RELIEVING PRESSURE IN MY BABY’S OBSTRUCTED URINARY TRACT USING A FETAL BLADDER STENT
Thanks to Cook Medical, authors of the patient information leaflet for the Harrison Fetal Bladder Stent.
- Amniocentesis: A procedure in which a sample of the amniotic fluid is taken and studied.
- Amniotic sac: The space around your baby which is filled with fluid (amniotic fluid).
- Chorioamnionitis: An inflammation of the membrane surrounding your baby.
- Chorionic Villus Sampling (CVS): A procedure in which a sample of the tissue in the placenta, which is the membrane surrounding your baby, is taken and studied.
- Fetal Karyotype: A study of your baby’s chromosomes.
- Gestational Age: The time that has passed since your baby’s conception.
- Lower Obstructive Uropathy: A blockage in the urinary tract below the bladder.
- Maternal Sepsis: An infection in the mother.
- Open Fetal Surgery: The partial removal of a fetus from the uterus so surgery can be performed to correct a defect.
- Urinary Ascites: The leaking of urine into your baby’s abdomen.
- Urinary Tract: The system which removes urine from the body.
WHY IS THERE PRESSURE IN MY BABY’S URINARY TRACT?
Normally, your baby’s urine drains from the kidneys into the bladder. Then it drains through the urinary tract and into the amniotic sac. This is not happening with your baby. Your baby has a condition known as lower obstructive uropathy. This means that there is probably a blockage in your baby’s urinary tract. Your baby’s urine can’t flow into the amniotic sac. Pressure builds up behind this blockage. If left untreated, this pressure could cause damage to your baby’s kidneys. Because baby’s urine does not flow into the amniotic sac, there is too little amniotic fluid. The little amniotic fluid can lead to underdeveloped lungs, or lead to stillbirth because of umbilical cord compression. It could cause your baby to die shortly after being born because the lungs or the kidneys aren’t working. It could also cause severe physical deformities. A fetal bladder stent can decompress, or relieve the pressure in, your baby’s urinary tract. This happens because the urine drains through the stent from your baby’s bladder into your amniotic sac. It doesn’t have to go through your baby’s urinary tract so there is no pressure build-up.
ARE MY BABY AND MYSELF CANDIDATES FOR THIS PROCEDURE?
Your doctor can tell you if you and your baby could benefit from this procedure. You and your baby might be candidates for this procedure if:
- Your baby is 18 to 32 weeks gestational age and has a blocked urinary tract.
- Your baby shows no physical deformities under a detailed ultrasound.
- A study of your baby’s chromosomes, also called a fetal karyotype, shows no other serious defects.
WHEN IS THIS PROCEDURE USUALLY DONE?
The doctor can perform this procedure if a baby has reached at least 18 weeks but no older than 32 weeks gestational age. Since each case is different, your doctor will be able to give you more information about you and your baby.
WHAT WILL MY DOCTOR DO TO RELIEVE THE PRESSURE IN MY BABY’S URINARY TRACT?
You probably found out your baby might have an obstructed urinary tract during a routine ultrasound examination. You will need to have another detailed ultrasound examination. This is to make sure your baby has no physical problems.
Then, the doctor will perform a study of your baby’s chromosomes. In order to do this, the doctor will have to obtain a sample of your baby’s tissue to examine. The doctor does this in one of two ways.
The first is chorionic villus sampling or CVS. To perform a CVS, the doctor inserts a needle through your stomach wall into your uterus to obtain cells from the placenta. The second way is amniocentesis. To perform amniocentesis, the doctor inserts a needle through your abdomen and takes a sample of the amniotic fluid. These cells or fluid is studied to detect chromosomal problems in your baby (such as Down syndrome or Edward syndrome).
Finally, the doctor may sample your baby’s urine several times over a few days. The doctor inserts a needle through your abdomen and into your baby’s bladder. The doctor studies the urine to find out how well your baby’s kidneys are working. The baby’s urine sample can also be used to detect chromosomal problems in the baby,
The doctor will give you antibiotics to help protect you against infection. You will receive a local anaesthesia. The doctor may give you an additional sedative if it is necessary. Your doctor may also give your baby a sedative. The doctor does that if your baby is moving a lot or needs to be moved a great deal to find the best position.
The doctor may also perform an amnio-infusion. To do so, the doctor will infuse, or insert, fluid if there is not enough in the space between your baby and the wall of your uterus. If you need an amnio infusion, you will probably receive your antibiotics at the same time.
The doctor will place the fetal bladder stent under ultrasound. The doctor will insert a needle through your abdomen and into the baby’s bladder. This is the same as the urine sampling procedure, but will be done in theatre. An anaesthetist will give you sedatives through an intravenous line (“conscious sedation”).
If you did not need amnio-infusion, you will receive your antibiotics through this needle. The doctor will inject the antibiotics while the tip of the needle is in the amniotic space, just before it enters your baby’s bladder.
The fetal bladder stent then goes through the needle over a wire guide until one end of it curls up like a pigtail inside your baby’s bladder. The needle is pulled back, so that the other end curls up in the amniotic sac. The doctor then completely removes the needle and leaves the stent in place to drain.
The whole process should only take about half an hour. The doctor will want you to stay at least overnight in the hospital for observation to make sure that you and your baby are all right. During this time, the doctor will monitor your uterus to make whether contractions or irritability develops. If that happens, the doctor will give you medicine that helps to relax the uterus.
You will need to have your first ultrasound within 72 hours after the procedure, and then regularly to make sure that the stent is still in position and functioning well. Sometimes, through the baby’s movement or by grasping it, the stent can become dislodged or kinked. The stent could also become blocked. If this happens, the baby’s urine will longer be able to flow into the amniotic sac. The doctor will then have to replace the stent.
WHAT ARE THE RISKS ASSOCIATED WITH RELIEVING THE PRESSURE IN MY BABY’S URINARY TRACT USING THE HARRISON FETAL BLADDER STENT?
There are some possible risks involved with placement of the fetal bladder stent.
- You might develop chorioamnionitis, an inflammation of the fetal membrane. This may cause you to lose the fluid around your baby. It may cause infection in your baby or cause your baby to be stillborn. This inflammation can happen after any procedure, including placing a fetal bladder stent, in which a doctor places an instrument into your uterus during pregnancy.
- Your baby might have urinary ascites which is the leakage of urine into your baby’s abdomen. This happens when the baby’s bladder stretches too far. It can result from fetal stent placement. It usually goes away by itself following the placement of a fetal bladder stent.
- Placing the fetal bladder stent could cause you to go into preterm labour. It can happen after any surgery which goes into the uterus during pregnancy.
- The doctor places a needle through your abdomen and uterus and into your baby’s bladder. This makes a path for the stent. There might be some minor bleeding from your uterus or stomach wall and minor injury to your uterus caused by the passing of the needle. The bleeding will usually subside after a short time.
- You might have develop sepsis. This is an infection in you, not your baby. It can happen any time a doctor places an instrument into your uterus while you’re pregnant. This is why the doctor will give you antibiotics before and after placing the stent.
- The amniotic fluid may leak from the space between your baby and the wall of your uterus. This is another problem that can happen any time a doctor places an instrument into your uterus while you’re pregnant. It may go away by itself. However; there is no other way your doctor can treat the amniotic fluid leak.
- The needle could perforate, or make a hole in, your baby’s intestine or other organs. The doctor watches the procedure on ultrasound to minimize the risk of this happening.
- Placing a fetal bladder stent could cause you to abort or miscarry. This could happen if there is an inflammation of the fetal membranes.
Therefore, following decompression of the fetal urinary tract, IMMEDIATELY REPORT any pain, bleeding or vaginal fluid loss to your doctor. These warning signs should be evaluated promptly.
- After the stent placement, your baby might move and displace, or pull the stent out of the bladder. Your baby might grab the stent and pull it out. The stent might become kinked or blocked. If this happens, your doctor may need to place another stent in your baby’s bladder.
- On the longer term, your baby’s kidneys might be so damaged already, that kidney failure develops within months or years after birth.
ARE THERE ANY OTHER WAYS TO RELIEVE THE PRESSURE IN MY BABY’S BLADDER?
Your doctor can insert a needle into your baby’s bladder above the blockage and drain the urine to relieve the pressure. This has a short term benefit, and does not prevent damage to your baby’s kidneys and lungs.
Overseas, open fetal surgery has been performed. The doctor removes your baby from your uterus_ far enough to repair the blockage. After the repair, the doctor would place your baby back in your uterus to allow your pregnancy to continue.
DECIDING WHETHER OR NOT TO RELIEVE THE PRESSURE IN MY BABY’S URINARY TRACT
Deciding whether or not to relieve the pressure in your baby’s urinary tract is an important decision. The decision to have the placement of the fetal bladder stent or any other procedure to relieve the pressure is up to you and your partner. You do not have to have this procedure performed. You have read about the potential risks of the procedure. You must understand these risks. You should also know the potential risks of leaving this condition untreated. The pressure build-up could damage your baby’s lungs and kidneys. This could lead to physical deformity or to your baby’s death. ·
If you are thinking about having this procedure performed, you should discuss it with your doctor as soon as possible. Your doctor will be able to explain this procedure to you in more detail.
Before you make this, decision you must understand that relieving the pressure in your baby’s_ urinary tract will not correct the original defect. It will not get rid of the blockage in your baby’s urinary tract, It will allow urine to drain from your baby’s bladder without being backed up by the blockage. Your baby’s lungs and kidneys can continue to grow without pressure.
After your baby is born, a paediatric urologist will still need to correct the original defect.