Transabdominal amniocentesis
Transabdominal amniocentesis is a prenatal diagnostic procedure that provides important information about the condition of the fetus. Doctors at the "Dobrobut" Medical Center use modern equipment and international guidelines to ensure that the examination is safe and effective.
During amniocentesis, a small amount of amniotic fluid is collected from the amniotic sac surrounding the fetus for analysis. This fluid contains fetal cells and various chemicals that can be analyzed to diagnose genetic disorders, fetal infections, and other pregnancy-related complications.
The procedure is typically performed between the 15th and 20th weeks of pregnancy but may be carried out later if necessary.
What is Checked During Amniocentesis
Based on DNA analysis of the fetal cells present in the amniotic fluid, the procedure helps to identify the following abnormalities:
- Genetic and chromosomal disorders: Down syndrome (trisomy 21), trisomy 18, and trisomy 13, as well as cystic fibrosis, sickle cell anemia, Tay-Sachs disease, and other hereditary conditions.
- Neural tube defects: the level of alpha-fetoprotein (AFP) is measured in the amniotic fluid; an increase may indicate neural tube defects, such as spina bifida.
- Fetal infections that may affect the fetus: toxoplasmosis, cytomegalovirus (CMV), and certain bacterial infections.
- Fetal lung maturity: especially important if preterm delivery is being considered; the levels of surfactant, such as lecithin and sphingomyelin, are assessed.
- Blood disorders and metabolic disorders, including thalassemia and hemophilia.
- Rh incompatibility: if the mother has Rh-negative blood and the fetus is Rh-positive, amniocentesis helps determine the degree of anemia and other complications in the fetus.
- Fetal sex: this may be important for diagnosing sex-linked genetic disorders.
- Polyhydramnios and oligohydramnios: these conditions are associated with excess or insufficient amniotic fluid and can be monitored through amniocentesis to assess their impact on fetal health.
The results of these tests can provide important information for managing the pregnancy, preparing for possible complications, or making decisions regarding potential medical interventions. It is important to discuss the specific risks and benefits of the procedure with the doctor.
Indications for amniocentesis may also include:
- Maternal age, as the risk and frequency of chromosomal abnormalities increase after age 35;
- Fetal pathologies detected during ultrasound;
- Family history that includes known cases of genetic disorders.
Contraindications to Transabdominal Amniocentesis
Certain conditions may increase risks or render transabdominal amniocentesis unadvisable. These include:
- Placenta previa: if the placenta covers the cervix, it increases the risk of bleeding.
- Acute infection: an infectious process in the cervix increases the risk of transmitting infection to the amniotic fluid.
- Insufficient amniotic fluid.
- Threatened miscarriage or premature labor.
- Serious maternal conditions that may increase the procedure's risks.
How Transabdominal Amniocentesis is Performed
The procedure involves several stages:
- Preparation: cleaning the injection site with an antiseptic solution.
- Ultrasound control: ultrasound is used to visualize the fetus, placenta, amniotic fluid and determine a safe site for needle insertion.
- Local anesthesia.
- Needle insertion: a thin hollow needle is carefully inserted through the abdominal wall into the uterus to take a small sample of amniotic fluid; ultrasound helps guide the needle throughout the process.
- Fluid collection: about 15-20 milliliters of amniotic fluid is collected into a syringe.
- Monitoring: the needle is removed, and the fetus is again examined using ultrasound to ensure there are no complications.
- Post-procedure care: the patient is advised to rest and avoid heavy physical exertion for a day or two; mild cramps may occur.
Results of Transabdominal Amniocentesis
The results of amniocentesis are usually available within 1-2 weeks. They can be vital for making decisions about managing pregnancy and delivery, especially when it concerns giving birth to a child with special needs, as well as for considering further medical interventions. The procedure is generally safe but carries slight risks for both the mother and fetus, so the pros and cons of the procedure should be discussed in each specific case.
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