Triploidy

If you've found this page via Google search for "triploidy" I would imagine that you or someone you love has recently heard that term in relation to a precious little one you are eagerly anticipating.  There's not a lot of information about triploidy, and the diagnosis can be devastating to families.  This is a compilation of what I've researched about the condition.  I hope that you'll also stick around to read some of our story, and our journey with our daughter, Whitney Jill.   

Triploidy is an extremely rare chromosomal abnormality.  It is caused by the presence of a complete extra set of chromosomes.  Never heard of it before?  Neither had we.  When we were sent to the Children's hospital, some kind of chromosomal disorder was suspected because of the abnormalities we saw on our 19-week ultrasound.  Some of the 'markers' or indicators that were present on Whitney's ultrasound were: three echogenic foci on her heart; her belly was measuring smaller than her head; all her measurements were a couple of weeks behind where they should have been; extremely low amniotic fluid level.  Some of these conditions completely rectify themselves in other pregnancies.  But in our case, the presence of multiple markers indicated a significant problem, most likely associated with some kind of chromosomal abnormality.  There are a number of different abnormalities that could potentially indicate triploidy.  Abnormal sonogram findings include (from Healthline):

• severe early-onset intrauterine growth retardation (detected as early as 12–14 weeks)
• brain abnormalities, including isolated ventriculomegaly (enlarged ventricles), Arnold-Chiari malformation, holoprosencephaly, andagenesis of the corpus callosum
• cleft lip and possible cleft palate
• limb abnormalities, such as clubfoot or syndactyly (webbing of fingers and toes)
• heart defects
• kidney abnormalities
• abdominal wall defects, such as an omphalocele (an opening in the abdominal wall, which causes the intestines to be located outside the body)
• neural tube defects, such as spina bifida (an opening in the spinal cord)
• oligohydramnios (a decrease amount of amniotic fluid)
• placental abnormalities, including an enlarged placenta or a cystic placenta

The most common chromosomal problems are Downs Syndrome or another one of the Trisomies, like Trisomy 18.  (A trisomy is simply the name for a genetic abnormality in which there are three copies of a particular chromosome, instead of two.)  To break it down simply, most healthy, normal babies have two sets of choromosomes... 23 from the mother and 23 from the father.  That makes a total of 46 chromosomes.  Here's what a "normal" set of human chromosomes looks like:

Image from http://ghr.nlm.nih.gov/

 But in the case of a trisomy, one of the sets of chromosomes has an extra copy of one... giving that baby 47 chromosomes.  Each set of chromosomes is numberes... one through 22, plus the sex chromosome, 23.  Generally, the trisomy is named after the number of chromosome that is triplicated.  Downs Syndrome is techincially T21; Edwards Syndrome, or Trisomy 18 is another common trisomy.  
While each of these trisomies contains one extra copy of a certain chromosome, triploidy is unique in that there is an extra copy of not just one chromosome, but every single chromosome.  A baby with triploidy has 69 chromosomes instead of 46.  Here's what the chromosomes of a Triploid baby look like:

Image from http://ghr.nlm.nih.gov/ 

You can clearly see the extra chromosome set.  There is no mistaking what this is... We actually got a copy of Whitney's chromosomal 'picture' and here is what an actual printout of the karotype looks like:

 

So what causes triploidy?  Triploidy occurs in several different ways. The extra set of chromosomes can be inherited from the father (paternal inheritance) or they can be from the mother (maternal inheritance). The most common mechanism for triploidy is the fertilization of a single egg by two sperm. This results in a triploid egg with two sets of paternal chromosomes and one set of maternal chromosomes. This accounts for about 60% of cases of triploidy. The other mechanism is an error in cell division in which an egg cell ends up with 46 chromosomes instead of 23. This egg with 46 chromosomes is fertilized by a sperm with 23 chromosomes, resulting in a fertilized egg with 69 chromosomes, which then has two sets of maternal chromosomes and one set of paternal chromosomes. This mechanism is responsible for about 40% of cases of triploidy. (from Healthline)

Triploidy is a fatal condition.  It occurs in 1-2% of all conceptions.  However, most babies with triploidy spontaneously miscarry early in the first trimester.  Very few triploid pregnancies go to term, and only one in every 10,000 infants is born with triploidy.  It is estimated that for every live-born infant with triploidy, 1,200 have been lost as miscarriages. Most infants with triploidy that do make it close to term are either stillborn or die shortly after birth. 

From everything I have read and been told by our genetic counselor, triploidy is a completely random occurence.  It is not caused by any action of either parent.  And while it involves genetic components, it is not a condition that is passed down genetically.  It is also not associated with the mother's age.  Statistically speaking, a woman who has had one triploid pregnancy is not at any greater risk than anyone else to have another triploid pregnancy.  However, I have met a handful of women who have had multiple triploid pregnancies.  The geneticists still tell them they are at no greater risk than anyone else.  I think that a lot more research needs to be done in this area before anything can be  known for sure.  (Just my opinion!)  That said, I do know many more women who have gone on to have multiple, healthy pregnancies after a triploid loss.  

Generally speaking, the recommended course of action when triploidy is confirmed (generally by amniocentesis or CVS) is termination.  However, as you may read through out this blog, that is not the only course of action available.  I believe that too often, women are quick to follow their doctors' orders, instead of seeking out what is best for them.  Though termination may be recommended by a doctor, I would encourage anyone in a similar situation to take time to consider their other option of continuing to carry the pregnancy.  (Unless of course, your health is in direct jeopardy.  Generally, this means high blood pressure and other signs of toxemia that your doctor will check you for.)  This is an extremely personal decision and not one that should be made hastily.  Take time to consider your options, away from the doctor's office or hospital.  Talk to your significant other.  Take a day or two to sleep on it.  Do not be pressured into something that you have not taken time to consider.  

Of the few babies who survive to term with triploidy, there is a specific pattern of abnormalities that may be seen in their physical characteristics.  Here are some of what may be evident at birth(from Healthline):

• Almost all of these infants will have growth retardation  
• Wide-set eyes (hypertelorism) 
• Low-set ears
• Cleft-lip or palate
• Limb abnormalities (such as clubfoot and syndactyly (webbing of the fingers and toes)
• Heart defects
• Kidney malformations
• Genital malformations (particularly in males)

Before Whitney was born, I was really nervous about how she would look.  We couldn't see her very clearly on ultrasounds, because her amniotic fluid levels were so low.  As soon as Whitney was born, the nurse took her over to the bassinet to clean her up and take her measurements.  She kept telling me that Whitney was absolutely perfect.  All of her imperfections must have been on the inside.  When I was able to hold her, I was a little surprised at the way she looked, but it was only because she was so small.  Not even a pound.  But the nurse was right... anatomically speaking, everything on Whitney was perfect (at least on the outside).  I counted every finger and toe about 100 times.  I kissed her tiny, perfectly formed ears.  Her little lips were just so precious.  Every person's experience is different, but for us, Whitney was perfect.  But I've since realized that she would have been beautiful to us no matter what she looked like.   (There is a wealth of information on the Healthline website.  That is where this information came from, unless otherwise noted or linked.)  

I can only speak from personal experience when I say that continuing to carry our pregnancy as long as we could was the greatest blessing of my life.  I was able to give my daughter unconditional love every second that her heart was beating inside of her.  I did not choose the moment her heart stopped beating.  All along, we knew the end would be fatal for Whitney.  But we tried to make the most of every second she was with us.  I have no regrets about this decision.  I have met many women who have been faced with this horrible decision, and every single one who chose to continue the pregnancy until it naturally ended shared the same feelings of no regret.  If you have found yourself facing a similar decision, please hear my heart on this... I am not passing judgement or trying to manipulate a specific conclusion.  I simply want to share my experience, and allow others to make the best decision possible for them.  One that will render no regrets in the future.   

Through our journey, I have met several other women who lost their babies to triploidy.  Each one has a unique and beautiful story to share.  If you have found this website because you find yourself in a similar situation, let me first say I am so sorry.  No one should have to experience a loss like this.  The greatest information I have found has been through the firsthand experience of others.  That is why we've shared our story so openly.  If you have any questions, please don't hesitate to send us an email or leave a comment.  The best thing you can do is educate yourself and ask a ton of questions.  We've found that many in the medical community have never dealt specifically with a triploid pregnancy, so often, the care can leave much to be desired.  Even my delivery nurse had never heard of it-- I explained it all to her before Whitney was born!  But be an advocate for yourself and your baby... reasearch, ask questions, seek help and support.  

*Disclaimer* I am not a medical professional by any stretch of the imagination.  Everything I've written on this page is from research I have done on the subject, and I have linked to the sources of my information.  This is intended only to be a summary resource to direct others to those sources of information for their further reading.  Any opinions given are strictly my own.  :-)