Amniotic fluid analysis is a procedure where the amniotic fluid is extracted under sonographic guidance via transabdominal puncture for diagnostic purposes. The best time for amniocentesis is 16-24 weeks of pregnancy.
Before performing amniocentesis, B-ultrasound should be performed to determine the position of the fetus and the condition of the fetus, so as not to accidentally injure the fetus.
After selecting the needle entry point, disinfect the skin, spread disinfectant towels, local anesthesia, and then the selected place is pierced vertically, passing through the abdominal wall and the uterine wall.
The doctor will draw 2ml of amniotic fluid with a 2ml syringe, and then draw 20ml of amniotic fluid with a 20ml empty needle. After aspiration of the amniotic fluid, remove the needle, cover with sterile gauze, and press for 2-3 minutes.
At this time, the pregnant woman has to rest in bed for 2 hours. When doing amniotic fluid puncture, you should also be very careful not to touch it when taking a shower.
What amniocentesis can detect
- Sonographic appearance of a fetal nuchal edema in the 12th to 14th week of pregnancy for Down’s Syndrome.
- Following pathological first-trimester combined screening (for cardiovascular system) or second-trimester screening (for amniocentesis) results
- Suspected toxoplasmosis
- Determination of bilirubin levels in cases of rhesus incompatibility
- Monitoring of electrolytes in suspected renal failure
- Estimation of lung maturity in imminent preterm delivery via lecithin-sphingomyelin ratio
- Determination of insulin levels in gestational diabetes
- Drainage of excess amniotic fluid in polyhydramnios or amniotic fluid replacement in oligohydramnios
How often does the amniotic fluid puncture produce results
After completing the amniocentesis check, the result is usually taken after 4 weeks. If the test result is positive, the examiner will be notified as soon as possible. Generally, if there is no notice, it means that it is normal.
Do not be nervous, relax, and do regular rechecks, pay attention to nutritional supplements, and your baby will be very healthy. However, the specific amniotic fluid puncture results are still based on the hospital’s regulations. The results of each hospital are different, generally around 3 weeks, 4 weeks ago.
Precautions for amniotic fluid puncture
Amniocentesis is an invasive test, so there are some risks:
- Amniocentesis may cause bleeding in pregnant women, hemorrhagic shock, amniotic fluid outflow, miscarriage, and the possibility of injury to the fetus.
- The puncture may have failed due to malformation of the uterus, placenta in the anterior wall, and too little amniotic fluid.
- If the pregnant woman has poor sanitary conditions after the operation, intrauterine infection may occur.
- If the pregnant woman has cardiovascular and cerebrovascular diseases, due to pain, tension, etc., it may cause cardiovascular and cerebrovascular accidents.
- Due to the influence of a variety of factors such as amniocentesis time, whether the specimen is mixed, and culture medium contamination, the culture of amniotic fluid cell exfoliated cells in vitro can cause failure of amniotic fluid culture.