Medical tests: Amniocentesis

Amniocentesis

What is amniocentesis

Amniocentesis is a diagnostic test that is performed during the pregnancy and in which a small amount of amniotic fluid is extracted in order to study possible fetal disorders.
Amniotic fluid surrounding the fetus and protects you. It is located within the amniotic sac, which is a bag that is in turn inside the uterine cavity. Amniotic fluid contains fetal cells and chemicals produced by the fetus that are that are studied after the completion of this test.
This liquid is obtained through a small puncture with a thin needle that is inserted through the abdominal wall and uterus. While the puncture is performed an ultrasound properly guide the direction of the needle to remove fluid from the right place.

When do an amniocentesis?

The main indications of the amniocentesis are as follows:
The study of malformations or genetic disease in the fetus, as for example Trisomy of chromosome 21 or Down's syndrome. Usually indicated when tests for screening of malformations that occur during pregnancy yield abnormal results. You can also indicate when any member of the couple is a carrier of a genetic defect or when there is a history of chromosomal alterations or fetal malformations, such as spina bifida, in previous pregnancies. It is usually done between weeks 15 and 18 of pregnancy.
Used to determine if a fetus lungs are mature enough as for can be born safely. This may be indicated if they are considering ending pregnancy before time for risk to the mother or the fetus. This type of amniocentesis is performed between 32 and 36 week. Before the 32nd week it is likely that the lungs of the fetus are still immature.
It serves to diagnose intrauterine infection.
Determine the sex of the fetus.
You can know the Rh factor of the baby and to assess the severity of anemia in the fetus in case of Rh incompatibility with the mother.
You can use as a treatment to reduce the amount of amniotic fluid in cases in which there is fluid too much (polyhydramnios).

Preparation for amniocentesis

These are the issues that you must consider when you undergo an amniocentesis test:
Duration: an amniocentesis usually lasts about 15-20 minutes, although most of the time is dedicated to ultrasound guiding the puncture, which lasts less than two minutes.
Entry: the test is done on an outpatient basis, and the patient can go home the same day after its completion.
Is necessary to be accompanied?: don't have to be accompanied by although it might help if it makes you feel more relaxed.
Drugs: don't need to take any medication prior to this test. You can take your usual medication. If you put the anticoagulant medication (such as heparin) you must warn it to your doctor.
Food: don't have to go on fasting. You either need to go with a full bladder, as it is done for the Gynecologic ultrasound, because the amniotic fluid itself already allows ultrasound to look good.
Clothing: can wear the clothes you want.
Documents: prior to amniocentesis physician will explain the test to you and will provide you with an information sheet (informed consent) which must be signed and which details the procedure and potential associated side effects. Please read this document carefully and ask the doctor questions as it considers necessary before fimarlo.
Contraindications: there are some pathologies of the mother as chronic (such as HIV or hepatitis C) infections, clotting problems or pregnancy complications that may contraindicate the realization of the test. Refer to your doctor all of their prior history.
Pregnancy and lactation: this test is carried out on pregnant women.
Other considerations: before the test, can take you a blood sample to determine the Rh factor in blood. If you are Rh negative can give a vaccine to prevent problems by Rh incompatibility between his blood and that of the fetus. Since the test has a small risk of complications, consult your doctor the possibility of performing alternative diagnostic tests or failure to perform the test if it will not change the attitude to pregnancy.

Procedure: how an amniocentesis

During amniocentesis the patient lies down on a table face up.
He gets a special gel in the abdomen that facilitates the realization of an ultrasound that will locate the amniotic fluid.
Apply an antiseptic substance in the puncture area.
You can put any anesthetic in the puncture area substance although not always done, because the needle is very thin and is hardly noticeable.
In the abdomen puncture guided by ultrasound is made and extracted a small amount of amniotic fluid with a syringe. The amount of fluid being removed depends on the reason for the test.
After removing the fluid, the needle is removed and gets a small dressing in the puncture area.

After amniocentesis

After the test, is recommended rest and avoid physical exertion such as lifting objects. Usually a next day already can be a normal life.
You may have some mild abdominal discomfort after amniocentesis. If after the test, you experience abdominal pains like cramping, leakage by the vagina, vaginal bleeding, fever or any discomfort that preoccupied him consult quickly a doctor.
The small amount of fluid removed is replaced naturally fast.

Complications or side effects of the amniocentesis

Amniocentesis is a very safe technique. You can see a slight pain at the point of puncture and some abdominal discomfort when the needle passes through the uterus.
The major complication of amniocentesis is the risk of miscarriage. If done during the second quarter, it is estimated that abortion occurs in 1 of every 300-500 amniocentesis.
Very rarely, if the fetus is moved during the test sufir can a prick while the needle is getting. Serious puncture the fetus are extremely rare.
It is also uncommon to happen leakage of amniotic fluid from the vagina, which usually resolve spontaneously.
If the mother is Rh negative and the fetus is RH-positive problems could be generated by the lack of compatibility Rh are prevented with the administration of a vaccine.
The risk of uterine infection is very low.
Possible transmission of infection from mother to the fetus such as HIV or hepatitis C. Therefore in case of chronic infections in the mother, amniocentesis is contraindicated.

Results of an amniocentesis

The results of the test genetic tend to be available in a week or two. The results of the amniocentesis performed to determine fetal maturity of the foetus are available within a few hours.
The results of the test studying genetic defects or malformations are reliable, though not at 100% and also not diagnosed all genetic diseases or possible malformations.
If an abnormality in the fetus is detected your doctor will help you decide on the future of the pregnancy in those difficult moments or the following care.

Article contributed for educational purposes