What tests to do before pregnancy can detect genetic disorders

Chromosomal disorders. Diseases caused by abnormalities in the number and structure of chromosomes are called chromosomal diseases. At present, more than 300 chromosomal diseases have been known, and most of them are accompanied by a variety of birth defects such as growth retardation, mental retardation, malformations, and sexual development disorders.

Chromosomal disorders are not uncommon in the population.

X-linked genetic disorders.

The incidence of X-linked recessive genetic diseases is that female carriers themselves are asymptomatic or have very mild manifestations, while male carriers must develop the disease. If a female carrier marries a normal man, half of the boys may be sick and half normal, and the girls will be all normal, so the female fetus should be left after the prenatal diagnosis and the male fetus should be abandoned. If a male with X-linked genetic disorders marries a normal woman, the boy does not develop the disease, but the girl is heterozygous.

If the father is an X-linked dominant genetic disease and the mother is normal, both girls will develop the disease, so the male fetus is left behind after the prenatal diagnosis and the female fetus is abandoned.

Congenital errors of metabolism.

The body's material metabolism reaction is carried out with the participation of enzymes, if due to genetic defects caused by gene mutations, a certain enzyme can not be synthesized, or the amount or structure of synthesis is abnormal, resulting in a metabolic process is blocked or can not be carried out normally, that is, congenital metabolic defects. Most of the inborn errors of metabolism are autosomal recessive diseases, there are many types, although the incidence of each disease is very low, but the total incidence is considerable, the incidence of neonatal inborn inborn metabolism disease is about 8. The prenatal diagnosis of congenital errors of metabolism is mainly to check for biochemical abnormalities or enzyme changes in amniotic fluid or amniotic fluid cells, so it is necessary to have a full understanding of the biochemical nature of the disease when making prenatal diagnosis.

Prenatal diagnosis of the fetus can only be carried out for metabolic diseases with a completely clear biochemical nature, otherwise it cannot be performed. In the past, cultured or uncultured amniotic fluid cells and amniotic fluid supernatant were used mainly to diagnose metabolic defects, so prenatal diagnosis is possible only for metabolic defects that are manifested in amniotic fluid or amniotic fluid cells, which limits the scope of diagnosis. In recent years, the rise and development of genetic diagnosis has made genetic diseases have a more direct and effective means of diagnosis, which can be directly analyzed for DNA and also need to be examined for amniotic fluid.

In addition, chorionic villus testing can be performed in the first trimester, and cord blood puncture can be performed in the second and third trimesters.

Congenital malformations. Congenital malformations are multifactorial in which both genetic factors and environmental factors play a role. Common congenital malformations include cleft lip and palate, limb deformities, congenital heart disease, congenital pyloric stenosis, and lock-anus.

All of these diseases can be detected prenatally through counseling and prenatal diagnosis during pregnancy.

For the sake of eugenics, we recommend that couples who are trying to conceive should have a pre-pregnancy examination, and the best time is generally recommended to be 3 to 6 months before pregnancy, and both parties should be tested together. At the same time, in order to avoid fetal malformations, the woman can start taking folic acid three months before trying to conceive and continue to take it until three months after pregnancy. In order to prevent the birth of a child with a genetic disease, it is equally important to have a prenatal check-up after pregnancy.

Preconception chromosomal tests.

The most important feature of genetic diseases is that they are "hereditary" and will be passed on to offspring, so whether or not they need to be tested for genetic diseases depends to a large extent on whether there is a genetic disease in the couple's family.

If you need to be tested for a preconception genetic disorder:

1. There are relatives in the family of both husband and wife who suffer from genetic diseases;

2. Have given birth to or have given birth to children with genetic diseases and congenital malformations;

3. Have a history of unexplained infertility or habitual abortion in themselves or their family members;

4. Elderly couples: over 35 years old;

5. One of the husband and wife is engaged in high-radiation and high-risk chemical work.

Screening on time during pregnancy.

Several screenings that must be done during pregnancy:

1. Screening for children with Down's syndrome:

NT test: 11-13 weeks gestation +6;

Second trimester Tang screening: 16-20 weeks gestation;

Non-invasive DNA: 12 weeks gestation, 20 weeks + 6 days.

Amniocentesis: 18-26 weeks gestation.

2. Gestational diabetes screening: 24-28 weeks.

3. Fetal facial development, heart, brain, spine and other defects screening: four-dimensional color ultrasound examination: singleton pregnancy examination time is 20-26 weeks, twin pregnancy examination time is 20-24 weeks.

Hereditary disorders are diseases that are wholly or partially determined by genetic factors, often congenital, lifelong and familial. There are many kinds of diseases and high incidence. More than 3,000 genetic diseases have been identified, and it is estimated that about 3,100 out of every 100 newborns suffer from genetic diseases of varying severity.

So, maybe everyone carries at least one gene for a genetic disease, but fortunately, most genetic diseases require two matching genes to appear, one gene from mom and the other from dad, so genetic diseases are not easy to appear in children.

Both parents can be tested for a genetic disorder before or during pregnancy, but genetic screening is usually only meaningful if both parents are likely to carry a particular gene.

1.Preconception genetic counseling.

Preconception genetic counseling is essential. Genetic counseling means that the doctor will inquire and examine the medical history and family history, and then determine the genetic mode of the disease, analyze the risk of the disease, and provide guidance to the couple according to the physical characteristics and examination results of the counselor.

3.Premarital health check-ups.

Premarital check-ups are the beginning of mastering a good life. The first thing to do is to find out whether both parties have a serious family history of the disease. In addition to paying attention to the fact that close relatives are not allowed to get married, people with other diseases such as tuberculosis and viral hepatitis should not rush to get married and have children, and it is best to consider it after the illness has recovered.

3.Pay attention to prenatal screening.

That is, intrauterine diagnosis, detailed analysis of fetal appearance structure, chromosomes, genes, etc., to understand whether the fetus has congenital diseases or hereditary diseases, to prevent the birth of fetuses such as mental retardation and malformations. The optimal time for diagnosis is 15 to 20 weeks, and it is mainly used to screen for high-incidence genetic diseases, such as neural tube defects, congenital stupidity, trisomy 18, etc.

Correct understanding of genetic diseases].

1.First of all, learn to distinguish between genetic diseases and congenital diseases, which are caused by genetic factors, which are genetic diseases, such as Down syndrome; It is not a genetic disease, such as congenital heart disease, that is caused by external adverse factors. So, not so congenital diseases are all hereditary diseases.

Genetic diseases are caused by chromosome and gene mutations, and our common genetic diseases include hemophilia, thalassemia, color blindness, albinism and so on.

2.Although genetic diseases are congenital, it does not mean that the baby is born with the disease, and some diseases have an incubation period and need to be developed at a certain age. For example, hereditary mental retardation is often difficult to detect in infancy.

The root cause of this type of genetic disease is in the embryonic stage, so the responsibility lies with the parents. Therefore, during pregnancy preparation and pregnancy, couples must do a good job in the prevention of genetic diseases to ensure eugenics.

Genetic diseases refer to genetic diseases of germ cells or fertilized eggs, and women need to do a comprehensive examination during the preparation for pregnancy to see if there are recessive or dominant genetic diseases, if so, please be cautious about pregnancy.

Both parents need to go to the hospital for routine check-ups before pregnancy, and as people pay more and more attention to the quality of fertility, pre-pregnancy check-ups have become a must-have for expectant parents. So what do you need to check to get pregnant?

1. Urinalysis.

The main purpose of the urine routine examination is to diagnose whether there is a hidden kidney disease, and the burden on the kidneys increases during pregnancy, and if the condition worsens with pregnancy, it may cause miscarriage, premature birth and other distressing things. The urinalysis does not need to be fasted, and the first mid-length urine test is taken in the morning.

2. Blood routine.

The main purpose of the blood routine is to check the hemoglobin value, white blood cells, platelet content, etc., and to confirm whether there is any potential danger such as anemia. If the iron content is insufficient during pregnancy, the fetus cannot be provided with nutrition in time, which will affect the development of the fetus and postpartum recovery.

3. Chromosomes.

The chromosomal test is the most important test, and chromosomes are related to all aspects of the fetus. A chromosomal examination can reveal the number of DNA, whether it is abnormal, sex, and some infertility problems. If a woman has a history of recurrent miscarriages, malformations of the baby during pregnancy, or certain genetic conditions, doctors may order chromosomal tests, which can be detected early and can be effectively intervened.

Before pregnancy, it is necessary to check whether there are liver and kidney function problems, hepatitis B, hepatitis C and other syphilis, ** diseases and so on. These problems can cause infection during fetal development or birth, so some exclusion tests should be done before pregnancy.

Before preparing for pregnancy, it is necessary to do a comprehensive physical examination to see what is unhealthy, and what is the most serious genetic disease, one is the liver, and the other is the lungs. There are also large pieces of the body such as the heart. These are particularly important.

Heart disease: If a parent has heart disease, the chance of a child developing heart disease is 5-7 times higher than that of a parent without heart disease.

Carcinoma: Melanoma is an uncommon but very deadly form of cancer.

It is mainly to collect blood for laboratory tests to detect whether there are some genetic diseases, as well as infectious diseases. In addition to the eight items of eugenics, women should also have an ultrasound examination to evaluate ovarian function, fallopian tube patency and uterine status.

For example, if you have heart disease, diabetes, allergies, asthma, etc., you should also check the blood routine and urine routine.

Since pregnancy, most expectant mothers will choose to do a variety of tests for the health of their children, some of which can understand the physical condition of the expectant mother, and some can understand whether the fetus has a possibility of genetic disease. So how long does it take to get pregnant to check for genetic diseases? Next, I will introduce it to you in detail, I hope it can help you.

I've also put together some content on genetic diseases during pregnancy, so if you are interested, you can check it out.

OK. Amniotic fluid tests are usually performed between 16 and 20 weeks of gestation, and amniocentesis is performed with amniotic fluid. Examination items include cell culture, sex chromosome identification, karyotype analysis, amniotic fluid alpha-fetoprotein determination, amniotic fluid biochemical examination, etc., to determine the maturity and health of the fetus, and to diagnose whether the fetus is normal or has certain genetic diseases.

Amniotic fluid examination can diagnose the following diseases and plays an important role in eugenics.

1. NT is the nuchal translucency, commonly speaking, it is a zona pellucida behind the fetal neck, NT examination is best carried out between 11 and 14 weeks of pregnancy, NT is not seen too early, then the abnormal fetal NT will disappear too late, this window period is very precious. NT is the most sensitive indicator for early detection of fetal abnormalities, belonging to imaging B ultrasound examination, once NT is abnormal, then there is a 1 6 chance that the fetus is chromosomal abnormal.

2. Tang screening examination is divided into early Tang screening and mid-stage Tang screening, the early stage is in 11-14 weeks, because it needs to be combined with imaging and serological examination, and the cost will be relatively high, so there are fewer hospitals to carry out. The vast majority of hospitals carry out the second trimester pregnancy screening, at 15-20 weeks, the blood of pregnant women is drawn, and the blood is tested for HCG, UE3, AFP, and IHA, and the risk of fetal chromosomal abnormalities is calculated by calculating the level in the general population.

3. Amniocentesis is to extract the free fetal cells from the amniotic fluid of the pregnant woman for chromosomal examination, so as to confirm the diagnosis of ulnardom or rule out the chromosomal abnormality of the fetus.

Introduction: Although genetic diseases are scary, if they are prevented early, they can be relatively harmless. Therefore, expectant mothers should do their homework before becoming pregnant and understand the family history of genetic diseases of both partners so that they can prepare in advance and take measures.

If one parent has high blood pressure or hypertension, the incidence rate for the child is about 50%. If both parents have high blood lipids or high blood pressure, the child has a 75% chance of getting the disease. In addition, if one of the grandparents has heart disease, the chances of the child getting sick are also very high.

Tip: In addition to regular check-ups, it's important to control your child's intake of fats and sweets. After the age of 1, it is necessary to ensure that his students have a balanced diet every day, keep exercising, and avoid accumulating too much fat.

In addition, studies have shown that breastfeeding can reduce the risk of hyperlipidemia in your child, so it is important to breastfeed as much as possible.

If one parent has long-term ear inflammation, there is a 60% 70% chance of passing it on to the child. Because the shape of the parent's face or the structure of the Eustachian tube is likely to be passed on to the child, children with this gene are more likely to develop otitis media. If one of the pregnant couples suffers from ear inflammation, then it is important to stay away from cigarettes from the beginning of pregnancy, not only not to smoke by yourself, but also to try to stay away from the poison of secondhand smoke.

If the woman's ears are inflamed, try to cure them before conception to avoid adverse effects on the fetus.

If one of the parents is severely obese, i.e., obese, the child is 40% overweight; If both parents are obese, the child is up to 70% likely to be obese. Experts remind that the problem of overweight in childhood cannot be ignored as it is likely to lead to diabetes, early heart disease, asthma and cancer. Recommendations:

Parents should first lead by example by developing healthy eating and exercise habits. Children drink less sugary drinks and watch TV for no more than 2 hours a day. After the child is 2 years old, the body should be checked regularly, and the doctor will judge whether the overall index is normal, so as to detect whether the child's weight is wrong as soon as possible.