When is amniocentesis done

summary

Amniocentesis during pregnancy is particularly important, you can know in advance whether the baby is normal, a friend recently found himself pregnant, but do not know when to do Amniocentesis? Let's talk about it.

When is amniocentesis done

First of all, in prenatal diagnosis, the best time for amniocentesis is 16-20 weeks of gestation. At this time, the extraction of amniotic fluid will not affect women's normal pregnancy, because at this time, the fetus is small, and the amniotic fluid is relatively large. The fetus floats in the amniotic fluid, and there is a wide amniotic fluid band around it. When the amniotic fluid is extracted by needle puncture, it is not easy to stab the fetus.

Secondly, 20 ml of amniotic fluid is extracted, which only accounts for 1 / 20-1 / 12 of the total amniotic fluid. During this period, the proportion of viable cells in amniotic fluid is the largest, and the survival rate of cell culture is high. It can be used for section, staining, fetal chromosome karyotype analysis, chromosome genetic disease diagnosis and sex determination. It can also be used for genetic disease diagnosis and metabolic disease diagnosis by amniotic fluid cell DNA. Determination of alpha fetoprotein in amniotic fluid can also diagnose fetal open neural tube malformation.

Finally, before the amniotic fluid puncture, the pregnant woman can lie in bed and turn over five times continuously, so that the fetal cells in the amniotic fluid in the uterus can be suspended, which is convenient for the puncture to extract more fetal cells. Abdominal puncture points (amniotic fluid and no fetal limbs) were determined by B-ultrasound exploration, or puncture was performed under B-ultrasound monitoring. Use the puncture bag to disinfect the puncture point according to the aseptic requirements, lay the hole towel, puncture with the puncture needle, slowly extract 10-20 ml amniotic fluid, slowly inject the sterile centrifuge tube along the tube wall, and seal it with aseptic seal.

matters needing attention

Do not share the same room three days before amniocentesis, and take a bath the day before. If you have a cold or fever, you should inform the doctor before amniocentesis, and pay attention to rest for at least two hours after operation.