What Does an Amniocentesis do for You?
Earlier this month, I went in for an amniocentesis aka amnio. We didn’t have one done when we were pregnant with lil man, but after two rounds of initial test results from an ultrasound and bloodwork, our OBGYN recommended it for lil lady. Our down syndrome risk was 1 out of 63. Lil man was only 1 out of 316 or so.
Even at 1 out of 63, it’s a 2% risk, but my OBGYN was concerned about our labor. Should the baby have down syndrome, it would be good to know in case we have complications during our labor. So, we elected to have the amnio done.
Besides down syndrome, what does the amnio do? The genetic counselor explained how they count every single chromosome the baby has. It determines how pairs they have of everything and whether there are any extra chromosomes anywhere. Basically, everyone has 23 pairs of chromosomes. Each pair is made of one chromosome from the mother and one from the father. When they’re looking at the chromosomes, they look at whether there’s a third chromosome hanging out next to each pair or if there’s a chromosome missing. The extra (or missing) chromosome means there’s an abnormality.
Here’s an image of our chromosomes called a karyotype.

The first 22 pairs are called autosomes. The 23rd pair is the sex pair which determines whether you have a boy or a girl. Two x’s = a girl and an x-y = boy.
Three of the most common abnormalities the initial amnio test look at are related to chromosome #21, 13 and 18.
- Trisomy 21 is the pair representing down syndrome. If that pair has a third chromosome then the child has down syndrome.
- Trisomies 13 (Patau syndrome) & 18 (Edwards syndrome) are more severe than down syndrome, but less common.
You can read more about these abnormalities and others on the March of Dimes website.
My genetic counselor said our initial results from the amnio would take 24-48 hours and would tell me whether the baby has down syndrome and trisomies 13 and 18. After two weeks, they’ll have a more thorough test result with an evaluation of all 23 pairs of chromosomes.
The amnio took about 10/15 minutes for me. The document and the ultrasound tech were very efficient, thorough and careful. The initial pinch of the needle feels like a needle from a blood test. After that, it can feel uncomfortable because of the pressure you feel in your abs and back. I was very glad when the amnio was over, but more relieved when they called with my initial results 30 some hours later.
Lil lady is negative for down, patau and edwards syndromes. Whew! Next week, we’ll find out about everything else. We are hoping everything else will be normal also.
So, what does the amnio do for you?
- Help your OBGYN determine how to handle your labor process if any complications occur.
- It can tell you if your baby has any abnormalities or not.
- If your baby does have abnormalities, it gives you time to prepare on handling the abnormality. Ie. child care programs, finding therapists/experts, learning about living with the genetic abnormality.
I feel number three is so important for parents. People are always talking about being prepared to have a baby, but it’s even more important to be prepared on how to handle the new lifestyle you’ll have if your child has a generic abnormality. It doesn’t mean they can’t have a healthy and happy life. It just means you’ll need to learn how to provide a better life for them should they be different from other children.
If you’d like to read more about genetic abnormalities, here are some resources:
March of Dimes also provides a comprehensive list of support groups on their website.