amniocentesis

Amniocentesis, also called sheep choriocentesis, is a prenatal diagnosis method. It takes amniotic fluid samples from pregnant women to check whether the fetus has chromosome problems. The best time for amniocentesis is pregnancy 16 ~ 20 weeks. Because of the need to puncture into the amniotic cavity, there is the possibility of abortion and fetal injury.

What symptom is amniotic fluid broken?

Generally speaking, women can be prepared to have children in the third trimester. Pay attention to amniotic fluid at this time. What are the symptoms of amniotic fluid rupture in the third trimester?

If you can't tell whether it is urine leakage or water leakage, you can check it with test paper. Specifically, it is to stick the test paper on underwear and distinguish whether it is amniotic fluid or urine from the color change. The pH value of amniotic fluid is 7.0 to 7.5, and the pH value of urine is 5.5 to 6.5. If it is a blue test paper, urine turns red and amniotic fluid does not change color. If it is a red test paper, the amniotic fluid turns blue and the urine has no color change.

Some pregnant mothers, after finding themselves in water, want to take a bath and wait for their baby comfortably. However, bathing requires standing to accelerate the outflow of amniotic fluid, which is also easy to cause bacterial infection and increase the risk. When the water breaks, you should see a doctor quickly, regardless of contractions.

Matters needing attention after amniocentesis

There are many things that women need to pay attention to after amniocentesis, so what should they pay attention to after amniocentesis?

Amniocentesis is an invasive prenatal diagnosis. Premature sexual intercourse after operation will make it easier for bacteria to enter the vagina, which invisibly increases the risk of infection and may also induce some inflammation such as endometritis. Most importantly, it will increase the possibility of miscarriage or premature delivery, which is not good for the fetus.

After amniocentesis, there will still be wounds on the stomach. Pregnant mothers should pay attention to the wound not to be infected. You'd better take a bath before the operation. Husband and wife are forbidden to live for the first three days, and they can't take a shower and share the same room after surgery. If the abdomen has been uncomfortable, there is a feeling of falling, or there is red secretion in the vagina, pay attention to whether you have a fever or see a doctor as soon as possible.

amniocentesis

During the check-up, many expectant mothers talked about "pricking" and felt that amniocentesis was a terrible thing. What should I do if my baby has a miscarriage? Therefore, even though amniocentesis is currently recognized as the "gold standard" for prenatal diagnosis of chromosomal diseases, many expectant mothers in need are still discouraged and entangled. What exactly is amniocentesis? Should I do it? What are the risks? With these doubts, today I will reveal the mysterious amniocentesis for you.

What is amniocentesis?

Amniocentesis, also known as amniocentesis, is a method of prenatal diagnosis, which is usually carried out in pregnancy 16-22 weeks. At this time, the outline of the uterus is clear, the amount of amniotic fluid is relatively large, it is easy to extract, it is not easy to harm the fetus, amniotic fluid cells are easy to survive, and the success rate of culture is high. The method of amniocentesis is that under the real-time monitoring of ultrasound, a fine needle passes through the pregnant woman's abdomen, through the uterine wall and into the amniotic cavity, and 20 ml of amniotic fluid is extracted, and fetal cells in amniotic fluid are collected. After two weeks of culture, special treatment is carried out to obtain fetal chromosomes for karyotype analysis.

What can amniocentesis check? How accurate is it?

Because all fetal chromosomes can be collected and analyzed through genetics, we can not only know the abnormal number of fetal chromosomes, but also diagnose structural abnormalities, so the diagnosis range is very wide, covering basically all chromosomal diseases, and at the same time, we can also detect whether there is maternal-infant blood group incompatibility, intrauterine infection, congenital metabolic abnormality, fetal maturity and so on, with an accuracy rate of over 99%.

Is amniocentesis risky?

Amniocentesis is an invasive diagnosis of fine needle entering the amniotic cavity, which has certain risks and may lead to complications such as abortion and infection, but don't worry too much. The incidence of abortion after puncture is about 0.5%, which is not only related to the constitution and gestational age of pregnant women, but also related to the experience of puncture doctors and ultrasound doctors. Ultrasound-guided amniocentesis, real-time monitoring, can clearly see every part of the fetus, will not hurt the baby. Amniotic fluid extracted during amniocentesis is less than 8% of the total amniotic fluid, which will be replenished soon, so there is no need to worry about the decrease of amniotic fluid after amniocentesis. This technology has been used for prenatal diagnosis for more than 30 years, with high accuracy and safety.

Does everyone need amniocentesis?

That's not true. Amniocentesis is not a routine examination item, and it will only be done when necessary. Include the following personnel:

① Older pregnant women ≥ 35 years old;

② Down's screening for high-risk pregnant women without puncture contraindication;

③ One of the husband and wife is a patient with chromosome diseases, or a pregnant woman who is pregnant or has given birth to a child with chromosome diseases;

④ Abnormal pregnant women were found by ultrasound screening;

Pregnant women with abnormal DNA test.

Amniocentesis is a common obstetrical examination, and the cost is about 1000 yuan (the fees vary slightly in different regions and hospitals). It is recommended to fully weigh the pros and cons before making a decision. If pregnant women are selected for testing, it is suggested to choose a regular large hospital with prenatal diagnosis qualification for surgery under the condition of good conditions and suitable gestational age (preferably 16 ~ 22 weeks). Generally speaking, the risk of amniocentesis is lower than the incidence of spontaneous abortion, so expectant mothers who need to be examined need not worry too much.

What is amniocentesis?

Amniocentesis is a prenatal diagnosis method. After amniocentesis, a very small amount of amniotic fluid is extracted for analysis. It is usually used as an auxiliary examination for Down's screening and the judgment of some genetic diseases. During pregnancy 17-2 1 week, the living cells in amniotic fluid reached 30%, and the success rate of cell culture was high. At this time, there is more amniotic fluid and the fetus is small, so it is not easy to stab the fetus, so it is the best time to do amniocentesis. Amniocentesis, specifically, is to puncture the uterus with a puncture needle through the abdominal wall of the expectant mother, suck out about 20ml of amniotic fluid samples, and then get the chromosome karyotype by amniotic fluid culture on the 7th-14th day, and then observe and analyze whether the chromosome will be distorted, so as to get the risk value of whether the fetus is Down's child.

Amniocentesis, what to do? Not doing it? What are the symptoms before and after amniocentesis?

Generally speaking, women can be prepared to have children in the third trimester. Pay attention to amniotic fluid at this time. What are the symptoms of amniotic fluid rupture in the third trimester?

If you can't tell whether it is urine leakage or water leakage, you can check it with test paper. Specifically, it is to stick the test paper on underwear and distinguish whether it is amniotic fluid or urine from the color change. The pH value of amniotic fluid is 7.0 to 7.5, and the pH value of urine is 5.5 to 6.5. If it is a blue test paper, urine turns red and amniotic fluid does not change color. If it is a red test paper, the amniotic fluid turns blue and the urine has no color change.

Some pregnant mothers, after finding themselves in water, want to take a bath and wait for their baby comfortably. However, bathing requires standing to accelerate the outflow of amniotic fluid, which is also easy to cause bacterial infection and increase the risk. When the water breaks, you should see a doctor quickly, regardless of contractions.

Amniocentesis for what?

After pregnancy, we should be scientific in nutrition, control the intake of fat, sugar and salt, and prevent pregnancy complications; At the same time, pay attention to prenatal diagnosis and abnormal examination; It is recommended that pregnant women over 35 years old have routine amniocentesis. Amniocentesis. What?

1, diagnosis of chromosome, genetic disease and metabolic disease, diagnosis of congenital stupid children, and preparation for subsequent fertility intervention;

2. Diagnose whether the fetus has open neural tube defects, such as anencephaly or spina bifida;

3. Check the maturity of fetal lung, kidney, liver and skin;

4. Predict fetal blood type and diagnose whether neonatal hemolysis will occur;

5. Detection of intrauterine infection, such as the increase of interleukin -6 in amniotic fluid, may have subclinical intrauterine infection;

6, to assist in the diagnosis of premature rupture of membranes, premature rupture of membranes due to alkaline amniotic fluid, pH value should be greater than 7.

Necessity of amniocentesis

Does amniocentesis have to be done? The necessity of amniocentesis deserves attention. Amniocentesis is not necessary for Down's screening of low-risk expectant mothers, because amniocentesis has certain risks. For expectant mothers who are at high risk of screening for Down's syndrome in the middle term, it is necessary to have amniocentesis to confirm whether the fetus is Down's syndrome. Only through amniocentesis can the probability of birth defects be minimized.

Which pregnant women need amniocentesis?

It is best for expectant mothers who meet the following conditions to have amniocentesis:

1, ultrasound examination suspected fetal malformation such as neural tube defect or abnormal high alpha-fetoprotein in maternal blood;

2. Some pathogens are infected during pregnancy, such as rubella virus, cytomegalovirus or toxoplasmosis;

3. Pregnant women who have given birth to congenital defects, especially chromosomal abnormalities;

4. Both husband and wife have the possibility of chromosome abnormality;

At the time of delivery, the expectant mother is over 35 years old.

When is amniocentesis done?

The best time for amniocentesis is in pregnancy 17-2 1 week. At this time, there is more amniotic fluid and the fetus is small. When extracting amniotic fluid by acupuncture, it is not easy to stab the fetus, and extracting 20-30 ml of amniotic fluid will not have adverse effects on the development of the fetus. The most important thing is that there are many living cells in amniotic fluid during this period (which can account for 30%), and the success rate of cell culture is high.

How to do amniocentesis?

How to do amniocentesis? The steps of amniocentesis are as follows:

1, expectant mothers with indications should first do B-ultrasound to determine the position of placenta and fetal condition, so as to avoid accidental injury to placenta;

2. After selecting the needle entry point, disinfect the skin, spread a disinfectant towel, perform local anesthesia, and puncture vertically at the selected point with a waist needle with a needle core;

3. When the needle passes through the abdominal wall and uterine wall, it feels lost twice, and the needle core is taken out;

4. Suck out 2 ml amniotic fluid with 2 ml syringe and discard it. Obviously, this amniotic fluid may contain maternal cells;

5. Absorb 20 ml amniotic fluid with 20 ml empty needle, put them in two sterilized test tubes respectively, and cover them;

6. Take out the needle, cover it with sterile gauze, press it for-minutes, and the expectant mother will stay in bed for 2 hours;

7. Amniotic water was cultured for 7- 14 days to obtain the chromosome karyotype, and then the chromosome aberration was observed and analyzed.

Risk of amniocentesis

Does amniocentesis hurt?

Amniocentesis is generally not too painful, but it varies from person to person. Some expectant mothers are sensitive or nervous about pain and may feel pain.

Anesthesia is not needed in amniocentesis, because the pain of injecting anesthetic may be stronger than amniocentesis itself. Most expectant mothers will only feel slight pain when they just have a puncture, which is similar to the pain of pricking their fingers to take blood, and it is tolerable pain. There is no need to worry about the harm to the fetus. In this process, the doctor will carefully avoid the fetus under the supervision of B-ultrasound.

Because no anesthetic is used, some expectant mothers may feel a little tight in the abdomen during amniocentesis, or they may feel tingling or oppression, and some expectant mothers may not feel any discomfort. Whether they feel pain or not depends on their personal situation.

Risk of amniocentesis

Amniocentesis is carried out under the guidance of B-ultrasound, and doctors will choose the position where amniotic fluid is rich and does not harm the fetus, so it is generally very safe.

With the continuous progress of technology and clinical technology, the safety factor of amniocentesis has been greatly improved. Take the abortion that expectant mothers are most concerned about as an example. It was reported in the last century that the abortion rate was about 0.5%( 1/200). In recent years, it has been reported that the abortion rate caused by it is only11600. However, as an invasive examination, no one can guarantee that amniocentesis will not have any influence on fetus and expectant mother. In addition, the main complications of amniocentesis include bleeding, infection, amniotic fluid leakage, respiratory distress, premature delivery, fetal injury, abortion and so on.

Complications of amniocentesis

1, blood infection: expectant mothers have a certain chance of touching fetal blood. When contact occurs, if the blood of the expectant mother is Rh negative and the blood of the fetus is Rh positive, there will be danger.

2. Infection: If the expectant mother is infected, bacteria may be brought into the amniotic sac during amniocentesis. Infection can cause high fever, uterine contraction and/or abdominal pain, but this is very rare.

3. Water breakthrough: incidence 1%, self-healing within a few days.

4. Amnionitis: The incidence rate is 0. 1%, which will cause symptoms such as lower abdominal pain and fever, and it is very easy to give birth prematurely.

5. Vaginal bleeding: The incidence rate is 1%-2%, and it will improve itself within a few days.

6. Fetal stab wound: It rarely happens under the guidance of ultrasound. Occasionally, the fetus will suddenly move, and the doctor can avoid it immediately. If you are accidentally stabbed, it will not have much impact and will heal itself.

7. Respiratory distress: A few studies have found that the fetus who has received amniocentesis is more prone to respiratory distress after birth, the incidence rate is 1. 1%, and the fetus who has not received amniocentesis is 0.5%.

Does amniocentesis need an empty stomach?

Amniotic fluid examination generally does not need an empty stomach, because the living cells and serum on amniotic fluid are not affected by diet, but it is best to go in the morning, because puncture cannot be done immediately after registration, and some tests need to be done, such as temperature measurement, fetal heart rate and B-ultrasound. Determine the position of placenta, fetal condition and amniotic fluid condition, and then decide whether to perform puncture.

Precautions before amniocentesis

1. If you have any abnormal conditions such as cold, fever and skin infection 3-7 days before operation, please inform the doctor when you register before operation.

2. If you have a history of allergies, special diseases and other things that need to be explained, please inform the doctor when you register before surgery.

Matters needing attention after amniocentesis

1, sit quietly for at least 2 hours after operation, and then go home by car; It is best for foreign patients to rest near the hotel in the hospital that night and go home the next day to avoid being too tired after surgery.

2. Pay attention to rest after operation and avoid physical labor such as strenuous exercise and carrying heavy objects.

3. If abdominal pain, bloating, vaginal discharge, bleeding, fever and other symptoms occur within three days after operation, you should go to the hospital for obstetrics and gynecology immediately.

Reference range of amniocentesis

The reference range of amniocentesis mainly depends on three values: alpha-fetoprotein (AFP), amniotic fluid estriol (E3) and the ratio of lecithin to sphingomyelin (L/S). Pregnant women can check whether their indicators are within the normal range through these tests. If it is normal, don't worry, but if it is not within the normal range, it will attract attention. Let's look at the specific values.

In the normal range of reference items, the abnormal risk ratio of lecithin to sphingomyelin (L/S) L/S≥2 (fetal lung mature) L/S≤ 1.9, and the fetal lung is immature, so newborns are prone to respiratory distress syndrome (RDS). Alpha-fetoprotein 20-48μg/ml is higher than the normal value 10 times, and the neural tube is open. Estriol (E3) in amniotic fluid is ≥100μ g/ml <100μ g/ml, which indicates that the fetal prognosis is poor. For example, if the fetus is anencephaly, with 2 1- trisomy, hypothyroidism and maternal-fetal blood group incompatibility, then E3 in amniotic fluid is very low. Amniocentesis results

Amniocentesis results

The results of amniocentesis usually come out 2-3 weeks after operation, but it depends on the hospital's schedule. Because the cells extracted by amniocentesis must be cultured to divide into enough numbers, this process usually takes about 7- 14 days. In order to alleviate the anxiety of expectant mothers, some hospitals also use interphase direct fluorescence in situ hybridization, and the results of chromosome abnormality can be obtained in 2-3 days.

What is the result of amniocentesis?

The analysis sheet of amniocentesis results will contain the data of alpha-fetoprotein (AFP). The AFP value in normal fetal amniotic fluid reached its peak at 12- 14 weeks of pregnancy, with an average value of 40μg/ml, and then began to decrease, which was almost undetectable at full-term pregnancy. If AFP in amniotic fluid is higher than 40μg/ml, it means that the fetus is probably anencephaly or spina bifida. There may be many other malformations, such as congenital nephropathy, esophageal or intestinal atresia, umbilical defect, cystic hydroma, sacrococcygeal teratoma, Rh blood group incompatibility, congenital idiocy, congenital gonadal hypoplasia and so on.

Estriol (E3) in amniotic fluid can accurately reflect the functional status of fetal placental unit, and can estimate the prognosis of abnormal fetus. The E3 value of normal fetal amniotic fluid is greater than 65438 000μ g/ml. If the E3 value on the analysis sheet is less than 100μg/ml, it indicates that the fetal prognosis is poor.

Is the result of amniocentesis accurate?

Amniocentesis has been used for prenatal diagnosis for more than 30 years, and its accuracy and safety have been recognized by the medical community. The accuracy of amniocentesis in detecting fetal chromosomal abnormalities is as high as 98%. However, any interventional examination has certain risks, and amniocentesis is no exception, but the risk is very low.

Amniocentesis to see men and women

The sex identification of the fetus can be determined by the chromosome in amniotic fluid, or by the secretion contained in amniotic fluid. However, the hospital will not tell the expectant mother the sex of the fetus, and the test report only has the diagnosis result of "no abnormality found", and there will be no identification of the sex of the fetus. In addition, amniocentesis is an invasive examination and the risk of abortion is 0.5%. Although the risk is not high, it is best not to take this risk for expectant mothers who do not need amniocentesis.

Countermeasures of amniocentesis

When doing amniocentesis, if there is fetal distress and maternal-fetal blood type incompatibility, amniocentesis should be done:

1, fetal distress

Treatment should be based on etiology, gestational age, fetal maturity and severity of distress. Details are as follows:

(1) Expectant mothers who can have regular prenatal check-ups estimate that the fetus is in good condition. Expectant mothers should take more lateral position to rest, strive to improve placental blood supply and prolong gestational age.

(2) The situation is difficult to improve, and it is close to full-term pregnancy. It is estimated that expectant mothers with a high probability of fetal survival after delivery can consider cesarean section.

(3) The farther away from full-term pregnancy, the less likely the fetus is to survive after delivery, so conservative treatment should be carried out as far as possible to prolong the number of weeks of pregnancy.

2. The blood types of mother and baby are incompatible.

If it is diagnosed as blood group incompatibility between mother and baby, it is necessary to prepare for perinatal detection and rescue after birth.

Amniocentesis cost

Amniocentesis, also called amniocentesis, is one of the prenatal examination items. It obtains information about fetal health and development by extracting amniotic fluid samples from pregnant women.

The cost of amniocentesis varies, depending on the level of the hospital and the city. Take Guangdong Maternal and Child Health Hospital as an example, the cost of amniocentesis is 2800 yuan. Cities in different regions have different prices:

The cost of amniocentesis in Beijing is about 2000 yuan, including cell extraction, incubation, karyotype analysis and necessary pathological examination.

The cost of amniocentesis in Nanjing is about 1300- 1400 yuan.

The cost of amniocentesis in Shanghai is about 800- 1000 yuan.

Noninvasive dna or amniocentesis?

Both noninvasive dna and amniocentesis can detect malformations, so what is the difference between noninvasive dna and amniocentesis?

Amniocentesis and non-invasive DNA are both used to detect Down syndrome. Amniocentesis is a diagnostic technique for fetal chromosome examination, which can find the number and obvious structural abnormalities of fetal chromosomes, while noninvasive DNA detection is a high-precision screening technique. However, the information of fetal chromosomes is limited. Amniocentesis can detect 46 chromosomes at a time, and structural abnormalities larger than 10m can also be detected. Noninvasive DNA can only be used for chromosome examination of trisomy 2 1, 18 and 13, so the result of amniocentesis is more accurate.

Amniocentesis is an invasive technique, which uses a fine needle to pierce the amniotic cavity through the abdomen of a pregnant woman under the real-time monitoring of ultrasonic waves, extracts an appropriate amount of amniotic fluid, collects fetal cells in amniotic fluid, and conducts special treatment after two weeks of culture to obtain fetal chromosomes for karyotype analysis.