Amniotic fluid biochemical examination

Amniocente biochemical examination is performed by taking pregnant women's amniotic fluid for biochemical examination to determine fetal maturity and predict fetal blood type and congenital abnormalities. Take the supine position after emptying the bladder. Abdominal disinfection should be extended to the periphery centering on the puncture point, and the radius should be no less than 10cm. Spread a sterile hole towel. The puncture site was partially anesthetized with 0.5% lidocaine infiltration. The 7th sterile waist pierced needle was inserted vertically. Through the two resistances of the abdominal wall and the uterine wall, when entering the amniotic cavity, there is a feeling of loss of tissue suddenly disappearing. When the needle core is pulled out, amniotic fluid is discharged, and about 20 ml of amniotic fluid is extracted with a syringe, and immediately sent for inspection as needed. Then, the puncture needle was removed, the pinhole was covered with a cotton ball and gauze, and the tape was fixed after pressing for 5 minutes. Basic Information Specialist classification: maternity check check classification: biochemical examination Applicable gender: whether women are fasting: fasting Tips: Inappropriate people: women with a pregnancy time of less than 12 weeks and more than 20 weeks. Normal value 1, fetal maturity determination Fetal lung maturation L/S ratio ≥ 2, PG positive in amniotic fluid, LB> 25 × 109 / L, EGF ≥ 4.5 μg / L in amniotic fluid; Fetal kidney mature creatinine ≥ 176.8 μmol / L, 132.5 ~ 175.9 μmol / L is the critical value; Fetal liver mature bilirubin △ OD450 < 0.02, 0.02 ~ 0.04 is the critical value; Fetal skin mature fat cell content > 20%, 10% ~ 20% is the critical value. 2, the prediction of fetal congenital anomalies AFP in amniotic fluid showed the highest value before 12 weeks of pregnancy, and began to decrease month by month from 21 to 26 weeks. The highest value was as high as (13286±6818) μg/L, and the lowest value was (180±158) μg/L. Clinical significance Abnormal results: 1, fetal maturity determination The ratio of lecithin to sphingomyelin in the fetal lung immature amniotic fluid (L/S)>1.5, the amniotic fluid phosphatidylglycerol (PG) was negative, the lamellar body in the amniotic fluid (LB)>25×109/L, the epidermis of amniotic fluid Growth factor (EGF)>4.5μg/L; Determination of creatinine in fetal kidney immature amniotic fluid and fetal kidney maturity <132.5μmol/L; Fetal liver immature amniotic fluid bilirubin △ OD450> 0.04; Fetal skin immature amniotic fluid fat cells <10%. 2 prediction of fetal congenital anomalies Fetal neural tube defects (NTDs) alpha-fetoprotein (AFP) in amniotic fluid is 3 to 30 times higher than normal; AFP increased in amniotic fluid in pregnant women with congenital nephrotic syndrome; AFP in amniotic fluid of Down syndrome pregnant women is lower than normal. Persons in need of examination: women who have given birth after the age of 35, have had abnormal fetuses, have repeated abortions, have married close relatives in the family, or have family history of congenital diseases such as hemophilia and leukemia. It is usually done for prenatal evaluation at 16-18 weeks of gestation. Precautions Before the test: empty the bladder. When checking: Actively cooperate with the doctor. Inspection process Take the supine position after emptying the bladder. Abdominal disinfection should be extended to the periphery centering on the puncture point, and the radius should be no less than 10cm. Spread a sterile hole towel. The puncture site was partially anesthetized with 0.5% lidocaine infiltration. The 7th sterile waist pierced needle was inserted vertically. Through the two resistances of the abdominal wall and the uterine wall, when entering the amniotic cavity, there is a feeling of loss of tissue suddenly disappearing. When the needle core is pulled out, amniotic fluid is discharged, and about 20 ml of amniotic fluid is extracted with a syringe, and immediately sent for inspection as needed. Then, the puncture needle was removed, the pinhole was covered with a cotton ball and gauze, and the tape was fixed after pressing for 5 minutes. Not suitable for the crowd Inappropriate population: women with a pregnancy time of less than 12 weeks and greater than 20 weeks. Adverse reactions and risks No related complications or hazards.

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