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Archive-name: misc-kids/pregnancy/screening/AFP Posting-Frequency: monthly Last-Modified: January 8, 1995 ------------------------------------------------------------ Misc.kids Frequently Asked Questions AFP Screen and the Triple Screen ===================================================================== Collection temporarily maintained by Lynn Gazis-Sax (gazissax@netcom.com) while Dorothy is on maternity leave. Collection maintained by: Dorothy Neville (neville@cs.washington.edu) Last updated: 1/8/95 To contribute to this collection, please send e-mail to the address given above, and ask me to add your comments to the FAQ file on AFP Screen and the Triple Screen. Please try to be as concise as possible, as these FAQ files tend to be quite long as it is. And, unless otherwise requested, your name and e-mail address will remain in the file, so that interested readers may follow-up directly for more information/discussion. For a list of other FAQ topics, ftp to the pub/usenet/misc.kids directory of rtfm.mit.edu or tune in to misc.kids.info. ===== Copyright 1994, Dorothy Neville. Use and copying of this information are permitted as long as (1) no fees or compensation are charged for use, copies or access to this information, and (2) this copyright notice is included intact. ==== ===================================================================== [NOTE: this is information collected from many sources and while I have strived to be accurate and complete, I cannot guarantee that I have succeeded. This is not medical advice. For that, see your doctor or other health care provider.] SUMMARY: These screening tests are used to predict which pregnancies are at elevated risk of certain abnormalities. They do not give conclusive results; an abnormal result means that more testing is suggested. This can be very distressing. Especially distressing is that some caregivers and books do not make clear the inconclusive nature of the tests; women have been told that their baby definitely has a defect on the basis of this test. This is irresponsible medicine. Most women with abnormal results will have healthy normal babies. Below are some details about the tests and what they can and cannot do. The information is mostly taken from two brochures prepared by the Laboratory of Pathology of Seattle and the Swedish Hospital Medical Center. I have also added information from other sources. Every woman contemplating these tests should have access to accurate information in order to make an informed decision about whether or not to have the tests, and how to interpret the results. Unfortunately there are enough stories on misc.kids to show that this does not happen. Perhaps the following will be helpful to those contemplating having the screen, or people who have had the screen and have gotten disturbing results. INDEX: 1. What are the Screens? Neural tube defects: 2.a What is alpha-fetoprotein 2.b Why is age of the fetus important? 2.c What are the neural tube defects and their severity? 2.d What are my chances of having a baby with neural tube defects? 2.e What about folic acid? 2.f Will this test detect all cases of neural tube defects? Down's Syndrome 3.a What is Down's syndrome? 3.b Will this test detect all cases of Down's? General 4.a Will this test guarantee a normal baby? 4.b How are the results presented? 5.a What should I do if the values are abnormal? 5.b If the ultrasound is normal, does that guarantee a normal baby? 6.a What are the benefits of the test? 6.b What are the risks of the test? 6.c Should I have the screen? 7. What are some resources for more information? 8. Some stories from women who have had the tests. ---------------------------------------------------- 1. What are the screens? 1. This FAQ covers questions about two similar tests that are available for pregnant women. The first, AFP, is a measurement of alpha-fetoprotein. The second test is newer and combines the AFP test with measurements of two hormones, unconjugated estriol and human chorionic gonadotropin. It is often called the "triple screen". ----------------------------- Addition by Dr. Tim Reynolds: The triple test is a mis-nomer. The test combines AFP with a variety of different assays and no definite proof of which is best currently exists In fact they are all about the same so far as data available allows us to tell. Combinations available are. AFP + total HCG AFP + Free beta HCG (free beta is a subsection of the HCG molecule) AFP + total HCG + unconjugated estriol (uE3) AFP + free beta HCG + uE3 AFP + free beta HCG + uE3 + Free alpha HCG AFP + free beta HCG + uE3 + neutrophil alkaline phosphatase The detection rates reported for these different combinations all suggest Detection rate is about 60% and differences of 1-2% exist between different combinations: However the data available is not sufficient to determine which combination is better. Other evidence suggests that as the number of analytes used to estimate risk increases, the errors become multiplied and the result becomes less accurate. It is probably better therefore to use the simpler screening combinations (AFP + total or free beta HCG) and not bother with uE3, free alpha or any of the other markers. If you are told that you can have a 2-marker test or a 3-marker test if you pay more: opt for the 2-marker test. ----------------------------- Both tests use a blood sample from the mother at a specific time during pregnancy. The AFP can be done during weeks 16 to 18 LMP, the triple screen can be done from weeks 15 to 18 LMP. ----------------------------- Addition by Dr. Tim Reynolds: The test can be done using AFP + free beta from 11 weeks, but the diagnostic test has a very high rate of miscarriage (up to 5%) so it is best to wait until 14 weeks (at least). The accuracy of the test is affected by gestation dating: It is best to have an ultrasound scan before the screen to confirm your gestation dates. ----------------------------- An elevated level of AFP in the sample indicates an increased risk of neural tube defects in the fetus. A depressed level of AFP indicates an increased risk of Down's syndrome. The triple screen uses levels of all three substances to indicate increased risk of Down's. This is considered a more accurate screen for Down's. ----------------------------- Addition by Dr. Tim Reynolds: Down's syndrome is associated with decreased AFP and uE3, and increased HCG. A combination of low AFP and high HCG is particularly significant. The maths of calculating results is quite complex but also takes into account the maternal age. ----------------------------- Neither test can tell you if something is wrong with your baby. Only a diagnostic test (such as chorion villi sampling or amniocentesis) can tell definitively if something is wrong. The AFP and the triple screen help to identify pregnancies that are at increased risk. BEING AT INCREASED RISK DOES NOT AUTOMATICALLY MEAN YOUR BABY HAS A DEFECT! Most women who find themselves in the elevated risk category give birth to healthy, normal children. This fact is often missed when interpreting the results of this screen. ----------------------------- Addition by Dr. Tim Reynolds: In young women, the predictive value of a +ve Downs screen result is about 1%: i.e. only 1 in every 100 young women with a +ve result will be carrying a Down's fetus. In older women, the +ve pred. value is about 4%. ----------------------------- 2.a What is apha-fetoprotein? 2.a AFP is a protein produced by every fetus. The baby urinates it into the amniotic fluid, and it makes its way from there into the mothers blood for excretion. There is a normal range of AFP found in the mothers blood; this is determined by the age of the fetus. A baby with an open spinal defect often leaks larger quantities of AFP into the amniotic fluid, and in turn, into the mothers bloodstream. An elevated level of AFP *does NOT* diagnose a neural tube defect! Babies with such defects tend to produce more AFP, which gets into the mother's blood, but there are also other reasons for an elevated level. The most common reason for elevated AFP is that the age of the fetus was estimated incorrectly. Twin pregnancy would also tend to show elevated levels. ----------------------------- Addition by Dr. Tim Reynolds: This is a good reson why an ultrasound should be done first because it is not possible to do Down's screens on multiple pregnancies: An amnio is needed for confirmation of result and it is virtually impossible to be certain that trisomy cells found in a twin pregnancy come from a particular twin: This leads to the possibility of a selective abortion in which the wrong twin is aborted: Ergo, Down's screening in twin pregnancies is very inadvisable. ----------------------------- 2.b Why is the age of the fetus important? 2.b The normal ranges of AFP and the hormones of the triple screen will vary with the age of the fetus. So in order to determine if the values are in the normal range, one must have an accurate date. This can be problematic if date of conception or last menstrual period is not known. For women with cycles significantly longer or shorter than 28 days, or who don't have regular cycles at all, scheduling or interpreting the results of the screens will be difficult if not impossible without ultrasound to more accurately date the fetus. The first thing that many doctors do when a patient has an abnormal AFP or triple screen is request an ultrasound to recalculate the age of the fetus (and to rule out twins). Often the recalculated age is enough evidence to rule the screen result normal. ----------------------------- Addition by Dr. Tim Reynolds: Better to do scan first (this is standard practice in most centres in the UK). ----------------------------- 2.c. What are the neural tube defects and their severity? 2.c The two main defects are spina bifida (open spine) and anencephaly. The problems associated with spina bifida will vary with the size, location and nature of the opening in the spine. Problems range from mild backaches to severe mental retardation, paralysis, bowel and bladder control problems and leg deformities. Generally speaking, the AFP test is more likely to detect the more severe forms of spina bifida. Anencephaly is a failure of the brain and skull to fully develop. It is incompatible with life. 2.d What are my chances of having a baby with a neural tube defect? 2.d In the US, about 1,600 to 2,000 babies are born with spina bifida each year. About 800 are born with anencephaly. (from American Baby, jul 93) The cause(s) are unknown. Having one child with a neural tube defect does increase the probability of having another. Yet, over 95% of babies with neural tube defects are born to families in which there is no history of birth defects or pregnancy problems. 2.e What about Folic Acid? 2.e Folic acid (or folacin) is a vitamin found in green vegetables, legumes and other sources. An average diet is generally deficient in folic acid. Studies have shown that when women with known risk factors of having a baby with neural tube defects take folic acid supplements from before conception to about 8 weeks of pregnancy, they can reduce their risk for these defects. A more recent study claims that this is beneficial for all women, not just those with previous risk factors. For pregnant women or those trying to get pregnant, the recommended daily amount of folic acid is either 400 or 800 micrograms (.4 or .8 mgs) depending on what source you read. It is very unwise to take more than a 1000 micrograms (1 mg) a day, as folic acid at this level can mask other serious health problems. In fact, because of this caution, in some places folic acid is not sold over the counter as a stand alone supplement. This may be changing due to this new link to neural tube defects. I was able to find 800 mcg folic acid capsules over the counter in Washington state. Someone from Pennsylvania reports that it is not available there except by prescription. All prenatal vitamins ought to have at least 400 mcg. The FDA is also considering requiring fortification of grain products with folacin. While the benefit of taking folic acid on neural tube defects is limited to early in pregnancy, it is still an important nutrient for building red blood cells and is important throughout the entire pregnancy. Some doctors are beginning to consider it as important as iron supplementation. Talk to your dr for his or her recommendation. 2.f Will this test detect all cases of neural tube defects? 2.f No. The screening process will detect 80% of the cases of spina bifida and 90% of the cases of anencephaly. ----------------------------- Addition by Dr. Tim Reynolds: Hence the argument for a detailed ultrasound scan at 18 weeks (routine UK practice in most good centres is a dating scan either at booking (8-12 weeks), or when the Down's test is collected (16 weeks): PLUS, a detailed 'anomaly scan' at 18-20 weeks. ----------------------------- 3.a What is Down's syndrome? 3.a This chromosomal disorder is characterized by varying degrees of mental retardation and an increased risk of physical defects. It occurs in about one in six hundred births. The risk increases with the age of the mother, but women of any age can give birth to a baby with Down's. Until recently it was thought that a woman's age was the only indicator of Down's risk. Measuring the amount of AFP, or better, the triple screen, and using this information as well as age will give a more accurate estimate of the risk of delivering a baby with Down's. 3.b Will this test detect all cases of Down's? No. 25% of the cases of Down's will result in abnormal AFP, while 60% of the cases will register as an abnormal triple screen. ----------------------------- Addition by Dr. Tim Reynolds: Above line incomplete: The detection rate is dependant on maternal age: in young women (age 12-16), the average detection for a multi-marker test will be about 40-45% and for an AFP only test, about 20% (There is NO SANE REASON for testing for Down's using AFP only: this is completely superceeded by multimarker testing). In older women the detection rate for the Down's screen is much higher and can be up to 90-95% in women aged 45+. The 60% figure quoted in most women's magazines is the average detection rate for a normal population assuming all women are screened. If all women over 35 get an amnio and only younger women are screened, the apparent success of the screening test will look poorer: If only older women get screened, the apparent success rate will look better (Many of the differences in detection rates for different screening combinations can at least partially be explained by age distribution differences in the study populations). ----------------------------- 4.a Will this test guarantee a normal baby? No. Most defects are not detected by this or any other test. However a few rare defects may be detected in addition to neural tube defects and Down's. Some pregnancies which may be at increased risk for low birth weight and prematurity are occasionally identified, as are some twin pregnancies. Note that this identification does not come from the screen itself, but from follow-up testing. 4.b How are the results presented? The results may be presented in a number of ways. It is important to understand what your numbers mean. Ask your caregiver to explain. The triple screen might be given as a probability such as: "based on maternal age your risk of Down's is 1/390 --- when the levels of AFP, HCG and uE3 are also taken into account, your risk is 1/14000. Based on AFP levels, your risk of neural tube defects is 1/1400." Or the results might simply be positive/negative, or normal/abnormal. You will probably want to know exactly what that means. Ask. In fact, there is controversy as to what "abnormal" means. Try to find out what your lab considers abnormal. They are working from the more detailed probability information. I think that it is becoming more common for the results to be given as probabilities, which are more meaningful than a simple "positive/negative" which is impossible to interpret. Probabilities can still be kind of scary to interpret though. ----------------------------- Addition by Dr. Tim Reynolds: Probabilities can be very misleading and are often 'over-interpreted by obstetricians as a way of avoiding doing amniocenteses. The usual risk cut off in the UK is 1 in 300: Using this cut off about 1 in every 50 amnios will yeild an abnormality. Some obstetricians use 1 in 150 as a cut off. This halves the number of amnios they do. The rationale for using this cut off is that the risk of abortion due to amnio is about 1 in 150. Since in the 1 in 300 group you expect 1 in 50 amnios to give an abnormal result it is evident that their argument is specious. ----------------------------- 5.a What should I do if the values are abnormal? Your caregiver should recommend an ultrasound to get a more accurate dating and to rule out multiple fetuses. Over 90% of the time, abnormal AFP values are due to these or other benign factors. Then a second AFP test might be run. If that is also abnormal, a more sophisticated ultrasound and amniocentesis would be suggested. The diagnosis of neural tube defects usually requires a combination of AFP testing, ultrasound and amniocentesis. Diagnosing Down's requires amniocentesis, but an ultrasound can be suggestive (see next question). ----------------------------- Addition by Dr. Tim Reynolds: It is best to get amnio first as this prevents the anxiety! ----------------------------- Since time and worry can be an issue, perhaps you and your caregiver will decide to get the more sophisticated level 2 ultrasound on the basis of one abnormal test. This is something that you should discuss with your caregiver. 5.b If my ultrasound is normal, does that guarantee a normal baby? 5.b No. The ultrasound exam, however. will identify the majority of defects which cause a high AFP level. Factors such as the experience of the ultrasonographer, the weight of the mother, the position of the fetus and the quality of the equipment can affect its accuracy. In addition, there are no reliable ultrasound findings for Down's. However, Down's can be strongly suggested by an ultrasound because Down's babies often have a certain body/face type. From one woman: "There are, however, several characteristics that are common to Downs' babies that a skilled ultrasound technician can look for. My technician measured the femur (usually short in Downs' Syndrome babies), checked the number of blood vessels in the umbilical cord (Downs' babies sometimes have one fewer), checked the width of the forehead (usually wider for a Downs' baby), and checked the heart (apparently, Downs' babies are more likely to suffer from heart defects). A finding that none of these characteristics are present does not guarantee a healthy baby, but it may provide some reassurance, particularly in a case where the AFP reading is only borderline low." Here's some statistics about elevated AFP and normal ultrasounds: Physician-researchers at Boston's Brigham and Women's Hospital, after studying 87,584 pregnancies, reported that an elevated AFP [alpha-feto-protein] level in conjunction with a normal ultrasound scan implies a less than 0.1 percent chance that the baby will have one of the four most common birth defects. In light of the finding that amniocentesis itself carries a 0.5 to 1.5 percent chance of terminating a pregnancy (Robin J.R. Blatt, Prenatal Tests), the researchers have concluded that "many women may choose not to have an amniocentesis when informed that the risk of pregnancy loss is substantially greater than the likelihood of finding an anomaly". (New England Journal of Medicine 323, No. 9, Aug 30, 1990) 6.a What are the benefits of the test? It can help you make decisions about your pregnancy. If the results are abnormal, and follow-up diagnostic testing shows defects, some women may decide to terminate the pregnancy. For those who carry an affected baby to term, the information can help in managing the delivery and early care of the infant. This can improve the long and short term outlook for the child. Sometimes when the AFP level is high, but the baby is normal, it is a forewarning of later pregnancy complications such as prematurity or low birthweight. Knowledge of this risk may alter the management of your pregnancy. There is recent evidence that shows that babies born with spina bifida may benefit greatly from being delivered via cesarean section. So having a cesarean in addition to other early intervention could significantly change the outcome for such a child and his/her family. (the woman who told me this could not find the source for reference. Your doctor might have more information. I could not find anything on medline but I am a medline novice.) [It looks equivocal. There is no consensus on this, and it may end up being decided one way or the other--so the answer is, ask the doctor.] 6.b What are the risks of the test? An abnormal result may cause considerable worry and concern. Since most women with abnormal results will have healthy normal babies, you may decide that the test is not worth the possible anxiety. Some statistics: about 5% of women tested will have abnormal readings. About 90% of those will not have affected babies, but have abnormal values because the dates were calculated wrong, there are twins, or other reasons. So, for every 1000 women tested, about 50 will be told they have increased risk, and of the 50, about 45 or more will in fact have normal pregnancies. Some people feel that the high level of "false-positive" readings make the test not worth the risk. The tests are relatively cheap. However, follow-up diagnostic testing is not. These costs may be covered by insurance. The test itself has no risk to the baby. The only risk to the mom is pain from the blood draw. However, if the results are abnormal, you may wish to opt for an amnio to relieve your worries. Amnio does carry a small risk of miscarriage. The test will not identify all cases of neural tube defects or Down's. The problems for a baby with spina bifida range from the very minor to the very severe. Generally speaking, the test detects only the more severe problems. However, you may not be able to get exact details about the severity in any particular case. This could lead to months of anxiety. The AFP cannot be done until week 15 or 16, and takes about a week to get the results. Followup amnio means even more waiting, so if termination is decided, it will probably not happen until week 18 at the earliest. This can be very difficult emotionally, and more difficult physically than an early termination option with the CVS. ----------------------------- Addition by Dr. Tim Reynolds: Depending on the equipment your lab has, the result may be available within 24 hours. In my lab we are aiming for a 6 hour turnaround. ----------------------------- 6.c Should I have the screen? No one can answer that but you. Making a decision means learning as much as possible about the possible outcomes, and thinking about what you would do in each case. Then ask: Will the results of the test (positive or negative) change what you plan to do? If not, then there is no reason to have the test and risk the anxiety that an abnormal result would bring. I can tell you why I chose to take the test, and why my sister chose not to have the test. Now these are only two of many stories. And I had a reassuring result on the triple screen, (but no baby yet to confirm) and my sister has two healthy babies. Perhaps our answers would be different in hindsight if the situations were different. I am sure that many other women have different reasons for electing or not electing the test. I read everything I could about the test, including the two brochures my midwives gave me. My husband and I discussed what we might do in case of scary results. Given our personal views and our stages in life, we would be willing to opt for the amnio, and potentially termination if the results were very extreme. Extreme for us is probably something that is incompatible with life. And if results were bad but not extreme, we would find it helpful to know something in advance. We are planning a homebirth, so knowing that there were problems with the child in advance, we would change our minds and deliver in a hospital with a good neonatal unit. I also think that the extra months of research and gathering of support before birth would make it easier for me, my husband and our marriage to prepare for a handicapped child. I am not yet old enough, nor are there any familial factors, to be in a high risk category otherwise, so would not be doing genetic testing unless the screen indicated a potential problem. So we saw the test as useful information. Plus, the midwives have been very clear about the nature of the test, and assured me that a bad result should not be considered alarming. I trust that if we had gotten bad news, we would have been given timely and helpful information and referrals to specialists. I think that would help to alleviate the inevitable anxiety of any possible result. My sister and her husband have very different views. They would never consider termination for any reason. So an abnormal result could mean months of anxiety, since they would not consider the risks of the amnio to be worth it. Countering my reason about knowing in advance and being able to get some information and support before a baby with a defect is born, she would argue that since it cannot tell you *how* bad the defect might be, it is still not worth the worry. 7. Further Resources: If your caregiver does not provide detailed description of what the test is and is not, then you should complain. Everyone ought to get accurate information before electing a test with such an emotional component. Here are some books recommended by various people. Sheila Kitsinger: _Your Baby, Your Way_ as a good general pregnancy guide that has good section on AFP testing. ------------------ "I found a book in the local library on prenatal tests (again, we have since moved so I can't give you a reference; however the title was something like "Prenatal Testing: What You Need to Know") that actually listed averages and ranges for the AFP levels at different points in the pregnancy & gave some information on how those ranges corresponded to risk of abnormalities." ------------------- "I suggest that you refer readers to a terrific book on the psychological effect on women of prenatal testing, _The Tentative Pregnancy_ by Barbara Rothman. (This would go in your section 7, I guess). The book was written before AFP became common, and deals with amnio for women 35 and over, but is really very helpful. The running theme in the book is how women planning amnio protect themselves by not conceptualizing the fetus as 'their baby' -- even not feeling it kick until after the amnio results are in. Hence the title. She talked with women with a wide range of viewpoints, from "my sister-in-law has Down's and I would have amnio no matter what my age", to "I could never abort or risk hurting my baby, no matter what." The book also covers borderline diagnoses (chromosomal abnormalities that may or may not lead to problems), knowing the baby's sex (she strongly recommends _against_ this), the roles of husbands, doctors, and genetic counselors in the decision-making process, and how to minimize the negative psychological effects throughout a tested pregnancy (e.g. don't fall into the trap of thinking negative amnio == perfect baby). Given my experience with an AFP Down's scare, I believe that the AFP extends this tentative pregnancy most painfully to younger women in a way that might be called 'the on-and-off' pregnancy. In the typical AFP scare for a woman younger than 35, you are tentative in the first trimester because of the risk of miscarriage, then you get un-tentative and the fetus becomes a baby to you. If your AFP then indicates a high risk of Down's, overnight you have to distance yourself from the pregnancy again in case you have a bad amnio result. By this time your baby is kicking, of course. Then finally your amnio is fine, and you can go back to feeling really pregnant again. This roller-coaster is a nightmare! Rothman does point out that AFP can save older women from the trauma of amnio if their results are normal." ----------------------- 8. Some stories from women on misc.kids who have had the screen. -------------------------- I had a borderline low (whatever that means!) AFP result when I was pregnant for the third time. I had miscarried just 2 months before conceiving, so I was considered at somewhat higher risk for problems (according to one of the 5 doctors in the group practice I went to; the others did not feel that conceiving so soon after miscarriage constituted a measurable risk). I was told that the risk of Downs was about 1 in 270, and the doctors recommended amniocentisis. I did not want to have amnio, primarily because of the recent miscarriage. I requested a second AFP test, and they gave it to me, although they said that their policy was to only offer a second test when the initial result was high. This is because the AFP level normally increases during this period & a somewhat higher level with re-testing would be expected. However, since the results are interpreted in light of how far along the pregnancy is, I reasoned that a re-test might provide meaningful information. The re-test was normal (risk of Down's reclculated at about 1 in 780, which was consistent with my age at the time). I also had an ultrasound at this point and the technician checked for several characteristics that are common to Downs' Syndrome babies. She found none, and after that I was able to relax & not worry about the AFP test. I gave birth to a healthy baby boy. Carol Fischer (cfischer@sbu.edu) Mom to Katie (2/12/89) & Mark (8/3/92) ----------------------------- Personal anecdote: since ultrasound and AFP are non-invasive, we decided to take the AFP. We would not have done so had the only folllow-up possibility been amnio, since the relative risks were not worth it to us for neural tube defects. If an ultrasound showed a neural problem, we might then consider amnio. For Down's, we would not take amnio as this doesn't indicate severity, we were told, merely incidence. We therefore would not terminate a Down's child, so considering relative risks, amnio wasn't worth it (I was 28, so low risk).) Gail Anderson <ga@aiai.edinburgh.ac.uk> ----------------------------- We went through an AFP scare during my first pregnancy (a low result on the triple screening test, indicating a slightly increased chance of Down's Syndrome). I had let them do the blood test without really thinking about the consequences (and without realizing that I could have refused it); we had just assumed that the results would be normal, just as we assumed (also erroneously) that everything else would be fine with the pregnancy too. After we got the results back, we spent several days agonizing over what to do but then finally decided against the amnio because we weren't willing to take even the small risk of anything happening to our baby. Sadly, I lost the baby a few weeks later due to my incompetent cervix; she was very premature and couldn't survive on her own, but she was perfectly healthy and did *not* have Down's. For my second pregnancy, we decided right away to refuse the AFP test. Based on our first experience, we now know that there is a high risk of a false positive result (in other words, a good chance that the test will indicate a possible problem even when the baby is perfectly healthy). We knew that we would once again refuse to do an amnio for the same reasons as last time (and felt even more strongly about that once we found out that I was carrying twins, since a twin amnio is even more complicated and risky than a single baby amnio). To us, it just wasn't worth the risk of having another abnormal AFP result hanging over our heads for half the pregnancy, even though we knew that probably the results would come back normal and thus be reassuring to us. Thomas and Alison were born August 7, 1993, and were both perfect and healthy. We feel strongly that every pregnant woman should be given this kind of information in order to make an educated decision for herself -- not just a decision of what to do if the AFP test comes back abnormal, but first a decision of whether to even take the AFP test! Amy McNulty amy_mcnulty@vos.stratus.com -------------------------------------- "I am four and a half months pregnant with my first child and had a terrible experience with this test a couple of weeks ago. My doctor phoned me at 7 pm one night and said that my AFP test results had come back VERY abnormal and that I had a one in 17 chance that I was carrying a Down's Syndrome baby. After repeatedly telling me that he didn't do abortions (unsolicited info), I was scheduled for an emergency ultrasound, which fortunately appeared fine. More importantly, my doctor then told me that based on the ultrasound dating, my AFP test results were recalculated and came back normal (I had been instructed to take the AFP too early--at less than 15 weeks, and the lab was told I was at 16 weeks at test time). I am angry because this doctor miscalculated my due date, which is what caused the error (I have been very certain about my dates all along) and at his alarmist attitude. I'm also angry because several of the books I was frantically consulting during the sleepless nights after his phone call had misleading info. I am now consulting a new doctor and feel better about my own situation, but my confidence has been shaken and I'm sure there are a lot of other people who have been through similar traumas." --------------------------------------- At about this time last year, I had my AFP test. It was a little high. (we had taken a cvs test, so we knew that down's was not a problem. wouldn't you know it would come back high -- spinal and nerve problems are definitely not covered by the cvs test.) I was told by my doctor that when the test registers near the border line in either direction, that the likelihood of a problem is smaller. Their policy was to give another test, and if the results were duplicated, look for alternative means of determining whether a problem exists. In my case, the results came back high again. They still reassured me that the likelihood of a problem was small. I then had a Level II ultrasound which indicated that there was a 99.5 chance that nothing was wrong. I was satisfied with that. I now have a healthy baby girl. My sister also had AFP test oddities. Hers, like yours was low. She had opted not to have an amnio since she was not planning to do anything if there was a problem, and was extremely worried about miscarrying. My mother then spent the next several months worrying about her grandchild-to-be. My sister, after the initial shock, was more fatalistic about the whole thing. She also has a very healthy, normal little girl. (I began to wonder when I got my own weird results if weird AFP results ran in families!) My point? I think that the AFP test has a lot of false results. Try not to worry too much. I tried to get as much information as I could at the time, (most of the details of which I have forgotten) but remember being really surprised that the test was as unreliable (and popular!) as it was. I remember all that I went through while waiting to find out if every thing was okay. At first I was really sorry that I had taken the test especially since I was going to proceed regardless of the test results. Later, I realized it might be better for my baby if I knew there were problems in advance. That way if the baby required any special treatment, or having a c-section or whatever, I was prepared and so were the doctors. I know what a difficult time this is. But you're right - take it a day at a time and try not to worry too much -- I think the odds are in your favor. Good luck. suez@stdavids.picker.com (Susan Zemel) ----------------------------- I'm 31 years old and expecting my second child. I took the AFP when I was pregnant with my first and the results were normal. About two weeks after I took it this time, I got a call from the advice nurse with my OB practice, and she indicated that I had a 1/120 chance of having a baby with Down's Syndrome, based on the test. I was in such shock that I didn't really know what questions to ask. She told us that my test was most likely indicating a false positive, but that the only way to be certain was to have an amniocentesis. She said could set up an appt. with a genetics counselor and asked if I was interested in having the amnio. I numbly replied "yes". At this point, I didn't think to ask for a re-test, or ask for more detailed information. When my husband called her back the day before our appt. with the geneticist to ask questions, she was quite nonchalant! Very disturbing! We saw a genetics counselor, who explained the risks of Down's Syndrome for the average woman my age and my risk as indicated by the test. I was immediately suspicious when she explained that the dates used in testing were based on LMP. I felt that my "real" dates differed from LMP dates by about 4 days (LMP indicated I was farther along than I was). The geneticist re-ran the calculations, just to see what the risk would have been had I been not quite as far along in the pregnancy (by 1/2 week). The risk in that case was only 1/280, and they consider anything better than 1/200 normal. So, we had a Level II ultrasound, which confirmed the LMP dates to within a week. The doctor (a perinatologist (sp?), not one of the OB's in my practice) said she couldn't change the date used to calculate my risk of Down's since the ultrasound confirmed the date _within the accuracy of the ultrasound_. Luckily, there were no indications of Down's from the ultrasound. My husband felt very reassured at that point that nothing was wrong, but I really needed to know for sure. So, we also opted for the amnio. Amazingly, we found out the results in only a week (rather than the 2-3 weeks the advice nurse had originally told us). Our baby girl is not a Down's baby! If/when we have another baby, we plan NOT to take the AFP. The anguish we went through was horrible and we were really lucky not to have to wait so long for the results of the amnio. The AFP is so imprecise that 1/2 week meant all the difference in terms of dating the pregnancy. I'm not surprised that it commonly gives false positives. I'd much rather have a Level II ultrasound on the next go-round and skip the AFP. Laura Weaver laweaver@ralvm29.vnet.ibm.com ----------------------------------------- Here's another horror story with a happy ending. I wasn't sure whether I wanted to have the AFP test. I had read the FAQ and saw all the people on the net who had had false alarms with it, so I talked to my Dr. about it for a long time. She recommended it, but said I didn't have to have it. I asked if the triple screen was available, figuring that even if one of the numbers came back alarmin, that the other 2 numbers might provide enough information so that I wouldn't have to have an amnio. She said it was available. After wavering back and forth for a month, I decided to go ahead with it. So at 17 wks I had the triple screen. The nurse told me they were moving in the direction of phasing out AFP only and doing all triple screen. Well, you guessed it. The next week my Dr. called and told me that based on the test my chances for Down's were 1 in 180 rather than the 1 in 800-or-so that they should be for my age. The AFP number and the estriol number were normal, but the HCG number was 3 and a half times the median. Luckily I was able to get an appointment the next day for the level 2 U/S and possible amnio. I was still hoping to avoid the amnio, and I figured that they could look for signs of Down's on the U/S. When we got there, the genetic counsellor told us that the HCG value was the most sensitive of the 3 numbers - that a Down's baby could cause that number to go up and leave the other numbers in the normal range. Also the perinatologist told us that most Down's babies look normal on U/S. She would increase someone's risk estimate if she saw certain things on U/S, but she would never decrease it based on not seeing anything abnormal. I think I was under the U/S for about a half hour. No signs of Down's were seen, which made me feel a little better, but based on the stuff above, we decided to have the amnio. The procedure itself wasn't that bad. It pretty much felt like getting a shot or getting blood drawn, although I could tell when the needle hit my uterus. But I was terrified because there is about a 1 in 200 chance of losing the baby this way, through the water breaking or through infection. They said any fluid problems would occur within 48 hours, but an infection could develop slowly over 2 weeks, and the baby could die without my noticing anything wrong. They told us it would be 10-14 days before the results were ready. I was relieved after a couple days when I hadn't had problems. One bad possibility down and two to go. Then the agonizing wait for the results. I was terrified every time my phone rang. But then luckily on the last day before we were to leave town on vacation, I got the call with good results!!! Two down and one to go. We weren't sure whether we wanted to know the sex early, so I told them to put it in an envelope and send it to us so we could decide later if we wanted to open it. Every day on vacation I made sure I could still feel the baby move, and my Dr. heard the heartbeat at my next appointment, past the danger time for infection. Whew! I guess all's well that ends well, but I'm a little upset that despite how informed I was about the AFP and all, that I still went through exactly what I was trying to avoid, and that I put my baby at risk. It seemed like each individual decision that we made, made sense by itself, but when you look at the whole experience it was a series of escalating interventions, which is the same thing I'm afraid of happening to me in labor. In fact, I feel like I started it, since if I hadn't said anything, I would probably have just had the AFP alone, which was normal, and not had to go through it all. Maybe the risk of false alarms and amnios is just the price that has to be paid by people like me who want to know early if anything is wrong. Physically this has been an easy pregnancy for me so far. I didn't have bad sickness in the beginning, and I've felt great all through this 2nd trimester. But emotionally it has been very difficult, first with two spotting scares early on and now this. I just want the baby here and safe. On a lighter note, I got some more U/S pictures of the baby, including one of it sucking its thumb. They said the baby was really active. Now we've got the envelope with the baby's sex written in it, sitting at home tempting us. I found out they told my Dr. the sex, too, and it's right in my chart! She didn't know I didn't know, so it's a good thing I mentioned it before she let it slip. I just don't know if I want to know ahead of time or not. Part of me thinks it's silly not to look at the information that's available. But on the other hand, if we knew then it would be hard to keep the secret from others, and I don't want to get sexist gifts like clothes with pink frills or footballs. The knowledge of the gender can be misused for sexist inculturation, so maybe it's an advantage for the baby to stay gender-neutral, at least while we're shopping for nursery stuff and clothing. I'm trying to think of advantages and disadvantages either way. Anyway, for those of you who have read this far, thanks for listening, and celebrate with me that this scare is over! -----------------------------------------