I'm just back from my 20-week appointment where my doc told me that the results of my 16-week blood tests showed elevated AFP (apparently the upper acceptable limit at 16 weeks is 82 and mine was 103, whatever that means...). He hadn't contacted me to let me know because I have had ultrasounds every month since the start of my pregnancy and in his opinion he would have spotted any abnormalities before now and so he believes the test is probably false. Although he added that it could also indicate a mild form of spina bifida.
He performed another ultrasound today and took the necessary measurements and seemed confident that everything looked fine. I have to go back for a routine detailed morphology ultrasound in two weeks. He said that he wouldn't recommend an amnio unless something showed up on the ultrasound.
Although I was worried I was pretty much reassured by what he said until I did the unmentionable - GOOGLING! I took antibiotics at the very start of my pregnancy (before I knew I was pregnant obviously) - I told my doc at the time, but he assured me that it wasn't a problem. But I have just discovered that this antibiotic (Clarithromycin) is associated with spina bifida. And so I'm thinking now that my test probably isn't a false positive...
I was going to ask if anyone had any experience of having had a false high AFP reading, but now with the added concern of the antibiotic I don't suppose anyone will be able to relate or reassure. I'm waiting for my doc to return my call because I want to remind him that I took this antibiotic in case that changes his opinion. And I'm trying not to let anxiety get the better of me in the meantime...
I'm so sorry that you are stressed and concerned about this. In my humble opinion, you should follow your doctor's lead on this one. There are a number of false positives with the AFP test and I had just quoted a part of a book, "The Joy of Pregnancy" on another post in Feb 10 Babies forum to a woman having an amnio today about this same thing, really.
High readings can be because you are further along than anyone realizes which is very common. I think that if there were other markers, like your doctor said, it would be more reason for concern.
I know that it's much easier to sit on this side of the computer and tell you to be calm, have faith and stay relaxed. And if you ever go back to read any of MY posts, you will know that I am the biggest hypocrite who is full of doo-hicky....LOL. Not to make light of your situation, but I just know that I wouldn't be able to sit back, be calm and relax, but I do think it's what we SHOULD do :)
Good luck and I'll add you to my prayer list today! There's a lot going up today so you are in good company!
I work in a hospital and we use the Micromedex drug system and when you enter in a drug name it will give you every risk associated with the drug, especially reproductive risk. The reserach study results can be very distrubing, so I'm not so sure you would want to read it. If you want me to post it for you, I will. Just let me know.
I posted the link to this article, but MedHelp deleted it so here's the article in it's entirety! Hope it helps a bit! If you search false positives high AFP test, you will find other sources as well!
Understanding the AFP test
When 32-year-old Shelley Roberts of Sacramento, California was contacted by a nurse from her obstetrician's office calling to reveal the results of her recent blood test she immediately handed the phone off to her husband. Roberts, the mother of a three-year-old son, could not bear to hear that her blood test had come back abnormal, suggesting her unborn child had a risk for possible birth defects.
"I was completely devastated. My test had come back 1/78 for Down Syndrome and they couldn't get me an appointment with the genetic counselor for two weeks," says Roberts. "Those two weeks were the hardest. I didn't sleep, eat or live."
Thirty-three-year-old Angela Williams of San Antonio, Texas, got the call at work. "I was told by the nurse 'Your baby tested positive for Downs.' I was speechless, and in total shock," she says. "Needless to say, I left work early that day in tears, calling my husband with the sad news."
What is the AFP test?
The Alpha-fetoprotein test (AFP) is a blood test given to women in their second trimester of pregnancy, usually between weeks 15 and 20. When a woman is pregnant, alpha-fetoprotein is produced by the fetus and mixes with the mother's blood. Alpha-fetoprotein can be detected in a blood sample taken from the arm, according to the Division of Research at Kaiser Permanente, a healthcare system in Northern California.
A high level of AFP can be an indication of a neural tube defect such as spina bifida. However, high levels of AFP can also indicate that the mother is further along in her pregnancy than realized and her due date needs to be recalculated. A high AFP could also mean the mother is carrying twins, according to Kaiser Permanente.
A low level of AFP can be an indication of genetic defects such as a higher risk of Down Syndrome (Trisomy 21) or Trisomy 18, a more severe and less common chromosomal anomaly.
Most AFP tests now also include testing of two or three more markers, says Dr Harold N. Bass of the Department of Genetics at Kaiser Permanente Medical Center in Panorama City, California. The triple marker test, also known as the multiple marker, measures levels of AFP, hCG and estriol. The quad screen measures the same as the triple, as well as another marker called Inhibin.
"In California, triple marker screening, with a screen-positive rate of 5.6 percent, has an overall Down Syndrome detection rate of 66 percent. The detection rate for Trisomy 18 is 60 percent and for open neural tube and abdominal wall defects, 80 to 97 percent," says Dr Bass, clinical professor of human genetics and pediatrics at the David Geffen School of Medicine at the University of California, Los Angeles.
Dr Bass says the expanded AFP screening, as it is called in California, is required by law to be offered to all pregnant women in the state. Patients in California are given the option to refuse the test and the follow up services. Most other states do not require that AFP/multiple marker screening be offered.
Once a patient receives an abnormal or positive AFP result they are then advised to schedule an appointment to see a genetic counselor, a health professional with a specialized graduate degree and experience in medical genetics and counseling.
"When I see a patient who had a positive screen for one of these conditions, I explain the difference between a screening test and a diagnostic test. A positive screening test does not mean that there is a problem, it only means that further testing is warranted," says Diane Masser-Frye, a certified genetic counselor at the University of California, San Diego Center for Fetal Diagnosis. "Traditionally, about 5 percent of women who take the AFP test will get a positive result, but more than 90 percent of those will go on to have normal babies."
When a patient meets with a genetic counselor a family history is plotted to determine if further testing is needed. The genetic counselor also explains the option of having a level II ultrasound which uses sound waves to give a detailed examination of the fetus and an amniocentesis, which is a test of the fluid that surrounds the fetus in the womb.
"Genetic counseling is helpful for patients so they can understand their testing choices, the risks they involve and other options they have," says Masser-Frye.
Williams, whose ultrasound and amnio results came back normal, says her only complaint has been that she wished her doctor had given her more information about the AFP test and the option of not taking it in advance. "We have tried to just put the bad experience behind us and focus on [the birth of] our healthy girl."
AFP tests can sometimes be wrong. This is called a false positive. One of the major complaints about the AFP test has been what is perceived as a high rate of false positives. "The screen-positive rate is not unacceptably high for a screening test," says Dr Bass. "Without such a rate, the screening test would pick up far fewer fetuses with Down Syndrome, Trisomy 18 or neural tube or abdominal wall defects."
When an ultrasound and amniocentesis returns normal, there are other explanations as to why a patient could have received an abnormal AFP test.
"An 'unexplained' elevated maternal serum AFP level might signify potential pregnancy complications down the line, such as maternal hypertension, preterm birth and poor fetal growth," says Dr Bass.
Roberts' case proved to be a false positive. She gave birth to a healthy baby girl by C-section. After having gone through months of stress and constant worrying, Roberts says it was all worth it. But would she take the AFP test again? "I myself would take the test again. Just to know if there is the possibility of a problem."
Genetic counselor Masser-Frye believes the AFP test should be available to all women should they chose to take the test. "I do recommend the AFP test for women who feel like they want to know about Down Syndrome, Trisomy 18 or spina bifida prior to delivery," she said. "For women who would prefer not to have any kind of prenatal diagnosis, taking the AFP is not necessarily helpful."
I had a 1:39 risk for downs by test. My baby is just fine, these tests have high false positive, and I think your dr. is right, markers would show up on ultrasound, and since they have not, you shouldnt' get too worked up. I know that doesn't help. I think you can still request amnio if you want to put your mind at ease.
I had not one but 2 tests come back positive for spina bifida. My OB sent me to have a level ll ultrasound done along with talking to a genetics counselor and after they did the ultrasound for 2 hours looking at absolutely everything in my baby, they said he was fine and that they were not worried. The way they told me, if you are over 35 then you are more likely to get a false positive then a negative at any time! The counselor said she would rather they threw those tests out the door because all they are is a huge scare most of the time to women over 35! My son is now a happy, healthy, bouncy, dancing 15 month old!
It is also my understanding that in the very beginning of your pregnancy, not sure what time line exactly but early on there are no risks taking medications. I could be completely wrong about this and if someone wants to clarify that would be great, but that was what was explained to me.
Good Luck! I am sure your baby is fine! Please keep us all updated!
Patty - you are right about the no risk thing. Early on in your pregnancy, the baby isn't getting anything that's in your blood, so there's no risk. I don't know when it starts or anything, but my cousin told me the same thing when I was concerned about having been drinking during my tww.
Thank you SO much for your replies. We have decided not to mention this to family or friends because we don't want everyone stressing, so I think it did me good to unload all my worries here yesterday and even better to discover all these helpful, reassuring responses!!
My doc got back to me and didn't seem at all concerned about the antibiotics. So I know now I just have to trust him and think positive.
I will indeed keep you updated. Thanks again - I really appreciate it.
I am with the other ladies on this one..there are so many false positives on these tests...
Im sure in your case its probably what happened...if your Dr doesnt seem alarmed as you said..the next u/s is just a next precautionary step thats all..
Stay positive...I know its a hard thing to do right this minute! But I think like my girilfriends who had the same test results as you...all turned out to be fine..!
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