Your family / personal medical history or perhaps an ultrasound result may suggest to your doctor that you have a slightly greater chance of giving birth to an infant with a birth defect. Therefore your doctor may suggest that you undergo an amniocentesis, a test used to detect some foetal abnormalities.
What Is An Amniocentesis?
An amniocentesis (or amnio for short) is a test in which a small sample of liquor (from your baby's water) is taken from around the developing baby. A needle is passed through the abdomen, the wall of the uterus and into the liquor surrounding the baby without touching the baby or the placenta. Approximately 15mls of fluid is taken, this amount being small compared with the total amount of fluid present (at least 150mls) at the time of the test at 16 weeks.
Who Is Offered One?
- Women of 37 years and over at the projected time of birth
- Women who have already had a child with a problem such as Down’s Syndrome or Spina Bifida
Occasionally amniocentesis is done for other reasons. These include parents who are known to have a chromosomal abnormality or who are known to be at risk of having a baby with one of a number of rare abnormalities of their metabolism.
Why Are Women Over The Age Of 37 Offered An Amnio?
As the age of the mother increases the chances of her having a baby with a chromosomal abnormality also increases. The most common chromosome abnormality is Downs Syndrome. Between 37 and 40 years of age the chance of having a baby with an abnormality is approximately 1 in 100. Beyond the age of 40 years this chance increases even further. The incidence of Spina Bifida does not seem to be correlated with age.
When Is Amnio Performed?
An amniocentesis is usually performed from 14 weeks gestation.
What Are The Potential Complications?
There is a risk of miscarriage following this test, which is quoted at approximately 1 in 200 tests performed.
What Will Happen On The Day?
It is important that the mother’s bladder is full; this lifts the uterus up out of the pelvis making it easier to see the baby with ultrasound. The ultrasound scan is performed prior to the amniocentesis so that the pregnancy and the placenta can be checked and to determine whether there is a singleton or twin pregnancy. The ultrasound scan is quite painless and merely involves spreading a little warm gel over the lower abdomen and then moving an ultrasound probe gently over the skin surface.
After the ultrasound scan has been performed, the abdomen is cleaned and the needle is inserted into the uterus. The needle is watched all the time on the ultrasound screen. It then only takes about one minute to draw up 15-20mls of fluid into a syringe. After removing the needle and again checking the baby, the mother is able to get dressed and go home.
Almost without exception, patients experience far less discomfort from the test than they had expected. Any discomfort felt is usually similar to that felt for a simple blood test. It is recommended that for the rest of the day things are taken quietly, but after this to return to a usual routine.
Could There Be Any Problems Afterwards?
It is very rare to have any problems at all after the test. Occasionally there may be some mild discomfort due to a little bruising under the skin. If there is any loss of blood or water from the vagina or any pain after the amniocentesis you should consult your obstetrician.
What Tests Are Performed On The Fluid Taken?
An estimate of the amount of a particular protein (alpha feto-protein). There are usually large amounts of this protein present in the fluid if a baby has a defect called Spina Bifida.
The second test is carried out on the cells which are present in the fluid. The chromosomes of these can be examined and in this way it is possible to detect whether the baby has Downs Syndrome or any other less common chromosome problems. The sex of the baby is also determined.
How Long Will The Test Results Take?
The results of the Spina Bifida test are usually available after one week. Your doctor would not normally inform you of this result unless there was a problem. However the ultrasound examination would detect babies with Spina Bifida.
The chromosome test for Downs Syndrome takes from 10 to 21 days because the cells are required to grow in a laboratory for a period of days. The laboratory will send the results directly to your doctor. It will be the doctor looking after you and your pregnancy who will tell you the results of the amniocentesis.
Finally, it is important to realise that while a combination of amniocentesis (with a 99.9% accuracy) and a thorough 18-20 week ultrasound goes a long way to ensuring the baby is normal, it does not guarantee that every possible abnormality has been excluded.
Is It Worth The Risk?
The decision to have an amniocentesis is a very personal and difficult one to make. If you’ve had an amniocentesis before, BellyBelly would like to hear from you. What would your advice be to others in the same position? Email us your comments on this topic, and we will post them here for others to read, anonymously if you so wish.
Sammie had a CVS (Chorionic villus sampling – very similar to amniocentesis) and lost her baby. May be distressing for some readers. She says…
After [my loss] happened, I did a lot of research on [amnio/Chorionic villus sampling] and was completely HORRIFIED to find out the truth. They say that the chance of miscarriage from an amniocentesis or Chorionic villus sampling is 1 in a hundred. The question here is really WHAT they classify as a “miscarriage due to cvs” really is. What it means is that – you miscarry (start bleeding and baby’s heart rate stops) there and then on the table as the procedure is going on. THAT is 1 in a hundred chance they talk about.
But losing the baby within 2 weeks of the procedure, due to loss of fluid because of the holes they poke in you (me) or loss of cardiac activity due to the stress of the procedure – those numbers ARE NOT COUNTED in the stats. Can you believe it??? Because those rates are more like 1 in 20! However, because they cant with 100% certainty attribute the death to the procedure because you are not lying on the table, they do not count them in the stats!
What they also do not tell you is that the soft marker tests ARE DESIGNED TO GIVE FALSE POSITIVES. And that is from the horses mouth. My specialist told me as I was lying on the table not to worry to much about the T13, T12 and T21 rate they gave me (which was 1 in 2 for T21, 1 in 18 for T12 and 1 in 28 for T13 – yes. Very, very high) because it was specially designed to give false positives so that affected babies do not slip through the cracks. SAY WHAT???
My little precious was an IVF baby that I went to hell and back to conceive. I was actually pregnant with triplets but lost the identical twins every early on, around 5 weeks. I told them repeatedly that no way in hell would I terminate if they found anything wrong. Was not going to happen. They told me that there would possibly be things they could do to help the baby in-utero if there was a problem (and they were sure there was). So I had less than 24 hours to decide and I was so scared for my baby I went ahead with it.
They could not get a good angle to get the placenta because of its position, and the position of the baby, so they had to go in from 3 different angles. I was in such agony, the pain was unbearable. Anyway, they got what they wanted and it was over. PHEW.
I got up and sat on a chair and felt a strange twinge. Normal, they said. Don’t worry, just go home and rest. I got up and walked out to the front desk. All of a sudden I felt something warm running down my legs. The specialist was standing right there and I said “Oh my god, what is happening? Is it blood?” They ushered me through to a back room and I checked. No, it was just water. Thank goodness I thought! No blood, thats the main thing right?!
My specialist looked concerned and told me to go straight home and lie down. He was putting me on bed rest for a week. I had lost at least a litre of fluid. He told me not to panic, that the fluid replenishes its self every 4 hours. He would call me that night to see how I was going. I had another slight gush on the way home and that was it until 10 clock that night. I panicked and called my OB. He said NOT to go to the hospital, to just lie still and not move at all unless I absolutely had to go to (i.e. toilet only every 5 hours). I had one more loss of not much fluid and stayed on bed rest for another 2 weeks.
After that it was safe to move and I went back in for a check up to make sure the fluid levels were ok. Well, the fluid was fine but our darling was gone. I later found out that the doctor who performed the CVS would have known straight away that I was going to lose him because you cannot lose as much fluid as I did at that stage of the pregnancy and have the baby survive. He probably would have died within 4 hours of the first loss.
If I was cynical, I would say that they doctor did not make me lie down immediately in his surgery after the initial gush and stay there for 4 hours so he could scan me to check on the baby and fluid levels because the death would then it would be counted against his stats and also against the stats of his clinic…
You know the worst part? All the results came back and our wee man was perfect. 100% perfect. No chromosomal abnormalities, and a completely healthy and normal little baby. We were lucky enough to be able to get his remains and have him cremated so he is still with us. It is a very, very small consolation however.
I am currently going through my final ever IVF cycle. I just cannot put myself through any more. This will be egg harvesting (or fresh cycle as its known in IVF terms) number 8. If I am fortunate enough to get pregnant again, I will NEVER, EVER have a CVS or an amniocentesis. Ever. And I have made it my life’s mission to tell every pregnant woman I come across the TRUTH about the CVS and amnio stats.
CVS and amnio’s are big money in the private sector. I understand that a lot of people are willing to terminate and want to know within the legal limit for a medical termination but everything they test for can usually be seen at a 20 week scan regardless. Or during a later amnio when there is more fluid to take and its safer (around 20 weeks). I did not know, and was not told any of that. I was rushed in and rushed out. And paid a huge price for it. In all honesty, I will never forgive myself for my ignorance. I was in such a panic with these DREADFUL numbers that were telling me my beloved baby was riddled with birth defects. I should have not let them rush me. I should have not panicked. Sigh.
I think that if having my nightmare put on BellyBelly will help even one lady to really think about having the procedure done, then it will make me feel like it wasn’t all for nothing.
Lucinda had an amniocentesis and says…
“I was offered an amnio as there were some concerns surrounding my babies development. I opted to have one to know what I was facing. I found the procedure extremely stressful but quite painless. My husband held me hand and watched the whole time, I kept my eyes closed. I experienced mild cramping for a few hours afterwards but no bleeding. The results of the amnio came back showing no problems however the doctors advised us that meant that our daughter didn’t have any of the conditions they can test for with an amnio. 5 weeks after she was born she was diagnosed with a rare disability that could not be tested for using an amniocentesis. I guess I just want to educate women out there that an amnio cannot rule everything out. Looking back I wish I had known that as I doubt I would have had one.”
Jennifer had an amniocentesis and says…
“I had an amnio during my first pregnancy. Our baby was in the high risk of having Downs Syndome. An amnio was offered or we could have just continued on and found out at birth. We had to know. The test was the scariest thing I’ve gone through. It was relatively painless but very uncomfortable (physically), but emotionally, it was very painful for both of us. We had a long wait for a normal result. We look back now and regret making the decision to have the test. We look at our daughter and realise the risk we took. I guess we were naive as it was our first baby.”
Linda had an amniocentesis and says…
“I was offered an amnio at age 29 due to having antibodies similar to rhesus factor although mine are anti-I and anti-c, both attack the unborn baby in the same way as the rhesus does. My husband was positive for both the antigens and so we were offered the amnio to check the DNA make up of our son so they could determine his blood typing.
It was the hardest decision of my life, we had tried for this baby and I was so very scared of losing him to either the amnio or the antibodies. Trying to stop myself shaking from crying so hard was difficult. We decided to go ahead and have the test as if it showed our son to be negative it would mean a stress free pregnancy compared to a highly stressed and highly invasive pregnancy.
The procedure itself hurt quite a bit for me, but the emotional pain was worse. As it turned out, our son ended up being positive for both antigens so I ended up back at the same hospital every 3 weeks for the remainder of my pregnancy to monitor him through special ultrasound.
I would do it again if necessary, just so I knew what to expect from the pregnancy. That may seem selfish, but an antibody (or ISO) pregnancy is extremely stressful and to avoid that stress would be worth it.”
Cathy had an amniocentesis and says…
“We were booked for an amnio for our first child. However, the ultrasound before the procedure found that our child’s heart had stopped beating. I was almost 15 weeks at that point and had to wait another week before a scheduled D&C (dilation and curette). Before finding this problem, we had both decided to terminate if there was a problem. But since going through our first experience we are both unsure if we would terminate if given the choice (loosing a child is traumatic enough when the choice is taken from you, let alone making the choice yourself). In saying that, we again decided to have an amnio for our second child. I couldn’t go through the pregnancy not knowing. Neither of us knew what we would do if a problem was discovered. Thankfully we didn’t have to do anything (perfect 2 year old girl!). Tonight we are scheduled for an amnio for our third pregnancy (I am 14 weeks today). Again, we have no idea what we will do with a negative result. But I need to know what I am facing (good or bad).”
‘anonymous’ had an amniocentesis and says…
“My husband and I decided to have the amnio done after speaking to our doctor about the risks of down syndrome after the age of 40 (my age). I had read about false positives from the other less conclusive tests and didn’t take them as age gets thrown into the equation and we wanted a definite result. The only time I felt hesitant was after the 12 week scan when I saw our baby – however, I felt reassured at the thought of not personally knowing anyone who has miscarried after an amnio and that the research is dated on the miscarriage rates – rather than 1 in 200, it’s now more like 1 in 1,600 (I had it done in New York).
The process itself was easy. I wasn’t nervous, and I think that’s important. I closed my eyes and breathed through my nose. My husband looked at the screen and said he saw the needle go in by the baby’s head and she turned away. This is what I thought may be a problem as at the 12 week scan she was incredibly active. The doctor talked through everything he was doing, the needle going in felt less than plucking a hair, drawing out the liquid I felt a tiny sensation. Afterwards I had to sit for 20 mins or so and watch out for cramping. I felt nothing. The doctor said I could have a glass of red wine afterwards if cramping occurred which i was looking forward to, but as I didn’t cramp I forewent it! I took the whole week off work as I have an active job (personal trainer), even though I felt fine. Two weeks later found out everything was ok, but that last week is hell as you try to prepare yourself for the worse. I don’t know what to advise about the waiting time, as you are not only waiting for the results you have miscarriage at the back of your mind also. Music and a positive husband helped a bit.”