Trisomy 18

The results of our chromosomal testing are in.  The reason for our miscarriage is that our baby had Trisomy 18.  Basically what this means is that our baby had an extra #18 chromosome, instead of the normal two.  The medical complications of Trisomy 18 are potentially very life-threatening in the early months and years of life.  50% of babies that are carried full term are stillborn.  Of those that survive and are actually born, less than 10% make it to their first birthday.

Statistics show that there is a very high mortality rate for babies with Trisomy 18, either before or shortly after birth.  Typical characteristics of Trisomy 18 are:

Heart defects:

• VSD (Ventricular Septal Defect): a hole between the lower chambers
• ASD (Atrial Septal Defect): a hole between the upper chambers
• Coarctation of the aorta: a narrowing of the exit vessel from the heart

Kidney problems

Part of the intestinal tract is outside the stomach (omphalocele)

The esophagus doesn’t connect to the stomach (esophageal artesia)

Excess amniotic fluid (polyhydramnios)

Clenched hands

Pocket of fluid on the brain (choroid plexus cysts)

Rocker bottom feet

Delayed growth

Small jaw (mycrognathia)

Small head (microcephaly)

Low-set ears

Strawberry-shaped head

Severe developmental delays

Umbilical or inguinal hernia

A small number of adults (usually girls) with Trisomy 18 do live to be in their twenties and thirties, although they have significant developmental delays that do not allow them to live independently without a caregiver.

I am so, so glad that we had the chromosomal testing done.  We both feel much better about the miscarriage considering the road that would have been ahead for us.  I would much rather have lost our baby at this early stage, than carry it full term, only to have a stillborn. 

We know that the extra chromosome came from the egg.  The genetic doctor that I talked to said that usually happens with older parents.  With my sister just being 32 and having already delivered 3 healthy babies, she said the odds of this happening were about 1%.  The other embryos are most likely okay.  There is probably no greater than a 1% chance of this happening again using the other embryos.

They can do genetic testing on the other embryos for abnormalities, but that can also be harmful to them.  With only 2 embryos left (and only one of them being viable most likely), she said she wouldn't recommend doing the testing since the odds of anything being wrong with them are so low.

Since my sister is planning to have one more child herself, I also asked if Sis would be at risk of having a Trisomy 18 baby.  The doctor said the chances are extremely low.

Knowing that there is nothing that I did wrong during the pregnancy, and knowing that there is nothing that we could have done different, makes us feel so much better.  It is also really reassuring to know that the miscarriage was not due to me having a hostile uterus.  There is no reason indicated that I would not be able to carry a baby full term.  In this instance, nature just took it's course because we had a genetic abnormality that is very rare.

While it really sucks that this had to happen in the first place, I am very glad to know that there is nothing that we could have done differently.  I am also glad that nature took it's course and saved us from making some very difficult decisions down the road.  I wish that it was a normal, healthy baby and pregnancy.  I wish that we weren't in the 1% category.  But wishing doesn't do any good and it doesn't change our outcome.  All we can hope for at this point is that those last two embryos turn out to be our take home baby(s).

*The Trisomy 18 info in this post was found at the Trisomy 18 Foundation website.