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Our Worst Case Scenario - Lethal Skeletal Dysplasias

Updated: May 10, 2022

So this is a post that hits hard at home for me, and even harder for a good number of parents out there who ultimately received a lethal diagnosis. But it is one that I feel compelled to write for a large number of reasons.

Ever since starting this blog, I get a handful of emails or Instagram messages every month from pregnant women or recent moms who are facing a skeletal dysplasia diagnosis. Some are lost, looking for some insight into what their future may hold - or are encouraged at seeing all of the pictures of Asher, who is a happy, smart, beautiful baby, who yes - has skeletal dysplasia. But many, are looking at a grim scenario such as the one that is described in my earliest posts - where the long bones have fallen very far behind, very early in the pregnancy - the doctors are telling them that it is a lethal form of skeletal dysplasia - and they are looking for some hope. And more than once, the moms are reaching out after they have terminated their pregnancy based on their doctors guidance, without having received a confirmed diagnosis.

As I have stated in my previous posts - there are currently between 300 and 500 different types of skeletal dysplasia (depending on who you ask). Achondroplasia is by far the most common type, with it accounting for such a large majority of all people with skeletal dysplasia that many people view the terms Achondroplasia and Dwarfism as synonymous. And let's be honest - having a baby with dwarfism, even Achondroplasia, is rare. Two average height people have approximately a 0.004% chance of having a child with dwarfism. Obviously - having been lucky to "beat those odds" and have a child with dwarfism, it isn't some foreign, never going to happen, the chances are so low, it may happen to other people but would never happen to me, type of concept to me. But it is likely that concept for most couples who do not have a child with the condition. It is frankly, unfathomable.

When you think of how many babies are born every year with dwarfism (the LPA has said that out of the 4 million babies born in the United States every year, approximately 400 of them will have dwarfism), think about what the chances are that the doctor you are seeing has had much experience with these babies. And when you take into account the fact that 70-80% of those 400 babies have Achondroplasia, that leaves 80-120 babies a year in the United States that are born with any one of the other 500+ types of dwarfism aside from Achondroplasia.

The sad reality is that many doctors will see extremely short long bones early in a pregnancy, which tells them it is most likely not Achondroplasia, and they will jump straight to telling a woman that her baby has a lethal form of skeletal dysplasia and it will be "incompatible with life". This is not a result of maliciousness, rather it is what comes with the territory of having a child with a condition that the doctor has very likely never seen before. Assumptions are made - and those assumptions can be very, very costly.

I could not even begin to tell you how many women I have spoken to who were told that their baby was not going to survive birth - some of which had planned the funeral and gotten all of the preparations ready for their baby to pass away immediately following birth - only to give birth to a kicking and screaming bundle of joy with dwarfism, who was otherwise perfectly healthy and who are now thriving. I remember so vividly the day that the doctor sat down with my husband and I and told us in no uncertain terms, with such a display of confidence and authority, that Asher either had a fatal chromosomal disorder, or would otherwise have an extremely severe, disfiguring, likely lethal form of skeletal dysplasia. Why would we not trust his guidance? He was, afterall, the specialist on the matter.

Hindsight is far more than 20/20 now though - as I look back. And I realize all of the questions that we should have asked then. Most importantly - tell me why you believe that? What are you basing that opinion on? Thankfully, when our amnio came back and ruled out any lethal chromosomal disorders, we decided to leave Asher's fate in God's hands and let him show the world what he was made of. But some stories do not have the same happy ending. We often put blind trust in these doctors, and do not think about the fact that they may be jumping to worst case scenarios, simply because they have never seen a baby like yours before. They do not understand how it would be possible for that baby, whose ribcage is unique, whose arms and legs are growing incredibly slow, whose vertebrae may have atypical spacing, to still be a perfectly healthy child - who is actually completely typical when you are looking at them through the lens of their genetic condition, as opposed to comparing them to a person without that condition.

Now - please don't get me wrong, this is certainly not the case with all doctors. But it is not a rare occurrence when it happens, which is heartbreaking to hear about, and even more heartbreaking to experience. So here are some very basic questions you can ask from your doctor when you are being told that your baby has a lethal form of skeletal dysplasia:

1. Ask them what type of skeletal dysplasia they believe it is. This question seems simple enough, and often they will respond by saying that they aren't able to tell at this point - but it makes them think. It forces them to either give you a diagnosis, or admit that they do not know what the diagnosis is (which then leads to the discussion around how they would know whether it is lethal or not, if they do not know what the type is).

2. Ask whether there is any evidence of fractures in the bones. Osteogenesis Imperfecta is a very hard diagnosis to receive (however, I will note that one of the sweetest, spunkiest 8 year olds I have ever had the pleasure of meeting has a type of OI, and man - her mama hit the jackpot when she got blessed with that angel). However some forms of OI are unfortunately lethal - and fractures in utero would be one of the primary indicators of whether your baby will have that condition. They looked at our xrays every two weeks to see if they could see signs of fractures with Asher - and since that was even a remote possibility, even though he did not show any signs of them during my ultrasounds - I chose a c-section in large part because I did not want to risk it. A vaginal birth is extremely dangerous and potentially life threatening for a baby with OI, as it puts a lot of pressure on the baby's bones as it is being delivered.

3. Ask whether the skull has an abnormal shape or appearance. Some lethal types of skeletal dysplasia, such as Thanatophoric Dysplasia, Type 2, have unique shaped skulls. Thanatophoric Dysplasia is the most common type of lethal skeletal dysplasia there is (however again, there are exceptions to every rule - and I happen to follow a wonderful teenage boy on Instagram who is living with Thanatophoric Dysplasia - and he will just cause your whole heart to melt). TD-2 typically presents with what they call a "cloverleaf skull". Similarly, Trisomy 18 often presents with a "strawberry shaped skull".

4. Ask whether the cranial sutures are still open. A baby's skull consists of the metopic suture, coronal sutures, sagittal suture, and lambdoid sutures (where all of the plates of the skull come together). If these sutures close too early, then the skull can't grow and expand like it typically would. The metopic suture is supposed to close between three and nine months of age. The coronal, sagittal, and lambdoid sutures are supposed to close between 22 and 39 months of age. With craniosynostosis, however, the sutures close too early and essentially turn into bone. While craniosynostosis is not a lethal trait on its own (many babies are born with it, sometimes as a completely isolated trait that is not associated with any underlying condition, and I know several beautiful children who have had and conquered craniosynostosis through surgery - and I may or may not stalk some of them on Instagram when I just need to put a big smile on my face), some lethal types of skeletal dysplasia can sometimes be associated with it (such as Thanatophoric Dysplasia).

5. Ask whether the bones have a typical degree of ossification. In short, this means are the bones as hard as they would expect them to be. When you are viewing bones on an ultrasound, the more ossified the bone is - the more visible and opaque the bone will appear. If a bone has not ossified properly, it will be much more translucent than the other bones on the screen. Some types of lethal skeletal dysplasias have a lethal degree of Hypophosphatasia (fancy word for a lack of bone mineralization). Of note though - there are plenty of people who live perfectly happy, typical lives with some degree of hypophosphatasia, and many types of skeletal dysplasia have varying degrees of it that impact certain bones (for example - as of his xrays at 18 months - you could still not see Asher's femoral heads on an xray - they have not ossified enough yet, and likely won't until he is at least 10 years old). It is the severe cases that would indicate a lethal type (such as perinatal lethal hypophosphatasia).

6. Ask what the TC/AC ratio is. This is the thoracic circumference‐to‐abdominal circumference ratio. I found this ratio used as a guideline for determining lethality during my research when I was pregnant with Asher. As of 30 weeks or so, I realized our doctor had never given us this ratio. So at our next ultrasound - I asked him what it was after he finished scanning me. He looked at me puzzled, and said "I don't know - lay back down and we will find out." So he rescanned Asher's thoracic circumference, pulled up the ratio - and was able to confirm that while Asher's TC/AC ratio was at the low end of normal, it was still within the normal range. This was one of the biggest sighs of relief my husband and I had been able to express in the previous 2 months. This meant that barring any unforseen circumstances, Asher would be able to breathe once he was born, and his lungs would have room to expand. Your specialist should be able to pull up the guidelines on what the normal range is for this ratio - and if they can't, I encourage you to find a new specialist.

7. Are all of the organs functioning properly. This one needs no explanation as to why it is a question that should be asked. Organ function is important for all babies. Many organ defects can be fixed these days with surgery after the baby is born, so if they do find something wrong - start asking what the game plan would be after birth.

I will end this note with the reminder that again, I am not a doctor. I am a mother who was given the worst news you can get during her pregnancy, who was told her baby was not going to survive, and who learned the essential need to push back and ask questions. These are the questions I asked repeatedly at every appointment and growth scan that we had, over the last 5 months of my pregnancy. While they couldn't give us an answer regarding exactly what condition Asher had at that time - these questions did provide us some answers, and quite a bit of comfort.

And while this list is not comprehensive - it gives you a good place to start with asking some of the questions that will help you get some definitive information about your pregnancy, and force the conversation out of the assumption arena.

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