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One move to America, one surprise pregnancy and a lot of fun later.

Tuesday, March 23, 2010

A Nuchal test and some Terracotta Warriors

Well I will start with the baby bit at the risk of boring everyone. If you are not interested just scroll down to the second part of blog. I am conscious of going on and on about baby stuff, like I am the only woman to ever have a baby in the world. It is just a large part of life for me at the moment that it is difficult to blog without making some mention. So, please bear with me until normal service is resumed.

Nuchal Test

Well I am a geriatric mum to be as I am the grand old age of 39. This puts me more at risk of having a baby with a genetic issue like Spinal Bifida or, the main one, Downs Syndrome. Spinal bifida is tested by taking blood from a finger prick and sending off to the lab. This was taken at my 10 week check up so I was just waiting for the results.

There are various ways of testing for Downs Syndrome. The first, and newest, is the Chorionic Villus Sampling (CVS) which is usually performed between the 10 and 12 week mark.
Who needs to take the test, and why?

CVS is used to get an early diagnosis of genetic and/or chromosomal abnormalities such as Down syndrome. It's offered when there's an increased risk of such defects, and when expectant parents want early test results instead of waiting to have an amniocentesis (which tests for many of the same abnormalities but is given only in the second trimester). You may be offered CVS if you will be 35 or older on your due date, have had a prior child with chromosomal or genetic abnormalities, or have a history of such problems in your family. If you feel strongly that you would rather have the option of terminating a pregnancy before the end of your first trimester, you should ask your doctor about this test as an alternative to amniocentesis. Be aware, however, that the CVS test carries a slightly higher risk of test-related miscarriage than amnio -- perhaps 1 in 100 for CVS as opposed to less than 1 in 200 for amnio. (Some medical sources say this risk could be as high as 3.5 or 4 in 100, but, to date, no controlled studies have been completed.) Also, you should be aware that CVS cannot test for neural tube defects.
What's involved?
Chorionic villus sampling begins with an ultrasound exam, which is needed to confirm the age of the fetus and the position of the placenta. Then, using the ultrasound image as a guide, the practitioner removes a tiny piece of the chorionic villi, the fingerlike projections of tissue that attach the placenta to the wall of the uterus. This can be done in one of two ways. (1) In a transcervical CVS, the practitioner inserts a narrow tube through the vaginal canal and into the cervix, using gentle suction to extract a bit of the needed tissue. (2) In a transabdominal CVS, a long, narrow needle is inserted through the abdomen and into the uterus to extract the tissue. The type of CVS your practitioner chooses to perform will depend on your individual anatomy and the position of the placenta. The villi sample (which shares the same genetic makeup as the baby) is sent to a lab, where it is grown in a culture, then checked for defects.
The test lasts about a half an hour, but the extraction process should only take a few minutes. It may be painless, or it may pinch or hurt briefly. Afterward, you should take it easy: plan to take the rest of the day off of work, arrange for a ride home, and relax. You may experience mild cramping and slight spotting. Any prolonged bleeding or cramping should be immediately reported to your healthcare provider.
When are test results available, and how are they interpreted?
Results are normally available within 7 to 14 days. CVS test results are more than 99 percent accurate in diagnosing many genetic and chromosomal abnormalities. If you receive "normal" results, your baby has an excellent chance of being healthy -- but be aware that the test doesn't rule out every possible problem. If your test results indicate an abnormality, you will meet with your practitioner and a genetic specialist to discuss your options, which may include further tests.

A very interesting test but it is still so new that there are a number of undocumented concerns about it. The first is that most practitioners are not yet experts and have not carried out the test regularly yet. One book I read said only to do it if it is done by one of the few experts available and definitely not to just let your normal practitioner do it. The other concern is that it has been thought in some cases (although unofficially) to cause missing limbs or appendages in the baby once born.

For these reasons and after discussion with other people, we decided against this test. The main reason being the very high risk of miscarriage.

The next type of test is at the 12 week ultra screen and is known as Nuchal Testing.

The nuchal translucency screening test is among the newest of the many first-trimester screening tests now being offered to pregnant women. The nuchal translucency (NT) screening test — basically a specialized ultrasound — lets you know if you're at an increased risk for having a baby with a chromosomal problem such as Down syndrome. Unlike amniocentesis or chorionic villus sampling (CVS), however, the nuchal translucency test cannot give you a definitive answer as to whether your baby has a genetic abnormality, but rather it gives the statistical likelihood of one. With that information in hand, you and your practitioner can then decide if further (more invasive, but conclusive) testing, such as amnio or CVS, is necessary.

What exactly does it measure? The test focuses on a small, clear space in the tissue at the back of your growing baby's neck called the nuchal fold. Experts have found that this spot tends to accumulate fluid and, as a result, expand in size in babies who have genetic abnormalities like Down syndrome (caused by an extra copy of chromosome 21, one of the 23 pairs of chromosomes that contain our genetic code), trisomy 18 (an extra copy of chromosome 18), and trisomy 13 (an extra number 13 chromosome).

Nuchal translucency screening — which must be performed between 11 to 14 weeks of pregnancy (after that, the tissue gets so thick that it is no longer translucent, rendering the test inconclusive) — is done with a highly sensitive ultrasound machine (but like a regular sonogram, is considered safe). A sonographer will first measure your baby from crown to rump, to confirm his or her gestational age, before zooming in on the nuchal fold and measuring its thickness on the screen. That value, plus the mother's age and the baby's gestational age, will be entered into a formula that calculates the probability of a chromosomal abnormality.

Because NT results by themselves have an accuracy rate of just 70 to 75 percent (meaning that the test misses 25 to 30 percent of babies with Down syndrome), your practitioner might offer what's referred to as a combined or integrated screening, in which the NT ultrasound results are combined with one or two blood tests that measure and compare your levels of two maternal pregnancy hormones, beta-hCG and PAPP-A. By combining these blood tests with NT, the accuracy of detection rates for Down syndrome rises dramatically to between 83 and 92 percent.

One drawback to the NT screening, and even the combined screening, is the risk of false negatives and false positives — not to mention the emotional hoops of worry and waiting that you'll have to jump through. But if you're on the fence about amnio, NT screening may help you determine whether you need it.

So we went ahead with this test as the risk to the pregnancy was zero anyway.

It was amazing to see the pictures of the baby again and how much it has developed in the 2 weeks since my first scan. It was also visibly moving in my uterus. It started off lying on its back and then flipped right over to be face down – which was a problem for getting the measurements. The sonographer made me shake my hips from side to side to try and get it to flip back and it eventually did. I was completely overwhelmed by seeing what was growing inside me and the fact that it was moving around.

Here are the pictures:

Before I took the test my risk of having a Downs baby was 1 in 102 because of my age. My Doctor phoned with the results after 24 hours and the results were good in that my risk had reduced to 1 in 2021, which is about the same as someone under 23 – therefore, my age is not a significant factor. I am also negative for Spinal bifida from my blood results which is good as well.
So the decision now has to be made as to whether we then follow this up with an Amniocentesis.
This is a much more conclusive test but also has a high risk (1 in 200 or 1 in 300 dependent on which book you read) of miscarriage.

How is amniocentesis performed?
An ultrasound is used as a guide to determine a safe location for the needle to enter the amniotic sac so the fluid may be safely removed. A sample of amniotic fluid is collected through the needle. The procedure takes about 45 minutes, although the collection of fluid takes less than five minutes. The amniotic fluid, which contains cells shed by the fetus, is sent to the laboratory for analysis. Results can take anywhere from a few days to a couple weeks to be returned.
When is amniocentesis performed?
Amniocentesis is usually performed between 14 and 20 weeks. Some medical facilities may perform amniocentesis as early as 11 weeks.
Amniocentesis can be used later in the third trimester for a few reasons. Your healthcare provider may recommend the procedure if your membranes have ruptured prematurely to assess for uterine infections. Amniocentesis may also help determine the severity of fetal anemia in babies with Rh disease and assist your physician determine whether the fetus requires lifesaving blood transfusions.
Amniocentesis is sometimes done to assess lung maturity. If so, this is done shortly before delivery.
What does the amniocentesis test look for?
Amniocentesis detects chromosome abnormalities, neural tube defects and genetic disorders. Down syndrome or Trisomy 21 is the most common chromosome abnormality. Genetic disorders include disorders like cystic fibrosis. The most common neural tube defect is spina bifida.
Amniocentesis is occasionally used late in pregnancy to assess whether the baby's lungs are mature enough for the baby to breathe on his own.
Amniocentesis also provides access to DNA for paternity testing prior to delivery. DNA is collected from the potential father and is compared to DNA obtained from the baby during amniocentesis. The results are accurate (99%) for determining paternity.
What do amniocentesis results mean?
Amniocentesis is a diagnostic test that detects chromosome abnormalities, neural tube defects and genetic disorders with high levels of accuracy (98-99%). Although the probabilities of identification are high, this test does not measure the severity of these birth defects. Alpha-fetoprotein levels and advanced level ultrasounds may assist in assessing the severity.
What are the risks and side effects to the mother or baby?
Although amniocentesis is considered to be a safe procedure, it is recognized as an invasive diagnostic test that does pose potential risks. According to the Mayo Clinic, it is performed approximately 200,000 times a year.
Miscarriage is the primary risk related to amniocentesis. The risk of miscarriage ranges from 1 in 400 to 1 in 200. In facilities where amniocentesis is performed regularly, the rates are closer to 1 in 400. Miscarriages can occur because of infection in the uterus, the water breaks or labor is induced prematurely

Now the decision has been very difficult as I have had to weigh up the risk of miscarrying a healthy fetus from the amnio or worrying about the risk of having a Downs baby.

I won’t go into my decision process as I don’t really want to open up a debate about handicapped children, abortions, adoption or any of the other subjects that comes up in these decision processes – I would support anyone in any of their decisions no matter what my beliefs are.
Anyway as my risk is so low we have decided not to have the amnio and see what happens. So now I guess I just have to sit back and let my body cook the little bun in my oven.
I have a doctors appointment every month and will get my next set of scans at the end of April at which time we should be able to see the sex of the baby (if we choose) if it is sitting in the right position. I want to know the sex just because I can. I said to Jarlath I wish you couldn’t actually tell and then I would be surprised but because you can I need to know – if that makes sense.

Terracotta Warriors
The Terracotta Army (simplified Chinese: 兵马俑; traditional Chinese: 兵馬俑; pinyin: bīngmǎ yǒng; literally "soldier and horse funerary statues") is the Terra Cotta Warriors and Horses of Qin Shi Huang the First Emperor of China. The terracotta figures, dating from 210 BC, were discovered in 1974 by some local farmers near Xi'an, Shaanxi province, China near the Mausoleum of the First Qin Emperor. (Chinese: 秦始皇陵; pinyin: Qín Shǐhuáng di). The figures vary in height (183–195 cm - 6 ft–6 ft 5in), according to their role, the tallest being the generals. The figures include warriors, chariots, horses, officials, acrobats, strongmen, and musicians. Current estimates are that in the three pits containing the Terracotta Army there were over 8,000 soldiers, 130 chariots with 520 horses and 150 cavalry horses, the majority of which are still buried in the pits.[1] Many archeologists believe that there are many pits still waiting to be discovered.

So, the National Geographic museum in Washington had an exhibition of them which we were very keen to see. I booked tickets for myself, Jar, Dawn, Simon and Vicky for an afternoon out and then the plan was to go out for drinks and dinner afterwards. This was all booked before I started to feel ill and before I knew I was pregnant.

I drove us all downtown and we started by having a coffee as we arrive a bit earlier than our entry time and also because Jar and I wanted to tell Simon and Dawn about the pregnancy. They had been in Canada working at the winter Olympics for all of February so we had not seen them yet to tell them. Jar handed Dawn the envelope with the scans and it was so sweet because she just burst into tears and was so thrilled for us. Simon was thrilled as well but didn’t show it quite as emotionally as Dawn.

We then went into the Terracotta warrior exhibition. I felt really warm and a bit faint so had to sit down a lot and just wait for every else. What we saw was interesting but the exhibition was just far too small. It was like we saw the introduction and were then expecting to go into the main exhibit but that was all they had. Not worth the money and it only lasted just over an hour and not the whole afternoon as planned. All a bit of an anti-climax for us which we all agreed on.
We all then headed to Georgetown for a bite of lunch and then just home. So from what was supposed to be a full day and night out we were all home by tea time. Not a problem as Simon and Dawn had lots to do after just getting back from Canada, I was knackered as usual and Vicky was tired from work as well.

So my recommendation is not to bother going to see the Terracotta warriors exhibition if it comes to a museum near you.
Well that is all for this week. Hope everyone is well. Xx

1 comment:

  1. Good stuff. Thank you so so much for sharing your knowledge with the world through the Internet. Wonderful blog and post you got here
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