I found a reference table that was published in JAMA in 1983. I am not sure if the figures have been revised since then, but here they are:
Mother age - frequency of DS fetus/non-DS fetus at 16 weeks - frequency of live births with DS/non-DS
35years - 1/250 - 1/75
37years - 1/150 - 1/225
40 years - 1/75 - 1/100
41 years - 1/60 - 1/85
42 years - 1/45 - 1/65
43 years - 1/35 - 1/50
44 years - 1/30 - 1/40
45 years plus - 1/20 - 1/25
1st column =maternal age (i think at birth)
2nd Column = frequency of DS fetus/non-DS fetus at 16 weeks
3rd Column = frequency of live births with DS/non-DS
The first figure is based at 16 weeks of gestation (time of amnio). The difference between the two figures is due to the increased spontaneous abortion with Down Syndrome pregnancies.
Last edited by HotI; September 12th, 2008 at 11:05 PM.
: clarifying columns
Hi,
I had my first bub at 40. I had a m/c at 38 and a troublefree pg at 40. Many people have a miscarriage and yes the stats do go up with age (i think they are around 35 to 40% at 40 ) but try not to think about it as you still have a great chance of having a healthy baby. I have lots of friends that have had babies at 40.
Kate has given you the stats for Down Syndrome which is what the nuchal fold test is for. It is a screening test so not a definitive answer. Depending on the results of the screening tests you could choose to go on to have the CVS or amnio which are definitive tests for DS and some other genetic abnomalities. It is a difficult thing to make a decision about as you really are only theorising on what you would do, until you get a result. I agree a statement like "i would never terminate my pregnancy" is not helpful as no-one really knows what they would do until faced with the situation. all birth defects (including DS) can vary in their severity so stats are not really that useful. for example a 43 year old friend of mine had a baby with a cleft palate. It was very minor and she had 2 operations and lots of followup and support and now at 2 has no ill effects. That would be included in stats but it is nothing that anyone could not deal with.
I will give you my experience. At 40, I was determined to have the amnio and ensure everything was OK. (I have an intellectually disabled brother and was sure I could not handle something similar) So I had the amnio and everything was OK but I did not put any really thought into what I would do if everything was not OK. I was a bit naive about it all.
I have been trying to get pg again since and have a few times but miscarried. the second time around I would be different. we have tried for 5 years to have a baby. there is a fantastic doctor at our ultrasound place that I have 100% faith in. I would have the nuchal fold test and the associated blood tests and if he said they indicated no increased risk for my age then I would not take the risk of the amnio causing a miscarriage (i had a very close friend have an unexplained miscarriage 2 weeks after an amnio). I would not choose to terminate the pregnancy just on amnio result as I have tried for a baby for 5 years and have no chance of having another. DH has a diferent opinion but we will come to a decision if we need to. My opinions have changed due to my experience.
Likewise you are your DH will have your own experiences that will influence your decision and are the only ones that can make your decision in your circumstances and you are doing exactly the right thing doing your research. Hope your pregnancy goes well.
Last edited by anney; September 13th, 2008 at 09:22 AM.
The stats are there based on age alone however when you have your 12w scan and blood test they combine these results for your own personal risk. An example is that for my age I have a risk of 1:150 however after my scan and the blood test my personal risk was 1:1800, this meant that based on my age alone I would have been recommended for an amnio (I think if less than 1:300 they recommend) however based on my personal risk there was no recommendation for further tests.
I think you and your DH need to decide what you want to do if you need an amnio or CVS and what you will do based on results from that. However at this stage I don't think you can decide that you will or will not have the amnio ro CVS until you get the results from your 12w scan & bloods.
If you are pretty certain you will go ahead with a CVS or amnio, to get a definitive answer, do you want to go through with the NT scan and blood tests?
Your risk figure based on age is roughly 1 in 100 (or 1 in 75 by amnio). If the result from NT scan gave you a risk of 1 in 150, would you still want a CVS/amnio? What is the result was 1 in 500 or 1 in 25? Would these results change your decision? Would they make you more anxious if the risk was greater?
It sounds like you guys want a definitive answer through CVS or amnio, and the NT scan might confuse the situation or add unneccessary anxiety where the diagnostic test can give you the answer you are looking for.
CVS or amnio are available to women over the age of 37 without having the NT scan.
Thank you for your information. You both have been really helpful. I will discuss with DH when he returns from his trip and come up with a plan. I really appreciate your support.
I had the nuchal fold test with my first child at 37 and again with my twins when I was 39. At that point I was only going to have more invasive tests if the U/S had given a high risk result. It didn't and all 3 babies were perfectly normal but sadly my twins were stillborn.
I had a M/C when I was 39 (after the loss of the twins) at 10 weeks Blighted ovuum). Fell pregnant again (still 39) and this time I decided to have an amnio. As I had already made up my mind, my OB said there was no need to have the nuchal scan at 12 weeks, so I didn't. I delivered a healthy baby girl. 9 months later (40) I was pregnant again and again had an amnio. Another healthy baby girl. Fell pregnant again when I was 43. Was going to have an amnio again but unfortunately my baby had died the day before the test due to a cord accident. Autopsy results showed him to be a perfectly normal little boy. My last pregnancy I again had an amnio and deliverd a healthy little boy and girl. I was 45 when they were born.
I had no problems with the amnio. I didn't find the procedure painful and I had no after effects. I just took it easy for a couple of days. I decided to opt for the amnio instead of the CVS due to the lower M/C risk. It is true that at the later stage, if something is wrong and you choose to terminate, labout will be induced. I was prepared for this. I had already delivered my beautiful twin baby girls into the world when they were no longer living. I knew if I could cope with that, I could cope with anything. But it is a personal choice.
I chose to have the invasive tests because I would have terminated if there had been a problem.
I hope this helps you with your decision. I also wish you a healthy and happy pregnancy.
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