u/UnverifiedPanda

I’m currently awaiting the results of a second amnio after being diagnosed with low-grade mosaicism T21. I’m 21 weeks pregnant now. We’re not sure what we’ll do if these confirm the previous results.

I feel it’s getting harder and harder to deal with people. Just anyone. I don’t feel like talking to my closest friends, while simultaneously I’m disappointed when they don’t reach out or respond in a way that feels right. Whenever I do meet or talk with them, I just feel exhausted afterwards.

I struggle to determine what to tell people who are not in my direct inner circle. I don’t like hiding my pregnancy but obviously I don’t feel happy about it at the moment. If someone happily asks about my pregnant belly, I tend to respond in a “yes thanks but…” manner but the levels of details I give are different. Sometimes I say there’s complications. Sometimes I say there’s a genetic abnormality without specifying what. Sometimes I say it’s Down, leaving out the mosaic part. And sometimes I just try to explain, but the situation is so complex that it’s hard.

Obviously, the responses vary from being empathetic and understanding to mentioning how cute and fun children with Down are. It never got directly judgmental for me (yet) but it makes me miserable either way.

I notice I’m avoiding people more and more. It feels more comfortable in my own bubble, but I also feel very alone. It’s very unlike me to close myself off.

How are you dealing with people around you? How much do you tell them? Any tips?

Hi all,

I’m trying to understand the differences between the following prenatal tests:

- FISH
- QF-PCR
- karyotype
- aCGH array (CMA)
- SNP array (CMA)

After a high risk NIPT for T21, they ordered a combination of QF-PCR, SNP array and karyotype for me. Culture cell due to maternal cell contamination. QF-PCR came back normal, SNP returned 8% mosaicism.

Is there a specialist here who can explain to me the differences between the tests above in terms of (1) method/classification, (2) number of cells, (3) effect of cell culture, (4) detection thresholds and sensitivity/specificity, (5) fit for low-grade mosaicism?

I feel I have some basic knowledge by now but I seem to be reading some conflicting information, especially about the impact of cell culture and low-grade mosaicism.

Any insights would be greatly appreciated!

Hi all,

I posted before about our case: https://www.reddit.com/r/NIPT/comments/1u3qr8m/nipt_positive_t21_no_soft_markers_waiting_for/

The summary is that we received NIPT results indicating high risk for T21, but then the QF-PCR test came back normal. They were still doing an array test to check for low grade mosaicism, and while we were told that those chances are very low, I just got a call that the array test showed 8% mosaicism.

Our doctor told us that, basically, very little is known about the impact on the baby. We will get a consult with a genetics specialist, but I don't know how much they will be able to tell us. We're devastated by this uncertainty.

At this moment, we're just desparate for more information. I'm almost 20 weeks now and I just don't know what to do.

Does anyone have experience? Of know about research on low grade mosaicism for T21?

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EDIT: Here's a translation of my lab report.

Due to the blood-contaminated appearance of the amniotic fluid, no result could be obtained from DNA extracted from the uncultured amniotic fluid sample. Therefore, a QF-PCR test and additional SNP array analysis were performed on DNA obtained from cultured amniotic fluid cells.

In addition to the previously performed QF-PCR test, SNP array analysis was carried out on DNA obtained from the cultured amniotic fluid cells. This analysis revealed an average increased probe dosage of approximately 8% for chromosome 21. This finding is consistent with low-level mosaic trisomy 21 (Down syndrome). The fetus is female.

The indication of trisomy 21 detected by the NIPT screening is therefore also identified in mosaic form in the amniotic fluid. The mosaicism of approximately 8% proved too low to be detected by the QF-PCR test and is therefore not reflected in the earlier QF-PCR result.

It should be noted that, due to the blood-contaminated nature of the amniotic fluid sample, the diagnostic testing was performed on cultured cells. Consequently, a potential culture effect cannot be excluded. This means that the estimated 8% mosaicism is based on cultured amniotic cells, and the percentage may differ somewhat in DNA obtained from uncultured cells.

The clinical implications of mosaic trisomy 21 are uncertain, because the proportion of abnormal cells can vary substantially between different tissues and organs. As a result, the phenotype may range from relatively mild features to the typical features associated with Down syndrome.

Genetic counseling is indicated to further discuss and explain this finding.

Additional karyotyping will be performed on the cultured amniotic fluid cells to investigate whether the mosaic trisomy 21 may be caused by an unbalanced Robertsonian translocation involving chromosome 21.

Disclaimer: Special attention was paid to chromosome 21. The remainder of the genome was assessed at a practical resolution of 0.5 Mb.

Hi everyone, I’m 35 years old and I’m from The Netherlands. I’m currently 18w1d pregnant. At 14w5d the NIPT came back positive for T21 and I’m currently in limbo waiting for the results of the amniocentesis taken 2 weeks ago. This is my third pregnancy. 

My first pregnancy ended in stillbirth. The 20-week ultrasound showed a severe growth restriction due to placental insufficiency, and after a few weeks of hoping the baby would reach a certain gestational age and birth weight, I developed the HELLP syndrome. Our son was stillborn at 24w2d. I was devastated by our loss and the birth was a traumatic experience. I was seriously ill and could not use pain medication due to my condition, so the contractions felt unbearable. I had to recover in the hospital for weeks, where I held our baby and cried a lot. I was depressed for months, but time healed wounds and I was able to enjoy life again.

For my second pregnancy, I was monitored more extensively and put on preventive blood thinners due to increased risk of recurrence. We were nervous for the entire pregnancy but as the baby was growing steadily and my blood pressure remained stable, we slowly gained more trust. We initially tried to induce labour by balloon catheter around 39 weeks, as advised by our doctor as a preventive measure, but this failed two times and I hated it. After the second attempt, we decided my body and the baby were simply not ready yet and that we would wait for the birth to start naturally. Our daughter was born healthy 9 days later at 40w6d, after a wonderful and relaxed time. To choose trust over fear was such a healing experience - I can still cry from gratitude for making that decision. Our daughter is now 3 years old.

My third pregnancy started a bit insecure again. But as I was longing for that feeling of faith and trust in this pregnancy again, I decided I did not want to go to the academic hospital anymore, not until there would be worrying signals, and continued the regular checks at the local ultrasound center. Of course, I was taking preventive medicines again and after 20 weeks I would get extra ultrasounds to monitor the growth at the local hospital. Somehow, this felt similar to our decision to stop the labour induction process during the previous pregnancy. But then we received the NIPT results: T21. My world crashed. Out of all scenarios I mentally prepared for, this was not one of them.

In The Netherlands, the NIPT is now a standard and free procedure. This is great, but I think we get less information about the results than I see mentioned in other posts. I don’t know the fetal fraction or the positive predictive value (PPV). I was just told that for T21 the chances are 90-95% that the NIPT is correct, which seems right, but I do wonder about these other numbers and if they could tell me anything more. The ultrasound did not show any soft markers. This leaves a bit more hope for a false positive, but I know it does not have to mean anything.

We did an amniocentesis. We expected results in 3-5 work days from the QF-CPR but due to maternal cell contamination, this test was indecisive. So now we are waiting for the karyotype results. We don’t know how long this will take. The phone can ring at any time, but we might also have to wait another week (or even more?). This limbo phase is really difficult. I don’t know what to feel or think.

We tried to stay away from thinking about the decision until we have a definite diagnosis, and I think we’re scared to say it out loud. But I think we would TFMR if T21 is confirmed. After losing our son, I never thought I would have to make a decision like that with a baby that does have a chance of living a good life. I feel guilty even thinking about it while we are not even certain yet. We're getting close to the date our son was stillborn (22nd of June) exactly 5 years ago, which seems like a cruel joke. We know it’s a little girl. I want to give her my love, independent of the outcome, but I feel scared to attach too much. It’s all just so confusing.

All I can do is hope for the results to come in soon, so that we can at least move forward.