The long-awaited era of two children has finally arrived. How to do a good job of pre-pregnancy preparation and as soon as possible to give birth to two children has become the most concerned topic. But in the opening of the two children “dad” before, these steps can not save: First, the man’s pre-pregnancy examination: 1, semen examination is to determine the man’s fertility is the most basic and is the most important method, mainly including sperm count, vitality, morphology, sperm acrosome function, sperm nuclear DNA fragmentation and infection indicators. It is best to abstain from sex (no ejaculation behaviors such as intercourse or masturbation) for 3 to 5 days before coming to the hospital for semen examination, as too short or too long an abstinence period can cause inaccurate semen test results. Increasing age, bad habits such as staying up late and smoking and drinking, high work pressure, environmental pollution, diabetes and other underlying diseases can have a cumulative effect on male fertility, resulting in poorer sperm quality and reduced sexual function. It is relatively common that it is easy to give birth to the first child but difficult to give birth to the second child. In particular, “advanced” fathers over the age of 40 are more likely to have decreased sperm fertilization and higher rates of sperm nuclear DNA fragmentation, which can lead to difficulties in conceiving naturally and increased risk of fetal miscarriage, making it even more important to have a preconception semen test. When an abnormal semen test is detected, it is important to treat it under the supervision of a male physician. At present, most of the semen abnormalities can be improved or cured by reasonable treatment. 2.Sexual function assessment. With age, many men experience sexual dysfunction such as decreased libido, erectile dysfunction, premature ejaculation or ejaculatory difficulties, which can cause discord in the couple’s sex life, affect the couple’s relationship, and in serious cases, cause infertility. To determine whether a man’s sexual function is normal or not, it mainly relies on the male doctor to ask about the performance of the male partner during sex, and if necessary, sex hormone and other tests can be done. At present, most of the sexual dysfunction can be improved or cured through reasonable treatment. 3.Peripheral blood karyotype of both husband and wife. Chromosome karyotype is a basic indicator reflecting whether the human genetic material is normal or not. Parents with abnormal chromosome karyotype will have a much higher probability of serious chromosome abnormality in their offspring than normal people, and they are especially prone to fetal malformation and miscarriage. Even if you have already given birth to a healthy offspring, it does not mean that the parents’ karyotype must be normal, because parents with abnormal karyotype have the probability of giving birth to a healthy offspring when they have good luck, so will they still have good luck when they give birth to their second child? It is better to take a checkup for peace of mind, and the results will be valid for life. Even if the test reveals abnormal karyotype, it is not scary because the third generation IVF technology can help parents with abnormal karyotype to choose to have healthy offspring with normal karyotype. 4.Thalassemia gene mutation test. Thalassemia is caused by mutation of human bead protein gene, including α and β types. Fetuses with α thalassemia are prone to intrauterine deaths in the middle and late stages of pregnancy or deaths after preterm delivery, and other adverse pregnancy outcomes; β thalassemia can lead to fetal death or disability. Couples carrying a genetic mutation in the thalassemia gene may not develop the disease themselves, but the risk of developing the disease in their offspring is greatly increased. Therefore, in areas with high incidence of thalassemia, such as Guangdong Province, Guangxi Province and Hainan Province, couples of childbearing age should be tested for thalassemia gene mutation, and at the same time, with pre-implantation genetic diagnosis (PGD) or prenatal diagnosis, the birth of thalassemia-affected children can be prevented. 5. Sexually transmitted disease examination, mainly including syphilis, AIDS, herpes virus and chlamydia examination. Men who have prostitutes and other unclean sexual behaviors are advised to go to the STD department of a regular public hospital for a checkup before having a second child. When STDs are found, they must be treated in time so as not to affect the woman’s pregnancy and the health of the next generation. Second, adjust habits and diet, away from the harmful environment: stay up late, smoking, alcohol and other bad habits will cause men’s fertility to decline, increase the risk of fetal malformation and miscarriage. Because the sperm production cycle is about 3 months, so the father of the second child of the family planning, it is best to start 3 to 6 months in advance to adjust their habits, scientific and reasonable diet and away from harmful environments, commonly known as the “closed mountains and forests. 1, do not stay up late. Staying up late and not getting enough sleep has become the number one killer of male reproductive health. Staying up late can lead to spermatogenic dysfunction, resulting in reduced sperm count, poorer vigor, higher deformity and DNA fragmentation rates, which can easily lead to male infertility and female miscarriage. Often stay up late will also lead to male reproductive endocrine disorders and decreased immunity, causing low libido, impotence, premature ejaculation and other sexual dysfunctions, easy to suffer from chronic prostatitis and epididymitis. Men should avoid staying up late, go to bed before 11:00 p.m., to ensure that 11:00 p.m. to 7:00 a.m. these 8 hours of effective sleep time. 2, quit smoking. Smoking can cause a reduction in sperm count, sperm cell membranes and DNA damage, long-term smoking or inhaling second-hand smoke can easily cause male infertility and impotence, female miscarriage and fetal malformation. Some studies have shown that quitting smoking can improve semen quality. 3. Drink less alcohol. Excessive alcohol consumption can affect sperm production and development and maturation, leading to a decrease in sperm fertilization ability, and may also cause low libido, impotence, premature ejaculation and other sexual dysfunctions, which are prone to cause male infertility. It is recommended to drink less alcohol, especially do not drink high liquor and foreign wine. 4, avoid sedentary. Sedentary or cycling, driving and other behaviors will make men sit for too long, will cause the male reproductive organs (testicles, epididymis, prostate and seminal vesicle glands) blood circulation is not good, so that men are prone to chronic prostatitis and epididymitis; will also cause the testicular temperature will rise, directly damage the testicular spermatogenesis, which will lead to a decline in the quality of spermatozoa. It is recommended that sedentary men stand up and move around for a while at least every half an hour. 5. Avoid high temperature. The proper temperature required for testicular sperm production is 1~2 degrees lower than the body temperature (35.6℃~36℃, and the temperature exceeding 37℃ will damage the sperms), and high temperature will seriously damage the spermatogenic function of testicles. Men in their reproductive years should try to avoid wearing tight underwear and thick pants, soaking in hot springs, saunas, placing laptops directly on their knees and other behaviors, and avoid working in kitchens, boiler rooms and other hot environments. 6, moderate physical exercise and sports. Daily exercise for half an hour to one hour, such as jogging or walking, is helpful for improving sexual function and fertility. But don’t be too fatigued, because too intense exercise will lead to endocrine disruption and decreased immunity. 7. Reasonable diet. The production and development of sperm requires the intake of sufficient protein, vitamins and trace elements. Genetically modified foods may cause sterility, and spicy foods can easily induce prostatitis and other diseases. Therefore, men should eat more eggs, milk, beef, lamb, corn, walnuts, oysters, apples and tomatoes and other fresh fruits and vegetables, and try to avoid spicy food and genetically modified food. 8, avoid contact with toxic chemicals and radiation. x-rays, marble release of excessive rays, chemotherapy drugs, pesticides, insecticides, paints, formaldehyde, benzene, heavy metals (such as aluminum, lead, cadmium, mercury, etc.), welding, printing and dyeing and plastics manufacturing and other work environments, which may result in a decline in the number of spermatozoa and vitality, deformity rate and DNA fragmentation rate increased, seriously impairing male fertility, should try to avoid exposure. 9, avoid excessive exposure to electromagnetic radiation. Sperm is very sensitive to electromagnetic radiation, too much exposure to electromagnetic radiation will cause a decline in sperm quality and sperm DNA damage, may cause male infertility and female miscarriage. It is recommended not to turn on the wireless Internet function of the cell phone and computer placed too close to the scrotum, do not stay too long in the WiFi transmitter, electromagnetic wave transmission towers, high-voltage substations, radar stations and other electromagnetic radiation near the strong equipment. 10, avoid emotional tension and anxiety. Mental stress will affect spermatogenesis and sexual function through the neuroendocrine system, resulting in decreased sperm quality and sexual dysfunction. Men should learn to reduce stress and regulate their emotions, and maintain a comfortable mood, which is conducive to improving sexual function and semen quality. Third, adequate and regular sex life: adequate and regular sex life is not only conducive to men to maintain good sexual function and improve the quality of sperm, but also can improve the success rate of natural pregnancy. Couples trying to get pregnant, as long as the woman is not in the menstrual period, it is best to adhere to every 3 to 4 days of sexual intercourse 1 time, is conducive to improving the success rate of pregnancy. Women are most likely to get pregnant during ovulation, and can have intercourse every two days during ovulation to increase their chances of getting pregnant. Under normal menstruation, from the first day of the next menstrual period, counting down 14 days is the “possible day of ovulation”, 5 days before the day of ovulation and 4 days after the day of ovulation, including the day of ovulation, a total of 10 days is known as the period of ovulation. It is recommended that the woman use “ovulation test paper” to monitor ovulation, which can more accurately determine the day of ovulation. Fourth, if necessary, the use of assisted reproductive technology: the man after the above preparations, you can try to get pregnant. But do not use contraception and try to get pregnant for more than one year, the woman is still not pregnant, even if the infertility. At this time, we should come to the Center for Reproductive Medicine as soon as possible, and if necessary, we can choose artificial insemination and IVF and other assisted reproductive technologies under the guidance of the doctor to improve the success rate of pregnancy.