disorders, and multiple malformations. Chronic heavy alcohol consumption by pregnant women may lead to fetal alcohol syndrome. Fetal alcohol syndrome is characterized by three aspects: prenatal and postnatal developmental delays; specific facial features after birth; and central nervous system abnormalities. Those that exhibit only some of these features are called fetal alcohol effects. The most significant hazard of fetal alcohol syndrome is the effect on the central nervous system. Prolonged exposure of the fetus to alcohol can hinder the development of nerve cells or brain structures such as the cerebellum, hippocampus, and frontal cortex, or even form malformations, generally leading to a cascade of primary cognitive and functional impairments, including memory weakness, attention deficit, impulsive behavior, and poor comprehension, in addition to secondary disorders such as mental illness and drug addiction. In Western countries, heavy alcohol use by prospective parents has caused serious social problems. Some couples in countries such as the United Kingdom and the United States like to drink and have fun on weekends or holidays. The fetuses conceived after drinking are often stunted and mentally retarded, showing the typical fetal alcohol effect. Due to the large number of such births, which are common, people call this type of baby “Sunday babies”. “Sunday babies” bring endless suffering to the families of the affected children and a huge burden to society. There is no shortage of such examples in China. Li Bai, the “poet immortal” of the Tang Dynasty, loved to drink heavily in his life and was known for his “hundred poems in a bottle of wine”. Although he himself is extremely intelligent, but the children born are either dumb or stupid, not only no one can inherit his natural poetic talent, even the ordinary people are not as good, so the Qing people have a poem said: “do not blame the chaff blame Dukang”, wine is the culprit of this tragedy. Three, coffee coffee and cola drinks contain a lot of caffeine, pregnant women too much caffeine intake (greater than 150mg / day), can affect the development of the fetal brain, heart and liver and other important organs, may lead to finger, toe deformities, while the chance of miscarriage, premature birth, baby underweight and other undesirable conditions increased. Fourth, stay up late Pregnant women stay up late for a long time, may lead to biological clock disorders and endocrine disorders, affecting metabolism and fetal development. Poorly developed newborns, the possibility of heart and lung disease will be greatly increased. Bad habits are closely related to birth defects in newborns, so expectant mothers and fathers should stop these bad habits for a period of time before considering conceiving a baby. There are different methods of withdrawal for different bad habits. Medication can be taken, such as smoking cessation drugs are available in major hospitals and pharmacies, and smokers can take them as prescribed by their doctors; alternative methods can be taken, such as drinking tea in moderation instead of the habit of drinking coffee. The most important thing is to have tough persistence and strong perseverance. I think, with determination, these bad habits can definitely be broken. I sincerely wish all the parents-to-be in the world a healthy and lovely baby!