Ultrasound: What is a Level Two Ultrasound?
I'm 34 years old and my AFP results came back, indicating a 1 in 150 chance of Down syndrome. My doctor has given me a choice of having a level two ultrasound or an amniocentesis to further diagnose. What is a level two ultrasound, and how does it compare to an amniocentesis in diagnostic ability?Question:
Ultrasound is becoming better at visualizing the various markers of genetic abnormalities. It is not, however, 100 percent diagnostic. Amniocentesis, on the other hand, will give you the precise diagnosis of whether or not your baby has Down syndrome.
Some women prefer to have an obstetric ultrasound -- or level two ultrasound -- instead of an amniocentesis. Amniocentesis is invasive: It carries a small chance of fetal loss and complications.
All ultrasounds performed after 18 to 20 weeks should be level two ultrasounds. This means that gestational age and fetal growth measurements are noted, along with comments about the brain, heart, kidney and cord insertion, amniotic fluid volume, placental position and obvious maternal pelvic organ abnormalities.
If the triple screen, quad screen or AFP demonstrates a higher risk of Down syndrome, this should be noted on the ultrasound request. Then markers should be noted by the ultrasonographer or radiologist. Such indications of Down syndrome would be foreshortened thigh and upper arm bones, echogenic bowel, nuchal (or neck) thickening, kidney abnormalities, choroid plexus cysts and structural fetal abnormalities, such as a heart defect.
Level I, which is a more basic exam, would include information about fetal number, fetal presentation, documentation of fetal life, placental location, assessment of amniotic fluid volume, assessment of gestational age, survey of fetal anatomy for gross malformations and an evaluation for maternal pelvic masses.
The standard of care is to offer amniocentesis to all women who will be 35 when the baby is expected. I hope this helps you in your decision and I wish you the best.Answer: