Babies Tale

Amniocentesis consists of taking a sample of amniotic fluid in the sac surrounding the baby and analyzing it. Amniotic fluid contains some of the baby’s cells, which can be cultured to reveal any chromosomal abnormalities. Amniocentesis can also be used to detect neural-tube defects, because there will be a very high level of AFP in the amniotic fluid in that case. This is much more accurate than the AFP blood test.

Amniocentesis is usually offered to women 35 or older, although the policy may change in the future. Age 35 was chosen originally because at this point it was believed that the risk of potential chromosomal problems with the baby was about the same as the risk of miscarrying the baby as a result of the amniocentesis test. However, amniocentesis is even safer now, so the mother’s age at which the test is recommended is being reconsidered upward.

The risk of miscarriage attached to amniocentesis is small.

Studies used to quote a rate of about 0.5%, but today it is closer to 0.3%. Some doctors dispute whether there is a real risk at all.

However, for older mothers, especially those with a history of miscarriage or infertility and for whom a pregnancy is particularly precious, there is a real fear of inducing a miscarriage. This can make the decision to have an amniocentesis very difficult.

Cindy was unlucky and had a miscarriage a week after her amniocentesis at the age of 39. “I was devastated. I blamed myself. They had told me the risk but it seemed so small. I’d never heard of anyone actually losing a baby. They said it might not have been the amnio that it might have happened anyway. But [the amniocentesis] seemed to me to be the most likely reason, because there was nothing wrong with the baby. It was a girl, and I had wanted a girl. I felt I had gone against nature and been punished. It was a terrible, terrible time for me.

“I did get pregnant again a year later and I had a boy. I decided against an amnio and he is fine. Everything is fine, but now I’m 41 and I may not get pregnant again. If I do, now I don’t know whether to have an amnio or not. I keep thinking that if I hadn’t had one I could now have had two children and my family would be complete. On the other hand, perhaps I should just count myself lucky that I am now a mother and have a healthy child.”

An amniocentesis is usually carried out at about 16 weeks into the pregnancy. This is about the earliest time that sufficient amniotic fluid can be withdrawn for testing. Usually an ultrasound scan will also be done at this time, to help the doctor locate the fetus and to identify the best place from which to draw the fluid. You will be asked to have a full bladder for the ultrasound scan, and then asked to empty your bladder before the amniocentesis is performed.

You will change into an examination gown, and the area on the abdomen where the needle is inserted will be swabbed with antiseptic. The needle is usually inserted without local anesthetic. The doctor directs the needle into the amniotic fluid and takes a small amount of the pale-yellow fluid. When ultrasound is used as well, the danger of the needle hitting the baby or placenta is very small. Most women do not find the procedure painful. They describe a slight cramp or pressure in the womb as the needle passes through the uterine wall. Some women feel a little sore for a day or two afterwards. You are usually advised to take it easy because of the slight risk of miscarriage.

For some women, however, the test is not so straightforward:

“We went along [with it] at 16 or 17 weeks. My husband came and we were all keyed up. They did the scan first and said the baby was lying all spread-out and there were no big pockets of fluid to get the needle into, so it wasn’t worth trying. We had to go back the following week-the anticlimax was awful.”

“While pregnant with Josh at the age of 35, I did worry a lot that he might have disabilities. I was feeling very aware of my age. When I was pregnant with Douglas at 37 I said I wanted an amnio. I was told the risk of this causing a miscarriage was about the same as the risk of the baby having Down syndrome and that I should only consider the test if I was prepared to have an abortion.

“I felt I couldn’t handle having a child with disabilities and that it wouldn’t be fair to the two boys. I had baby-sat for a child with mental disabilities and I had no illusions about how difficult it was and how it had affected her brother. I would certainly have had a termination if anything had been wrong.

“They made light of the procedure, said I didn’t need someone with me, it wouldn’t take long and it wouldn’t hurt. I was I6 weeks pregnant. Allen drove me to the hospital and waited outside. I was not given an anesthetic. Ultrasound was used to locate the baby and the bag of fluid. An enormous-looking needle was stuck into my very tender belly and it was excruciatingly painful. I gripped the nurse’s hand and counted to 60; the nurse kept saying, ‘It doesn’t usually hurt.’ Then it was all over. I was shaking and very distressed. Allen had to help me into the car; there is no way I could have gotten home by myself. I started having contractions when I got home and these lasted for four hours, but I didn’t bleed. I thought, ‘Oh God, what have I done? I’m going to lose the baby.’ I had to stay in bed all day and took things easy the next day.

“Waiting was OK for the first three weeks. Then the results were late, more than four weeks, so I thought something had to be wrong. I started to get very depressed. Although they said they would only tell the mother the results, I couldn’t face calling myself and got Allen to phone from his office. They told him all was well and we were both thrilled, though my mother burst into tears when I told her it was another boy. The whole thing was horrible, but it was still better than another four months of worrying. Now I could look forward to the baby happily.”

Others find the process much easier than they had thought:

“It was simple. I felt nothing. My husband was there and he said, ‘Did you really not feel anything? They seemed to take a ton of fluid!’ Everyone was extremely helpful and reassuring. It was much, much easier than I had imagined it would be.”

Once the test is completed, the drawn fluid is analyzed. Cells in the fluid are cultured and grown over a couple of weeks. Then they are crushed and put under a microscope so the chromosomes can be examined. Very occasionally the test fails and has to be repeated two or three weeks further into the pregnancy:

“I had an amnio at 16 weeks after much thought and consultation. The first one didn’t take, and I had another at 20 weeks, by which time I had felt the baby moving. I couldn’t understand what was wrong with the first test. I was worried it meant something was wrong with the baby.”

The fluid is also tested for high levels of alpha-fe top rote in, which can indicate the presence of a neural-tube defect.

If you are the possible carrier of a genetic disease, tests can be carried out to identify up to almost 80 hereditary diseases. These tests are time-consuming and expensive, so they will only be done if your family has a history of an inherited illness that technicians can test for.

Waiting for the results can be the hardest part of the whole procedure. Usually women are told the results will take three weeks, though sometimes they are received sooner and rarely, later:

“They said the results would take three weeks but it only took two. They had tried to call but we were out, so they wrote us a very nice letter saying all was well.”

You are usually informed by letter or by telephone; you can telephone yourself if the results are overdue. You can also ask to know the sex of the baby if you want to, though some hospitals insist on talking this over with you first:

“We had asked to know the sex of the baby but they were reluctant to tell us. They said to go home and think about it, and asked probing questions about did we want a girl or boy. When they called to say the results were fine, they didn’t volunteer the information. We pressed for it and were told it was a girl. We didn’t really care about the sex, but we both had a slight preference for a girl. We were delighted and it was wonderful to know, which I hadn’t in my earlier pregnancies. In fact, knowing was one of the most important parts of the pregnancy.”

There is some evidence that people who desperately want either a son or daughter have problems adjusting to the baby if they know in advance that it is the “wrong” sex. In the heat of the birth itself, most parents are so pleased to know the baby is all right that they don’t think much about its sex. The baby is there to love and care for. Knowing this fact while pregnant, however, gives a parent time to brood over the as-yet unknown person and sometimes to reject the baby, making it more difficult to adjust when the baby arrives.

This is an individual matter of course and people have different attitudes about it:

“I wanted to know. I thought if it was there in my notes and other people knew, then of course I had the right to know.”

“I told them, ‘Don’t tell me!’ I didn’t want to know-it would have ruined everything, like unwrapping a present before your birthday.”

“If it’s a first baby, I think once you know you feel a little sad no matter what, because you want both - you can’t really decide which your preference is. So when they said it’s a girl, I felt sad in a way that it wasn’t a boy. But it wasn’t that I actually had wanted a boy.”

Most hospitals respect people’s wishes in the matter, but some provide limited counseling to help a couple decide if they want to know or not. Occasionally one partner wants to know the sex and the other doesn’t; this is hard to deal with. If one partner is told and hides it from the other, it puts considerable strain on a relationship at a time when a couple should be as close and open with one another as possible.

One Response to “Amniocentesis”

1. MARINA GASK Says:
   October 7th, 2008 at 8:42 am

   Hello
   I am a journalist commissioned by Mother & Baby magazine in the UK to write a balanced feature about the dangers of miscarrying following an Amnio or CVS Downs Screening test. I need a case study - a woman who miscarried following such a test - and wondered if you could put me in touch with your case study, Cindy in the feature above.

   Many thanks
   Marina Gask
   Freelance journalist

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