What does prenatal diagnosis mean?
Prenatal diagnosis, also known as prenatal diagnosis or intrauterine fetal diagnosis, is a discipline in which cytogenetics, molecular genetics, biochemistry and clinical medical practice are closely integrated to obtain information about the embryo or fetus through interventional or non-invasive tests, with the aim of examining the fetus for serious diseases before birth, and diagnosing and treating these diseases.
Which pregnant women need prenatal diagnosis?
1.Advanced age (age 35 years or older)
2.Pregnant women with high risk of Down syndrome screening during pregnancy
3, Pregnant women in which both spouses are carriers of the same type of thalassemia
4.Ultrasound suggests fetal structural abnormalities
5, Pregnant women in which one of the spouses is a balanced ectopic carrier of chromosomes
6.There are known or suspected genetic diseases in the family
7.The fetus has a high risk of chromosomal abnormalities
8. Pregnant women suspected of having a fetus with a high risk of intrauterine infection
9. Pregnant women whose fetus is considered to be at risk for abnormalities based on clinical assessment by the obstetrician
10. Pregnant women with too much or too little amniotic fluid
What is interventional prenatal diagnosis?
Interventional prenatal diagnosis refers to the extraction of fetal related samples (chorionic villi, amniotic fluid, umbilical cord blood) through the abdomen of pregnant women under the guidance of ultrasound, followed by cell culture, molecular genetics or biochemical genetics examination for chromosomal diagnosis or genetic diagnosis.
What types and timing of interventional prenatal diagnosis?
The three main types include chorionic villus biopsy, amniocentesis, and umbilical vein puncture
1. Chorionic villus biopsy.
Generally performed at 11-14 weeks of gestation, it is performed under ultrasound guidance by transabdominal removal of placental villi tissue for laboratory examination, and is used to diagnose fetal chromosomal abnormalities and various hereditary monogenic diseases during early pregnancy.
2. Amniocentesis.
Generally performed at 18-24 weeks of gestation, it is an ultrasound-guided transabdominal extraction of amniotic fluid specimens for cell culture, karyotype and analysis of various hereditary monogenic diseases. Amniocentesis has been used in prenatal diagnosis for more than 30 years and has the highest accuracy and safety.
3. Umbilical vein puncture.
It is performed after 24 weeks of gestation and involves the ultrasound-guided transabdominal puncture of the umbilical vein to extract umbilical cord blood for fetal chromosomes, genetic monogenic diseases, teratogenic viruses, biochemical and routine blood tests, which can detect various fetal indicators in a more comprehensive manner.
Is the interventional prenatal diagnosis procedure painful?
The amniotic fluid and umbilical cord blood puncture needles are relatively thin, except for the chorionic villus needle, which is slightly larger.