Comparing other 36 year old women's first trimester screening results

[Anonymous]

I've browsed through a couple old posts regarding the decision-making process that some of us go through when deciding whether or not to do an amniocentesis.

I'm 36 years old; will be 37 at expected delivery date, and am about 14 weeks pregnant. I just got the results back from the first trimester screening. I had these test done at the Maryland Perinatal Associates, where they did a nuchal translucency screen and a blood test that measured 2 different proteins produced by the pregnancy (PAPP-A and free beta hCG).

I got a result that said my risk of the baby having Down Syndrome is 1 in 767. I have no idea what sort of algorithm the genetic counselors or the labs used to determine my risk. They said everything looked perfectly normal in the NT and the blood work.

I know that a result of 1 in 767 is very good, but the results haven't seemed to make the amnio decision a whole lot easier....I've read several posts from women of a similar age who received risk factors something more like 1 in 3000. I know I shouldn't compare my results to others, but.....I still do wonder how the risk algorithm determines our risks and why it's those numbers can vary so much. Does anyone have a deeper understanding of this? Do other 36 year olds care to share their first trimester screening results?

Apparently I can do a "modified sequential screening" blood test which will further fine-tune those risk numbers.

[Anonymous]

It really is an intensely personal decision. I have to say that at the age of 40 my risks of Down's after the screening was much less than yours (don't remember exactly but it was less than 1/1000) - but, given my age, I opted to get the amnio anyway. I was rather surprised at how incredibly relieved I was after getting the amnio results back - didn't realize I was a concerned as I was (since I had such a good screen).

[Anonymous]

I'll share. I will be 36 when i deliver my first child next month.

My test results came back with a 1 in 470 chance of Down syndrome, which is about half of what is normal for our age, apparently. I probably would have gone without the amnio, but my 20-week ultrasound showed what's called an intracardial echogenic focus, or a bright spot on the heart. I did some reading of medical journals and studies on the web and concluded that up to 4% of babies that showed this abnormality at the 20-week ultrasound were born with Down Syndrome. The specialist I saw (because of "advanced maternal age") said that he estimated that this abnormality doubled my chances of having a Downs baby.

I asked him what he would do if it were him. He said, "would you do anything about the amnio results came back positive for Down?" I said, "yes, we'd probably have to terminate." (I'm a single working mom and the baby's father was facing potential deployment for much of her childhood - I didn't think a special needs child was something we could handle, given our situation.) He said, "I'd do the amnio. The miscarriage risk is probably 1/500, smaller than the estimated 1/235 chance of Downs."

We had the amnio and found that baby tested negative for everything they test for, with 99% certainty. The days immediately following the amnio were a little nerve-wracking, but the peace of mind following the results was probably worth the fear.

You have good odds. If you're comfortable with them, and ok with the slight possibility of genetic abnormality, forego the amnio. If you are someone for whom 99% certainty outweighs the very small potential miscarriage risk from the amnio, or if you would do something about the results, have the amnio. (note: it's expensive- cost me $2700 out of pocket - so see if your insurance covers it.)

Good luck!

[Anonymous]

I'm older than you (39 at the time of the test, 40 by the time I deliver) but can give you my experience. From random internet reading I was convinced that my numbers would come back worrisome simply because of my age, and having had an amnio for my first child 5 yrs ago I was fully expecting to have another. Instead, the final numbers put my risk at the equivalent of a 20yo - somewhere in the range of 1 in 1600 for Downs, 1 in 3100 for the other trisomies. I was a little unsure of how to proceed, and the genetic counselor suggested pushing up the 20w detailed u/s to 18w. The idea was that if there were any worrisome signs in that u/s, I would still have plenty of time to have an amnio and consider all my options well before 24w (even though our preference was to carry to term unless there was something truly catastrophic.) That u/s went well, and so no amnio. In various discussions on this board, it seemed like most of the moms did get an amnio just for peace of mind, and that was my strong initial preference as well. But in the end I feel very comfortable with my decision, and my ob told me that the frequency of amnio is declining a bit due to confidence in the NT results. For me, getting more detailed info at 18w via the ultrasound was a major confidence booster... if you're on the fence about an amnio, it may be something to consider since it still leaves you lots of time to pursue more testing if you want it.

[Anonymous]

OP here: thanks for your insights, everyone.

That was an interesting note re: the one poster for whom the amnio was not covered under insurance. I just checked with my insurance company and they're like "yes, if the doctor orders the amnio, it should be covered, but of course everything is still subject to medical review." That's a typical vague answer. It's interesting to me that, in this decision-making process, if there were a huge financial cost involved, that may sway me against doing the test. It's strange. Money shouldn't come into it but it could still be a major factor since we simply could not afford something like a $2700 test.

[Anonymous]

Here's my story. I was 36 when I got pregnant and a few days away from 37 when I delivered my healthy baby.

My NT test and blood work estimated my risk as 1 in 37. I freaked, cried, worried, etc. But then my very kind doctor said that another way of stating 1 in 37 is there's a 1% chance of Downs or heart defect (which can also cause a higher NT test). So I calmed down, and decided not to do the amnio. A 1% risk of something going wrong seemed pretty small to me, and I had trouble getting pregnant so I didn't want to do anything that had a risk of miscarriage. And DH and decided if we had a baby with Downs, we would not terminate. I did have follow up ultrasounds to make sure there wasn't a heart defect and those ultrasounds showed none of the secondary signs of Downs or any sign of a heart defect, so I stopped worrying.

[Anonymous]

Dear OP,

We had a higher than normal risk of Trisomy 13 and 18, but our risk for Trisomy 21 (Down Syndrome) was very low. I was 34 at the time, delivering at 35 and decided to do the CVS because it was still early enough in my pregnancy. The CVS didn't work, so I also then had to do an amnio which came back negative for any type of chromosomal abnormality.
We decided to do the additional testing for two reasons: the first reason was that we already have a child and didn't think it was fair to her to bring her into the traumatic situation a Trisomy 13 or 18 baby would cause, and the second reason was that we thought that Trisomy 13 and 18 were such horrible defects that we couldn't possibly carry out a pregnancy full-term.
Like a PP said, doing the amnio or not is such a personal decision that will have to be decided based on your unique beliefs, values and situation.
One thing I found out during our ordeal is that the rate of "false positives" or high probability for the pre-screening is very high. I found an Australian website called Essential baby that helped me through the most difficult times. Good luck to you in your decision!

[Anonymous]

You do have good results.

I am 35 and will be 36 at delivery. I was informed at 13w that my NT and bloodwork yielded a 1/1500 risk for the trisomies. (Interestingly, I was not provided with distinct probabilities for the different trisomies, as other posters seem to have been; I will have to ask my doctor about that at the next appt).

We chose not to do any further testing. If there are markers that raise serious concern evident at the 20w anatomy scan, I suppose we would consider (although not be automatically inclined to do) an amnio for informational purposes, i.e. to help educate and prepare ourselves for how to deal with a congenital defect.

Good luck with this intensely personal decision.

[Anonymous]

OP here: To the last poster - that's interesting that you got results for all the trisomies rolled into one number.
I got a number of 1 in 767 for Downs, while my number for trisomy 18 and 13 was about 1 in 7500.

I talked to the genetic counselor again today. She helped put things in perspective when I said
I was worried that other women in my age bracket were getting results that seemed "better"
because their numbers were like 1 in 1500 for Downs. She said that some people get
"better" numbers simply because their body chemistry is different; the difference
between getting a number of 1 in 767 and 1 in 1000 or 1 in 1500 is statistically insignificant.
She said my numbers were totally normal and there's no need to worry. That made me feel better.

Having all these tests and information available to us can be such a double-edged sword.