Many pregnant women and their families are particularly confused about how to choose prenatal screening or prenatal diagnosis, and even some obstetricians and gynecologists are unable to provide suitable prenatal screening or prenatal diagnosis options for pregnant women and their families.
I. Which pregnant women choose Down’s syndrome screening?
Pregnant women younger than 35 years old with no history of adverse pregnancy (spontaneous miscarriage, fetal abortion, stillbirth, stillbirth, neonatal death and birth of malformed children), no family history of genetic diseases and no abnormalities in this pregnancy in singleton pregnancies are recommended to choose to do Down’s syndrome screening.
Time of Down’s syndrome screening: divided into early pregnancy (9 weeks to 13+6 weeks) and middle pregnancy (15 weeks to 20+6 weeks)
Early pregnancy Down’s screening mainly screens for trisomy 21 (Down’s syndrome) and trisomy 18; mid-pregnancy Down’s screening can screen for trisomy 21, trisomy 18 and open neural tube defects (such as anencephaly, open spina bifida, meningeal bulge, spinal membrane bulge, etc.).
Second, which pregnant women need to do amniotic fluid examination?
Pregnant women who have one of the following conditions need to do amniotic fluid examination.
1, age ≥ 35 years old pregnant women;
2.Pregnant women who have had a history of chromosomal abnormalities;
3. Pregnant women in which one of the couple is a carrier of a balanced chromosome translocation or inversion;
4. Pregnant women who may be carriers of an X-linked genetic disorder;
5. Pregnant women whose spouses have a monogenic disease or have given birth to a child with a monogenic disease;
6. Pregnant women who have a history of unexplained spontaneous abortion, malformation, stillbirth or neonatal death;
7. Pregnant women with high risk of Down’s syndrome screening;
8. Pregnant women with ultrasound suggestive of fetal abnormalities during pregnancy.
However, pregnant women with contraindications to amniocentesis are advised not to have amniocentesis for the time being.
(1) Pre-operative infections that have not been cured or infections and suspected infections on the day of surgery;
(2) Central placenta praevia or placenta praevia or hypoplacenta with bleeding;
(3) Those who have not been cured of miscarriage first.
3. Which pregnant women are suitable for non-invasive fetal DNA testing?
Non-invasive fetal DNA testing is a more accurate means of prenatal screening, not diagnosis. Pregnant women with high risk of Down’s syndrome need further amniocentesis to confirm the diagnosis.
1. Non-invasive fetal DNA testing is recommended for pregnant women who miss the screening time and have no indication for amniotic fluid testing;
2. Pregnant women who have indications for amniocentesis and contraindications for amniocentesis are recommended to undergo non-invasive fetal DNA testing;
3. Non-invasive fetal DNA testing is recommended for pregnant women whose prenatal screening risk value is in the gray area;
However, some pregnant women are not suitable for non-invasive fetal DNA testing.
(1) Pregnant women whose gestational age is less than 3 months;
(2) Pregnant women with IVF assisted pregnancy;
(3) Pregnant women with twin or multiple pregnancies;
(4) Pregnant women with chromosomal abnormalities;
(5) Pregnant women with indications for amniocentesis and no contraindications to amniocentesis.