Reader's Questions Related to Low PAPP-A in First Trimester Screening for Aneuploidy
Thursday, March 27, 2008
Kenneth F. Trofatter, Jr., MD, PhD
• At Sun Mar 23, 02:20:00 PM 2008, Anonymous said…
First of all I want to thank you for this wonderful website. This is the best PAPP-A site on the internet, and believe me I have seen all of them.
These are my first trimester screening results:
Nuchal (translucency) scan was normal
Free beta hCG: 0.7677 MoM
PAPP-A: 0.1358 MoM
This PAPP-A put me in high risk of a chromosomal abnormality. I did CVS (chorionic villus sampling) and results were normal. Now I am worried about nonchromosomal issues like placental dysfunction and restricted fetal growth. I have a number of questions:
1) For the blood test they dated my pregnancy based on the scan as 13 weeks. I am sure that I was 12wk 3d or 12wk 4d only. I read that PAPP-A doubles each 3 or 4 days during first trimester. I wonder if the result would not be so low if they would have dated my pregnancy as 12wk 3d or 12wk 4d. Would it be 0.2716 MoM instead of 0.1358 MoM?
Dr T: 3-4 days should not make any significant difference in the interpretation of the test and the MoM does not change at the same rate as the PAPP-A.
2) The fact that hCG is also low, does it mean anything?
Dr T: The hCG is NOT especially low.
3) What is the risk of placental dysfunction with PAPP-A levels as low as mine?
Dr T: The lower the PAPP-A, the greater the risk for intrauterine growth restriction and other complications (I answer this point more specifically in my post on “The Affect of Smoking on PAPP-A levels Detected in First Trimester Screening” on March 25, 2008)
4) I am a non-smoker but I am a passive smoker, could this influence the PAPP-A levels?
Dr T: Passive exposure to cigarette smoke could potentially reduce the PAPP-A levels (again, see the March 25, 2008 post) although I have never seen that addressed in the scientific literature! Maybe you should make the smokers in the family “take it outside” for your baby’s sake!
5) During the nuchal translucency scan, the baby’s size was found to be normal or even big for the age. Is this a good sign or it is irrelevant?
Dr T: I would rather see a larger baby than a smaller one at this point although it's probably irrelevant! Abnormalities of placentation usually are not reflected in effects on fetal growth until after 20 weeks’ gestation.
6) I have been advised to have a scan at 28-30 weeks to assess fetal growth. Should my doctors start monitoring this earlier? If there is placenta dysfunction, does it only start in 3rd trimester or could it start earlier? If the latter, wouldn't it be better to start monitoring earlier? You recommend serial assessment of fetal growth, what is the frequency and when to start? Same question for the Doppler.
Dr T: Placental dysfunction can lead to intrauterine growth restriction (IUGR) much earlier than 28-30 weeks. Although low PAPP-A levels are not invariably associated with IUGR, yours is low enough that I would consider assessment of growth at 24-26 weeks. If there is a significant abnormality of placental vascularization (not just a small placenta), Doppler flow studies can often detect those that early, even before the baby starts to fall off the growth curve. If growth and Dopplers are normal at that time, I would probably repeat both studies about 4 weeks later (28-30 weeks). Based on that later study, I would then decide if further fetal evaluation is necessary.
7) Is it worth buying my own blood pressure monitor to control the preeclampsia risk? My doctor will only test me every 3 weeks.
Dr T: Just go to a local pharmacy. Most of those have blood pressure devices that you can use for free and they are more accurate than if you did it yourself (P.S., Remember to relax and uncross your legs while you are having your BP checked!).
8)Is the low PAPP-A level and placental dysfunction related to the age (I am 36) and do I have more chance of having the same issue in a future pregnancy?
Dr T: It is conceivable that your age is contributing to a suboptimal site for placentation if you have had, for example, many previous pregnancies or D&Cs, or have a uterine septum or adhesions, or uterine fibroids. Chance of recurrence is going to depend on why it happened this time! One of the old adages in obstetrics, however, is that "history tends to repeat itself" even if we aren't smart enough to figure out why!
9) Is there a link between restricted fetal growth and cerebral palsy?
Dr T: There is a greater risk for both cerebral palsy and developmental problems in growth restricted babies that is dependent on the actual reason for the IUGR. Examples of causes for IUGR include congenital infections such as cytomegalovirus (CMV), chromosomal abnormalities, genetic problems or syndromes, placental insufficiency, premature delivery, and maternal preeclampsia are the most common.
Anyway, I hope this helps. Any more and I would have to send you a bill for my time! (JUST KIDDING). Great questions and good luck for the rest of the pregnancy. Let us know how things turn out, MJ!
Dr T
Labels: aneuploidy screening in first trimester, first trimester screening, PAPP-A
19 Comments:
At Fri Mar 28, 12:20:00 PM 2008,
Anonymous said…
Dear Dr T, I am currently 29 years old and 14 weeks pregnant. This is my 4th pregnancy. My first pregnancy was uneventful until I suddenly developed HELLP Syndrome at 35 weeks. My healthy 6 pound daughter was delivered with no complications. 2 years ago I had a missed miscarrage at 8 weeks and in October of last year I lost my second daughter at 37 weeks due to a placental abrubtion. I took baby aspirin and extra folic acid during this pregnancy. After we lost our daughter I had a complete workup and was found to be heterozygous for Factor V Leiden. No other blood disorders and I am otherwise in perfect health. I have no family or personal history of blood clots. I am currently on Lovenoz 40 mg/day, baby aspirin, extra folic acid and prenatals. My perinatologist, OB and hemotologist are all optimistic. I am scared to death! I worry about losing another child or having a problem myself when I already have one at home to raise. All ultrasounds show normal healthy growth. Do you have any other reccomendations besides my current regimine?
At Sat Mar 29, 05:48:00 PM 2008,
Anonymous said…
I am 37 and I had four miscarriages in the past year. First mc was trisomy16 and the others were all naturally passed. I went to a high risk ob and he did all types of bloods on me. Everything normal. Now I am on a variety of meds. I can get pregnant but I can't go beyond 8 weeks. So now I'm taking clomid, prednisone,levonox, progesterone, baby aspirin, prenantal with vitamin B and Folgard. Does this seem normal? I just really want to have a baby!!!!! And is all this good for my body. The dr. did explain everything but i wanted some advice....
At Sun Mar 30, 07:56:00 AM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To Anonymous Mar 21: No other suggestions at this time - it looks like you are in good hands. Your doctors will probably couple assessment of fetal growth with Doppler flow studies later in pregnancy. All they can do is keep a VERY close eye on the baby and 'bail out' at the first sign of any real danger. Good luck to you and let us know how things turn out.
Dr T
At Mon Mar 31, 10:32:00 AM 2008,
Anonymous said…
DR T - I'm interested in your comments. I'm 38 and recently did my ultrascreen test. My beta-HCG was 2.06, my PAPP-A was 0.50, and my NT was 2 mm. How concerned should I be? Is this PAPP-A number cause for conern?
Also, I had spotting (because of a low lying placenta) during weeks 7, 8, and 11. Could this be related?
Thanks so much -
LR
At Tue Apr 01, 06:21:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To LR: Without the master computer at my fingertips, I presume that combination of findings with your age puts you at increased risk for having a baby with Down syndrome. What was your actual risk assessment?
Dr T
At Wed Apr 02, 05:52:00 AM 2008,
Anonymous said…
The risk that the lab reported was 1 in 15. I'm just wondering about other causes of the low PAPP-A and the high HCG.
A nasal bone was detected at my 11 week u/s. Is that good news?
I'm very anxious about all of this, as you can imagine.
Thanks for your time -
LR
At Thu Apr 03, 04:31:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To LR: I was afraid you would tell me that. The presence of a nasal bone can be reassuring, but if that was reported, then any risk reduction associated with that has already been included in the risk calculation. I know in "high risk" situations, no correction for nasal bone is sometimes included. You need to consider your options for fetal diagnosis, but I sense you would benefit from knowing for sure and the only way to find out is to have an invasive diagnostic study done. I am sure you have discussed your options in this regard with your doctors, so good luck with your decision and the outcome. Please let us know what happens. Thanks again for reading! Dr T
At Thu Apr 03, 06:29:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To Anonymous Mar 29: With that history of repetitive miscarriages and your age, I would offer you a regimen very similar to what you are taking. It is 'empiric therapy' but it is also safe enough for pregnancy under your circumstances. Good luck and thank you for reading. Dr T
At Thu Apr 03, 06:51:00 PM 2008,
Anonymous said…
Hi Dr T -
In reviewing my lab report, I notice that the dates are incorrect. My blood draw was on 3/24/08, but the report indicates that it was on 3/20. So they did their calculations under the assumption that it was 4 days earlier in the pregnancy. My HCG was high, PAPP-A low, fitting the profile of Trisomy 21. As I understand things, HCG levels drop and PAPP_A levels increase over the course of the pregnancy. Sp does this date mistake indicate that the results are even worse than what was reported?
At Fri Apr 04, 04:19:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To anonymous Apr 3: It is my understanding that teh laboratory does not usually make adjustments if the difference between actual gestational age and reported gestational age are only 4 days. So, the final result would still put you at increased risk for trisomy 21. Thanks for your questions and please let us know how things turn out. Dr T
At Sun Apr 06, 07:54:00 PM 2008,
Anonymous said…
Dear Dr T, I would be 37 at delivery and my Integrated Screening results are:
At 13w1d,
NTS 1.6mm or 0.86 MoM
PAPP-A 2350.5 mU/L or 0.48 MoM
At 16w5d,
Serum hCG 75.1 IU/mL or 2.33 MoM
Serum AFP 43.5 ng/mL or 0.82 MoM
Screen positive at risk 1 in 150.
Whether the hCG is total or free beta is not known. I'm kind of denying/disbelieving the results as they look so textbook-like. Anyway I am considering an amnio in this week. In the event that the amnio is negative, how should I take the screening results above? or what did they say about aspects of my prenancy that I should watchout for in the remaining months?
At Tue Apr 08, 04:47:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To anonymous Apr 6: I don't have my tables in front of me, but the calculated risk is probably slightly less than your age alone first trimester risk for having a baby with Down syndrome. Being "screen positive" does not mean you are any higher risk than the 1 in 150, it just means that you fall above the cut-off of 1 in 250-300. Odds are in your favor that the baby is chromosomally normal, but if you want to know for sure, then the amniocentesis is the way to go. An alternative that is frequently considered at this more 'intermediate risk' level is to have a 'genetic sonogram' done by a specialist in Maternal-Fetal Medicine or Radiology at 18-20 weeks. If the baby has no major abnormalities or 'soft markers' for aneuploidy, then your a priori risk (based on the first trimester screen result)is reduced by 60-80%. That would put you in the range of 1 in 400. Of course, if something suspicious is seen at that time, you could still proceed with an amniocentesis. The choice is yours! Thanks for reading, good luck, and let us know how things turn out. Dr T
At Mon Apr 21, 07:35:00 AM 2008,
Anonymous said…
I am 37 (Age at EDC:38) I recently had an ultra screen with an increased risk for down syndrome. The results are:
NT 1.3
hCG(MOM) 3.15
PAPP-A 0.54
NT 1.3
CRL(mm) 53.5
Are these numbers really a cause for concern??? I cannot find what "normal" should be for these tests. I have to see a genectic counselor at the end of the week, but I feel like I've aged more in these last 5 days then in the last 5 years!! I also have a healthy 3-y-0 boy. Thank you for any help or advice you can give.
At Mon Apr 21, 07:36:00 AM 2008,
Anonymous said…
I am so sorry, I think I left my question a few times on your site. I am so sorry for the trouble, but I would greatly appreciate it if one could be left for the Doctor to answer. Thank you again.
At Mon Apr 21, 05:57:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To anonymous Apr 21: We don't like to talk about "normals" when we evaluate the serum markers and the other measuremenst we plug into risk assessment in first trimester. There is continuous variation and the important factor is how the combination of values are related. In your case, the high hCG combined with the low PAPP-A and your age probably place you at fairly high risk for Down syndrome. What was the actual risk you were given? Even then that does not absoluetly mean the baby has Down syndrome. Remember, it is just a screening test, but it is an indication for us to offer you invasive diagnostic testing if you want to find out for sure one way or the other. Best wishes and let us know how things turn out. Dr T
At Tue Apr 22, 07:06:00 AM 2008,
Anonymous said…
My OB gave me a fraction of 1/28. I saw a genectic counselor yesterday, they were able to get me in earlier, and she said that turns into a 96% chance the baby is fine and a 3+% for DS. Which to me just "sounds" much better than that fraction. Now I have to decide about the amnio, which also scares me due to the chance for miscarriage. She said their rate at the facility is 1/400. So, I'm still on the fence but need to make a decision soon as I am 13 weeks and would need to schedule this for 16w. Any other advice on the amnio??? Thank you so much again and I'm so glad I found this site!!!
At Tue Apr 22, 04:42:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To anonymous Apr 22: Consider scheduling the amnio and then waiting to make your final decision about having done until afte the ultrasound is performed. Lots may play into the final decision - the growth of the baby, findings of any abnormalities, the placental location, etc. The risks your office quotes are very good and their actual rates are probably even better than that which they are quoting you. It is a fairly safe and simple procedure. Good luck with things and please let us know how everthing turns out. Dr T
At Sun Apr 27, 12:51:00 AM 2008,
Anonymous said…
I'm 34. First pregnancy (3rd ICSI). Grow restriction- head, leg normal , CRL smaller (48 mm at 13 week). Extremly low PAPP-a =0,02 MoM and HCGb=0,04 MoM
What could be the reasons for such low Pappa and hcg values ?? What are the chances for normal baby. I am waiting for amnio. What else shoud I check ? (I had severe adhesions in uterus)..
At Wed Apr 30, 05:45:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To anonymous Apr 27: I don't beat around the bush. If you are really 13 weeks and the crown-rump length of the baby is consistent with 11 weeks, then the prognosis for the pregnacy is poor. The baby most likely has a chromosomal abnormality or an exceedingly poor site for placentation because of the intrauterine synechiae. The only other common problems under these circumstances are a congenital CMV infection or a severe genetic disorder, but both of these are much less likely than the first. Please let us know how things turn out. Dr T
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