This page contains general information about what congenital hydrocephalus (also known as fetal hydrocephalus) is, the diagnostic tests that are generally involved, the treatment options that are available and some general steps that you can take to make sure that you get the best information possible.
What is hydrocephalus?
Treatment Options?
We have our diagnosis, what do we do now?
What does this mean for my baby?
What is hydrocephalus?
OK, your doctor most likely covered this when they gave you the diagnosis. There were a few items that were missed during our initial discussions with the doctor though, most likely because he realized that we weren't soaking in anything other than the fact that there was a problem. So we'll cover the basics here. The short definition of hydrocephalus is as follows:
  • The brain is constantly producing fluid (known as cerebrospinal fluid or CSF) as part of its normal daily routine. Under normal circumstances, this fluid is drained from the brain into the spinal canal and is reabsorbed by the body, keeping the amount in the brain in a constant balance. When normal drainage does not occur, or for some reason the brain is producing too much CSF to be able to drain through normal means, the CSF builds up in the ventricles of the brain and causes pressure. This condition is known as hydrocephalus and, despite the fact that it is one of the single most common birth defects, most people have never heard of it. Some types always develop early in the pregnancy, but other types caused by bleeding or a tumor may not show up until later in the pregnancy.

That sounds pretty straightforward and isn't too hard to grasp. The problem comes in figuring out why the hydrocephalus is occuring. It turns out that a great number of things can cause that drainage to fail. Knowing something about why the fluid isn't draining can help in determining the outcome for the baby. We have found out that there are several causes of fetal (congenital) hydrocephalus and they are described below. To help you find some of the parts of the brain that are mentioned below, let's start out with a few pictures:

  • Aqueductal Stenosis - This is the most common form of fetal hydrocephalus, and it is the form that our baby has. There is a narrow channel which connects the third and fourth ventricles of the brain to allow CSF to drain. This channel is called the Aqueduct of Sylvius. When this aqueduct is blocked, or was never properly formed, the CSF cannot drain properly and this condition is called aqueductal stenosis. Blockage of the aqueduct can be caused by a malformed aqueduct, a tumor, swelling due to infection or intraventricular bleeding. This blockage results in the enlargement of the ventricles. This type is generally not caused by chromosomal abnormalities.
  • X-Linked Aqueductal Stenosis - I put this in its own category because while it is caused by a blockage in the aqueduct, the reasons and associated outcomes are quite different. In this case the cause is a mutation in the L1CAM gene on Xq28. No, I don't know exactly what that means either, but I do know that it means that in addition to the problems caused by the pressure, you can expect other types of problems as well that are caused by the gene mutation. Many (but not all) babies with this type have abducted thumbs. Abducted thumbs can often be seen on an ultrasound and the doctor will probably look for this indicator if a diagnosis of hydrocephalus has been made.

    X-Linked Aqueductal Stenosis is an x-linked recessive condition. There are two chromosomes that form a pair which determine gender in a person. For a boy the pair is made up of one X and one Y chromosome. For a girl the pair contains two X's. In order for a person to have a condition that is carried by a recessive chromosome, both chromosomes in the pair must have the genetic mutation that causes the condition. For this reason it is almost, but not quite, impossible for X-Linked Aqueductal Stenosis to be passed on to a girl. X-linked conditions are carried only on the X chromosome, and since boys only have one X chromosome, there is no second one to cancel it out. Therefore if a boy has the mutation in their X chromosome, they will have X-Linked Aqueductal Stenosis. A girl has two X chromosomes, which means that both would have to have the mutation for the girl to have X-Linked Aqueductal Stenosis. Since the mutation is extremely rare, the odds of having it in both the mother and father to pass down to the girl to form a pair of mutated chromosomes are very, very small.
  • Chiari Malformations - When the indented bony space at the lower rear of the skull, known as the posterior fossa, is smaller than normal, the cerebellum and brainstem can be pushed downward. The resulting pressure on the cerebellum can block the flow of cerebrospinal fluid causing hydrocephalus.

    Normally the cerebellum, fourth ventricle and brainstem sit just above the foramen magnum, which is the opening in the bottom of the skull where the spinal cord attaches to the brainstem. There are several different degrees of Chiari Malformations, depending on how far down the cerebellum has been pushed.
    • Chiari I - where just a portion of the cerebellum has been pushed down into the spinal canal. A Chiari I may not have any symptoms, or may cause problems with balance, dizziness, blurred vision, loss of muscle strength or spasticity.
    • Chiari II - In this type not only has the cerebellum been pushed downward into the spinal canal, but so has the fourth ventricle and the medulla (lower portion of the brainstem). This type is generally associated with spina bifida (myelomeningocele) which is a condition where the spinal cord does not close properly before birth.
    • Chiari III - Portions of the cerebellum and/or brainstem are pushed out through a hole in the back or neck. This type has a high fetal and infant mortality rate, and a high rate of severe complications in those that survive. The hole defect is closed with surgery and a shunt is placed for the hydrocephalus. This form is very rare.
    • Chiari IV - An extremely rare form where the cerebellum does not fully form, and which is rarely survived.

    For more information on Chiari malformations, please visit the following links:
    Neurosurgery Today
    Lucile Packard Children's Hospital
    Mayo Clinic

  • Dandy-Walker Malformation - Normally the cerebellum has two hemispheres which are separated by a narrow structure called the vermis. A Dandy-Walker malformation is characterised by a complete or partial absence of the vermis, along with a cyst located in the posterior fossa (the indentation at the base of the skull). The cyst communicates, or transfers CSF back and forth, with the fourth ventricle causing it to enlarge. There are other variations which can mimic the appearance of a Dandy-Walker malformation, but do not have the agenesis (absence) of the vermis of the cerebellum and the cyst does not open into the fourth ventricle. These variants are much more benign and have a better prognosis. The prognosis for a child with a true Dandy-Walker depends on the severity of the malformation and on whether or not there are other associated defects. Dandy-Walker malformations are often found with other problems, including agenesis of the corpus callosum and malformations of the face, limbs, fingers, toes and heart.

    For more information on Dandy-Walker Malformations, please visit the following links:
    National Institute of Health
    Healthlink Article

  • Trisomy Chromosomal Defects - Normally a human has 23 pairs of chromosomes, one set of 23 from the mother and one set of 23 from the father. The pairs are numbered from 1 to 23. Trisomy occurs when there are three chromosomes instead of just a pair of one of those numbered sets. The most common are Trisomy 13, Trisomy 18 and Trisomy 21 (Down Syndrome) meaning that the 13th, 18th or 21st pair has an extra chromosome. Trisomies 13 and 18 are generally considered to be "inconsistent with life", meaning that these children do not usually survive. I mention these only because the perinatologist who gave us our diagnosis started out by telling us that there was an excellent chance that this is what we were dealing with. I have no idea what he based that assumption on, but other parents have shared similar stories with us, that their initial diagnosis came with the news that it was likely that their child had one of these conditions and might very well not live. Based on this we, and other parents, told our other children that their little brother or sister may not live. We now know that while it is a possible diagnosis, it is not necessarily the likely diagnosis. An amnio will tell you for certain and these conditions are the ones that show up on the FISH test in the first few days, so don't worry about it until you get the results back.
  • Others - There are a number of other conditions that can also cause hydrocephalus or are associated with hydrocephalus. Tumors and hemorrages are common causes of hydrocephalus. Hydrocephalus is also sometime associated with agenesis of the corpus callosum - where the membrane that divides the two hemispheres of the brain does not form. Anencephaly - where the brain fails to form and fluid is all that is present is often incorrectly labeled as hydrocephalus. While sometimes the hydrocephalus can exist in isolation, it also often appears in conjuntion with a spectrum of other birth defects. There are just so many things that fall under the umbrella of hydrocephalus that you can't really start thinking about what the diagnosis of hydrocephalus means for your baby until you can determine something about the cause.
Treatment Options?
This is the part that really drove us crazy and was probably the single largest contributor to the big hills and valleys in the roller coaster. If you read nothing else on this website, read this section because it will save you the most pain.
  • In-utero surgery? Not in the USA! - There are a number of articles out there that are easily found on the web that describe in-utero surgery for hydrocephalus. These articles describe how shunting can be done while the baby is still in the womb and show great excitement about the hope that this surgery brings. The catch? You can't actually get this surgery anywhere in the USA. The most easily found articles are from Vanderbilt University like this one. I called them to see if we could get the surgery and the nurses told me that it couldn't be done anymore. I emailed one of the doctors that actually did the surgery in the past and he emailed me back saying that no, they don't do the surgery anymore. I spoke with doctors at the Children's Hospital of Philadelphia and the University of California San Francisco Children's Hospital, which also do fetal surgery and they both also said that the surgery was no longer available.

    Surprisingly, the reasons given for why this surgery had been stopped were vague. They mostly revolved around the idea that the risks were great and they couldn't really prove that the outcomes were any better with the surgery than they were without it. I have now read quite a few articles on the subject and I have found that most of the risk seems to be with infection and malfunction of the shunt. There is also the problem that hydrocephalus is often found with other conditions which don't always show up on ultrasound or MRI that can complicate the outcome. You can find out the results of the Vanderbilt study here.

    The subject is not entirely closed however. The research into prenatal surgery continues, although mostly in other countries. You can read about one recent case study in Saudi Arabia here. Dr. Sergio Cavalheiro of the Universidade Federal de São Paulo in Brazil has done a lot of research into this subject and has published some very promising results. We actually pursued the idea of having him do the surgery on our son while I was pregnant. I was able to contact him via email and at first he said that yes he could do the surgery and could I please send down my records. When I asked him where to send the records and how much would the surgery cost, he never replied. I'd like to think that he just went away on business somewhere for a few months and couldn't reply, but several attempts at email were ignored. I don't speak Portuguese, so I don't think I would have had much luck in contacting them via phone. A person with better language skills and less of a fear of going to a country where they don't speak the language for major/risky surgery might have better luck. You can read one of Dr. Cavalhiero's articles here.

  • Shunting shortly after birth - This is pretty much your only option and is likely to happen in all but the mildest cases. As described above, a shunt is basically a tube that is placed in affected ventricle of the brain that has a valve on it to make sure the fluid only flows out of the brain. The other end of the tube can be placed in various places such as the heart or lungs, but most often it is placed in the peritoneal cavity, which is the space surrounding the stomach. The peritoneal cavity is capable of absorbing large quantities of fluid and can easily soak up whatever the brain puts out. A nice picture showing how a shunt is placed can be found here.

    Once the shunt is in place the fluid begins to drain and the ventricles (and therefore the head) begin to shrink down to normal size. Our neurosurgeon says that this can be quite dramatic and in a severe case like ours it is possible that the head circumference can shrink by as much as 7 to 8 centimeters (2.75 to 3.15 inches) in the first week. This didn't happen for us as we only managed to go from 52 cm to 49.5 cm, but I have seen many babies where very large heads have been brought way down in size.
  • Deliver the baby early - I am updating this entry now that Owen is a year old and I am a year wiser. As you can read in our story, we were very gung-ho to have the birth as early as possible. We had read many articles about how babies born at 32 weeks almost always survive and it seemed that we should just get him out as soon as possible to put the shunt in and take off the pressure. We urged our doctors to consider a birth at 32 weeks, or at the very least at 34 weeks when the chances were even better. They all refused and said that we should have the birth at 36 weeks. We fought very hard against this. Now I am glad that the doctors stood their ground. As our neurosurgeon later told us, a normal baby that just has to survive might be able to do that. However, babies with hydrocephalus have to not only lie there and breathe, they have to survive brain surgery and general anesthesia within a day or two of birth. That is a whole different ball game and requires a much stronger baby.

    There is also the issue of the thickness of the skin. During the last few weeks in the womb, the baby spends a lot of its time building up the layer of fat under the skin which adds thickness and structure to the skin. Preemies are notorious for having thin skin, which mostly brings to mind a problem with keeping warm. What it means to a baby with hydrocephalus though, is that it might not be possible to place a shunt if the skin is too thin. Born at 35 weeks, (Owen's choice, not ours) Owen's skin was still quite thin and it was quite a surgical feat to get the shunt in. You could almost read the writing on the tubing through the skin. Below is a picture of Owen's shunt right after it was put in, you can see the white tubing through the skin:

    We had to be extremely careful that he didn't lay on it at all so that the skin didn't tear. They forced as many calories into him as they could for the first few weeks to build up the skin around that area. This all would cause us problems later because only the smallest tubing could be placed under his thin skin and it started clogging within two months. If there is not enough skin to put over the shunt, then an external ventricular drain has to be put in until a shunt can be placed. Owen had a programmable shunt put in and these are larger than the non-programmable kind. We were told before he was born that there was a chance that they would not be able to place a programmable if there wasn't enough skin. The programmable shunt has already saved him at least one and possibly two surgeries.

    In addition to these problems, you also increase the risk of causing the problem that you are trying to prevent: brain damage. If there are breathing difficulties which cause a lack of oxygen for any length of time, then brain damage can occur. The earlier the child is born, the greater the risk of this happening. You can also expect a longer stay in the hospital because of feeding issues. Every case is different, of course, but I now understand why it is that they were so adamant that we wait until at least 36 weeks. It's a balancing act between wanting to relieve the pressure and avoiding causing more problems.
  • Cord Blood therapy - I found out via a newsletter from the Cord Blood Registry (where we banked our daughter's cord blood) that some promising research is being done in using cord blood stem cells to treat pediatric brain damage. (See here for one of the case studies). Through the wonders of Google and the internet I was able to trace this research back to a Dr. Joanne Kurtzberg at Duke University Medical Center. I got in touch with Dr. Kurtzberg and she said that while the treatment had never been tried specifically for hydrocephalus, that there was no real risk involved in the treatment and there was sufficient enough promise in the treatment to make it worth the attempt. You can read more about this on the cord blood page.
  • Endoscopic Third Ventriculostomy (ETV) - This treatment option is generally only for cases of aqueductal stenosis where it is the third ventricle that fails to drain and it is also not generally successful in newborns. This is actually a very old treatment that involves putting a hole in the floor of the third ventricle to allow drainage without a shunt.  Newer techniques and technologies have greatly improved this option in recent years.  Our neurosurgeon says that this procedure is not generally successful in newborns because they heal too well and often the hole just closes up.  He did say that it will be an option when our baby is at least a year old.  It is not successful in all cases, but if it is then the baby will not have a lifelong dependency on shunts which can malfunction or become infected. You can find out more about this procedure here. It should be noted that this procedure also carries its own risks and is also something that must be managed throughout a lifetime of checkups.
We have our diagnosis, what do we do now?
This is the hard part. I'm assuming that if you are at home reading this then you are at least through the worst first few hours after diagnosis. Now what you need is a plan.
  • Get an amnio - If your personal beliefs allow for it, the first thing to do is to get an amnio done. We were dead set against an amnio when we got pregnant. We didn't want to introduce risk into the pregnancy just for "peace of mind". Well our perspective changed radically once we got a diagnosis like hydrocephalus. The amnio can rule out most chromosomal problems. Some of the conditions that can cause hydrocephalus are caused by chromosomal abnormalities such as Down Syndrome (also known as Trisomy 21) or Trisomy 13 or 18 which are generally fatal. Our doctor told us right away that these were a likely cause and what you really don't need is to worry about possibly immediately fatal things through the whole pregnancy. Get the amniocentesis done right away so that you can rule out (or deal with) these possibilities right away.

    I should include here a word of warning about what an amnio can and can't tell you. It can rule out maternal infections such as toxoplasmosis (that's the one you get from cleaning out the cat boxes). It can rule out most chromosomal abnormalities and you'll know definitively whether you have a boy or a girl. Finally it can detect abnormal levels of alpha-fetoprotein which could indicate that part of the baby's internal organs are being exposed to the amniotic fluid, such as in spina bifida.

    There are a few things that it can miss however. The most notable is that it can't detect X-Linked Aqueductal Stenosis. If you suspect that this might be the problem, there is a separate test for it. You have to specifically request an L1CAM gene test. This test is problematic however in that it takes about 10 weeks to come back from the lab and it is not 100% accurate (I can't remember the percentage anymore and I can't seem to find a reference on the web). The test is also very expensive and is not covered by most insurance. We opted not to bother since it would be more risk in another amnio, we'd worry for 10 weeks about it and it still wouldn't give us a 100% answer.
  • Get the FISH - FISH is an acronym for Fluorescence In Situ Hybridization. This lovely long set of useless words is all about getting some of your amnio results faster. A full amnio takes 7 to 14 days to come back and they are some of the longest days of your life. The FISH test returns in one to two days and is used to make certain that there are no extra chromosomes where there shouldn't be. Normal chromosomes come in pairs, one from the mother and one from the father. If you get an extra one you have one of the trisomy conditions (as shown above). These types of defects account for nearly 95% of all chromosomal abnormalities. It's not the full set of results, but it can rule out some of the biggies early in the process. Our insurance covered the FISH because of the abnormal ultrasound, but yours may not so I'd check into it, it's not cheap.
  • Get a fetal MRI done - If the amnio comes back clean and you don't therefore know the exact cause yet, get a fetal MRI done. Even in our little podunk town in southwest Virginia we have an imaging center that can do a fetal MRI. Your child's hydrocephalus was most likely diagnosed during an ultrasound. Ultrasounds are great for looking at bones and fluid, but they can't do much with soft tissue and the hydrocephalus is most likely a soft tissue problem (unless there is a tumor or such). In our case the MRI was able to see that there was no visible aqueduct so there was no way for the fluid to drain. You must keep in mind however, that a fetal brain is a very small thing and once the pressure has started to build all of the tissue gets squished so some of the smaller structures such as the corpus callosum are very difficult to see. It may not be possible to tell the difference between something that is not present and something that is squished. However it can give so much more detail than an ultrasound that even if it can't tell you the exact cause, it can probably serve to exclude certain others.
  • Get yourself a really good doctor - This is subjective of course, but it is very important. Our original OB immediately turned us over to a high risk fetal specialist as soon as the diagnosis was made. This was fine with us, that's why they have specialists. We were fine with our high risk guy until he started getting very vague about outcomes and flip-flopped on delivery dates until we were frustrated and confused. This is at a hospital with a level III NICU and excellent neonatal care. (Read our story for more details).

    We then went to a regional hospital at a mid-size university and that was a step up. We got some better answers (we understood that no one was going to tell us that the problem wasn't there, we just needed someone to be able to explain it to us in terms we could understand and to be able to come up with a plan). We were better there, but shortly after we found ourselves at Duke University Medical Center because of the cord blood treatments mentioned above. What a difference to be in a world class facility. The whole attitude was much different in terms of being aggressive about getting the shunt in early and trying even experimental (although low risk) procedures to at least try and help the baby.

    There are probably a lot of local/regional hospitals with great care, even for high risk babies, but in my book you should just start out by going to one of the best. It depends on where you live of course, but places like Duke, Vanderbilt, Children's Hospital of Philadelphia, UCSF Children's Hospital and those sorts are places are the place to start, not the place to end up. After your first conversation with them you'll know why. In our case even phone calls with them produced more information than we were getting locally. They know of more tests and they have a lot more experience with actual cases. Our doctors here were very kind, but they just didn't compare.
  • Wait - Now that you have the results of the ultrasound, amnio and MRI, you pretty much know everything there is to know. Depending on the type and whether or not the blockage is complete or partial, you will be able to watch the condition progress throughout the pregnancy but you aren't going to be able to do a thing about it. As a result this is one of the most frustrating diagnoses out there.
What does this mean for my baby?
This is the hardest one of all to predict and it is the one that a parent cares about the most. There are a few things to realize here that can help you keep you on the right path. The first is that as I mentioned above, hydrocephalus is an end result. There are many causes with vastly different ranges of outcomes. Unfortunately all of these causes have been thrown under the same umbrella with the diagnosis of "hydrocephalus". As a result all too often when you ask a perinatologist or other OB specialist about what the outcome is likely to be, you will get the grimmest picture possible. When you have Trisomy 13, aqueductal stenosis and late term IVH's being thrown into the same group, it's easy for the certainty of the poor outcome with Trisomy 13 to overshadow the possibility of better outcomes with the other types.

What you will need to do as a parent is to follow the steps I gave above in the "What do we do now" section. Until you have the answers to whether or not there are chromosomal problems and until you can at least narrow down the cause, you cannot even begin your search for possible outcomes. The results from those tests are vital to kicking the unapplicable causes out from under the umbrella so that you can just work with the causes that actually apply to your case. Problems with the cerebellum can cause different kinds of issues than the problems with the third ventricle. When chromosomal abnormalities are found, there are generally a reasonably well known set of issues that can come with those abnormalities.

Unfortunately even once you have all of your test results in hand, you will realize that the real answer is that no one will be able to tell you exactly what will happen with your baby unless you are facing a chromosomal abnormality that is severe enough to have a fairly predictable outcome. The brain is a strange thing and it is pretty much impossible to tell exactly what the outcome is going to be. In our case the tests showed aqueductal stenosis with no chromosomal abnormalities. After hearing many wildly ranging sets of possible outcomes for this type, our neurosurgeon at Duke finally said it to us in a way that we could put our heads around. During the pregnancy he said that at that point there is absolutely no way to tell if the outcome will be good or bad. He has seen babies whose ultrasounds looked just as grim as ours turn out just fine. He has also seen the cases with the same or better ultrasound presentations turn out poorly with little function. The whole point is that the ultrasounds tell you nothing other than the fact that the fluid is not draining. You can see the brain tissue being compressed against the side of skull, but you cannot in any way tell how much damage has been done.

Brain tissue is much like a sponge in that it can compress and expand as the pressure changes. The key is that once the shunt is put in and the pressure is relieved you can start to watch how much the brain tissue expands. If it expands to something nearing normal volume then there is an 80% chance of normal or near normal brain function. If the tissue has been severely damaged and does not expand, then the outcome will be severe. In some kids the brain just squishes and expands with no problem and in others the squishing does a lot of damage. There is no way to know in which category your child will be until the shunt is placed.

This doesn't make it any easier to handle the uncertainty and for those who might choose to terminate a pregnancy it gives you very little to work with to make a decision. It does, however, explain in no uncertain terms what you are dealing with.

The other thing to realize is that hydrocephalus is a long term problem. Shunting doesn't "cure" the the problem, it just manages it. Shunts have to be checked throughout your child's life as they can get infected, clogged or malfunction in other ways. Some kids get one shunt put in and it lasts them for years and years before they outgrow it and need a new one. Others seem to have infection after infection and just can't seem to get it to work. As with everything else with hydrocephalus, there is no way to know which category your child will fall into.

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