Pregnancy and childbirth is a big event for any family, especially with the abolition of mandatory premarital checkups and the increased awareness of eugenics, more and more people are aware of the importance of pregnancy preparation and preconception checkups, and couples of childbearing age are taking the initiative to go to hospitals for physical examinations. Since there are many medical units that perform preconception checkups, the standard of care varies, leading to confusion in choosing the test items. For most couples without a history of poor fertility, a healthy lifestyle, abandoning bad habits and going to the hospital for routine preconception checkups are sufficient. However, for those who have a history of poor fertility or a family history of genetic disorders, it is important to choose the right preconception screening program. Today, we will briefly introduce this topic in the hope that it will be helpful to those who are preparing for pregnancy. 1. Adopt a healthy lifestyle and maintain a calm state of mind in preparing for pregnancy A healthy lifestyle mainly means no smoking, no alcohol abuse, no late nights, proper exercise and reasonable nutrition. Pregnancy requires time and patience. Under normal circumstances, it is not necessary to “count the days and pinch the time”, but excessive tension is not conducive to conception, which is counterproductive. For a woman with a normal menstrual cycle (28-30 days), ovulation is around the 14th day of menstruation, and this is the time when the chances of conception are highest. Avoid contact with toxic and harmful chemical and physical environments before and during early pregnancy, and keep women of childbearing age away from pets and raw meat as much as possible. 2, eugenics, starting with quitting smoking The need for women to quit smoking has become a generally accepted view. We know that if a woman smokes, it is likely to cause menstrual disorders and reduce the chances of conception. After pregnancy, if a woman does not quit smoking, the harmful substances in tobacco can endanger the developing embryo through the placenta, especially in the early stages of embryonic development, and there is a close relationship between maternal smoking and fetal chromosomal abnormalities, miscarriage, stillbirth, multiple malformations and intrauterine growth retardation. In addition, pregnant women who smoke are more likely to suffer from anemia, and it is more common for them to have insufficient breast milk after delivery. So does the male partner need to quit smoking? In my consultations, I often encounter couples arguing about whether the male partner needs to quit smoking or not, which is frustrating. Smoking is also very harmful to men. Smoking has a negative impact on male fertility, and the sperm density, sperm motility, and normal sperm rate of smokers are significantly lower than those of non-smokers, which increases the risk of male infertility. In addition, the harmful substances in tobacco can affect sperm DNA, causing changes in the genetic material of male sperm, which in turn increases the risk of malformed embryos. If the male partner must find 10,000 reasons for smoking, then please do not smoke in front of his wife, so that “second-hand smoke” does not become a hidden danger to the fetus. 3.What do I need to take during pregnancy preparation? In addition to a healthy diet, couples are generally recommended to take 0.4 to 0.8 mg of folic acid 3 months before conception, or multivitamins containing folic acid if economic conditions allow, in order to prevent fetal neural tube defects and other birth defects. As for how to properly supplement folic acid, we have already introduced it before, so you can learn about it. 4.How to choose the screening program for a healthy couple? If a healthy couple has no history of bad fertility or familial genetic disease, the following items can be selected for general checkups. The female partner includes gynecological examination (preferably including cervical cancer screening and HPV testing), gynecological ultrasound, sex hormone testing, thyroid function test, routine leukorrhea, urine routine, blood routine, blood type, liver function and hepatitis virus index test, etc. In addition to the general routine examination, the male partner is recommended to have a semen examination if he has the habit of smoking, drinking alcohol and staying up late. If the couple is negative for hepatitis B surface antibody, it is recommended to have a hepatitis B vaccination six months before pregnancy. Special tests generally include couple chromosomes, screening for thalassemia, determination of folic acid levels, and the five eugenic tests (TORCH), which are antibody tests for a group of pathogenic microorganisms (i.e. Toxoplasma gondii, rubella virus, cytomegalovirus and herpes simplex virus) whose primary infection during early pregnancy may cause perinatal infections leading to miscarriage, stillbirth, premature birth, The purpose of preconception testing is to understand the risk of pregnancy. The purpose of preconception testing is to understand a woman’s infection and immune status and to provide appropriate guidance. If the rubella virus antibody IgG(-) is present, we recommend preconception rubella vaccination and strict contraception for 3 months. 5. How should couples with a history of adverse fertility choose their screening program? Adverse fertility history covers a wide range of types, and common questions in genetic counseling include: recurrent miscarriage, stillbirth, history of pregnancy with abnormal fetuses (congenital heart disease, polydactyly, polydactyly, cleft lip and palate, hydrocephalus, clubfoot, neural tube defects, short limb deformities, abnormal development of external genitalia, etc.) and history of birth to children with intellectual disabilities. Due to the limited space, it is not possible to introduce all the problems, so we will focus here on the two more common types of outpatient C recurrent miscarriage and the birth history of children with mental retardation, and how these couples should choose their screening programs. The medical definition of recurrent miscarriage is the occurrence of ≥3 miscarriages with the same sexual partner before the 24th week of gestation, whether consecutive or not, also called habitual miscarriage. In practice, we consider two spontaneous miscarriages as recurrent miscarriages, and two or more spontaneous miscarriages should be examined to determine the cause of miscarriage. Generally, about 50% of recurrent miscarriages can be detected by examination, including chromosomal abnormalities, uterine malformations, uterine vascular abnormalities and local circulatory disorders, luteal insufficiency, elevated prolactin, polycystic ovary syndrome, thyroid disease, immune factors and infectious factors of the reproductive tract. Therefore, couples with a history of recurrent miscarriage pregnancy should undergo the above-mentioned tests before conception to clarify the cause and then target prevention and treatment. It should be noted that the most common cause of spontaneous miscarriage is chromosomal abnormality of the embryo itself, which accounts for 60% of spontaneous miscarriages. It is advisable to preserve embryonic tissues after spontaneous miscarriage and perform chromosomal analysis to determine whether the spontaneous miscarriage is due to chromosomal abnormality of the embryo itself. Mental retardation is a condition often encountered in genetic counseling. Mental retardation refers to the developmental process (before the age of 18) in which mental function is significantly lower than that of the same age and social adaptation is significantly impaired, with a prevalence of 1% to 3% in the population. Many couples have the misconception that since their first child has already developed the disease, they can just check the fetus in the womb after another pregnancy. In fact, this is a very wrong understanding, because the causes of mental retardation are very complex, external environmental factors account for about 1/3, including malnutrition during pregnancy, perinatal infection, hypoxia, trauma, premature birth, neurotoxic drug exposure, etc.; internal genetic factors account for about 2/3, including chromosomal abnormalities, monogenic diseases, polygenic diseases, genetic metabolic diseases, etc.. We can only guide couples to have children again after clear diagnosis of children who have already developed as much as possible, and also to minimize the risk of them having children with mental retardation again. 6. Pre-conception testing for couples with a family history of genetic disorders? This type of couple is also one of the more common cases in our genetic counseling clinic. There are many types of genetic diseases and the diagnosis of each genetic disease is different. In these cases, it is recommended that couples must consult a professional genetic counseling clinic or prenatal diagnostic facility before conceiving, so as not to blindly conceive and risk having another child with a genetic disorder. Common genetic disorders include congenital deafness, thalassemia, phenylketonuria, sericea, pseudohypertrophic progressive muscular dystrophy, spinal muscular atrophy, albinism, hemophilia, Marfan syndrome, chondrodysplasia, polycystic kidney, congenital adrenal cortical hyperplasia, etc. We must first perform genetic diagnosis in patients who have already developed the disease (called pre-disposers in genetic counseling), identify the causative gene in pre-disposers and perform a family line analysis before we can assess the risk of reproduction in other members of the family and, if necessary, use prenatal diagnosis techniques during pregnancy to avoid the birth of a diseased fetus. Friends, the complexity of the causes of birth defects makes the diagnosis of genetic diseases challenging. It is believed that with the development of science and the improvement of diagnostic technology, more and more genetic diseases will be clearly diagnosed. Only then can scientific guidance be given to healthy childbirth. We also hope that more couples will participate in the prevention of birth defects to protect the health of their babies.