What is Twin to Twin
Transfusion Syndrome (TTTS)?
Twin to Twin Transfusion syndrome (TTTS) is a serious
complication of twin and triplet pregnancies that occurs in 10-15% of twin
pregnancies where the babies share the same placenta (the placenta is also known
as the afterbirth). Blood from one baby mixes with the blood of the other
through small blood vessels in the placenta.
If this blood is not shared equally between the babies one of them
becomes swollen with too much blood and the other becomes small and underfed
because of not enough blood.
When
and how is TTTS diagnosed?
TTTS is usually is diagnosed by
ultrasound between 16 and 22 weeks of pregnancy. In severe cases, one baby is
swollen (we call him or her “the recipient
twin”) and has a lot of amniotic fluid around it, while the other baby is
smaller (we call him or her “the donor twin”)
and has only a small amount of amniotic fluid around it. TTTS can be mild or
severe, depending upon how badly the babies are affected.
How
do you decide how bad the condition is?
Twin to Twin Transfusion Syndrome
has been divided into different “stages” to help to decide the most
appropriate treatment option for the level (or stage) of the condition.
-
Stage I: A small amount of amniotic
fluid (oligohydramnios) is found around the donor twin and a large amount of
amniotic fluid (polyhydramnios) is found around the recipient twin. At
this stage, we will usually recommend that the pregnancy is closely observed
for further deteriorations.
- Stage II:
Along with the description above, of the twins, the ultrasound is not able
to see the bladder in the donor twin. This would be an indication that
laser photocoagulation may be helpful.
- Stage III:
Everything in mentioned in stage II is present, but there is abnormal blood
flow in the umbilical cords of the twins. Laser photocoagulation is
recommended in this situation.
- Stage IV:
All of the above findings are present but in addition the recipient twin has
a swelling under the skin and appears to be in heart failure. Laser
photocoagulation may be attempted, but the chance of survival in this stage
is low.
- Stage V:
In addition to all the elements listed above, one of the twins has died.
Usually the donor twin is the twin to die first, but it can happen to
either.
What
will happen to the babies without treatment?
In severe cases, if TTTS is not treated,
both babies will die in the uterus. Those babies that survive the pregnancy have
a 1 in 4 risk of brain damage because of a lack of oxygen, blood and other
nutrients. The pregnancy may also be lost because the uterus gets over-stretched
from the extra fluid, which leads to early labor or miscarriage. In less severe
TTTS the outcomes are better, although the majority of pregnancies are still
lost.
What
are the options for treatment?
There are 3 main treatments offered for
TTTS. The choice depends on how bad the condition is and the wishes of the
parents. The choices are pregnancy termination, aggressive serial amnioreduction
and laser photocoagulation. All of these options are available to you and will
be discussed below. You are seeing us because your doctor believes that laser
photocoagulation may be helpful in your pregnancy.
What
is Laser Photocoagulation?
Laser photocoagulation is the use of
laser light to close the blood vessels on the surface of the placenta so that
the babies’ blood is no longer shared.
How
is it done?
The placenta is inspected with a very
thin telescope called a “fetoscope”. The fetoscope is placed into the uterus
through a tiny hole in the skin and under an anesthetic and so is not painful.
The telescope identifies the small connecting blood vessels and they are then
“coagulated” using laser light from a small fiber passed along it. The
surgery is done in an operating room and takes 30-60 minutes. The type of
anesthetic is decided between you, the surgeon and the anesthetist, but we
recommend an epidural. An epidural anesthetic will cause “numbness” from the
waist down and is used commonly for cesarean section. Laser photocoagulation is
a procedure newly available in the
Pacific Northwest
and all cases are operated on by a single physician,
Martin Walker
, M.D., a maternal-fetal medicine specialist who was trained in this
procedure in
London
,
England
.
What
are the results?
Five other institutions in the
United States
are currently able to use this treatment for TTTS. They have all had
encouraging results: in 80% of the cases, one twin survives; in 70% of the cases
both twins survive; and less than 5% of surviving twins have brain damage.
This compares favorably with the other treatments, where survival is lower and
the brain damage rate is higher.
A recent prospective randomized trial
comparing laser ablation to alternative therapies has demonstrated significantly
improved survival with a reduction in the rate of mental handicap in the
surviving babies.
What
are the risks?
A
- Infection
of the amniotic cavity may occur. Antibiotics are given in an attempt
to avoid this complication.
- Bleeding
in the mother and/or the babies, preventing the completion of the procedure.
Extremely small instruments (2-3 mm) are used to decrease the amount of
bleeding, however if the bleeding is very heavy, an abdominal skin incision
may be needed to stop it. In extreme cases, the bleeding could be so
heavy that the uterus must be permanently removed in order to control the
bleeding. In this situation, the mother would not be able to have any
more children. Severe, continuing bleeding could result in organ
damage and even death.
- Injury to
the mother or to the babies may occur from the procedure. Ultrasound is used
to watch the babies throughout the procedure as a guide to help to prevent
injury from occurring.
- Premature
labor or leakage of amniotic fluid may happen as a result of the
surgery. The very small size of the instruments helps to make this a lower
risk. In addition we give medications to relax the uterus and reduce the
chance of contractions.
- Miscarriage
or Fetal death may occur as a result of this procedure.
Who
is suitable for Laser Photocoagulation?
Pregnancies are considered appropriate for
laser photocoagulation in TTTS when they have the following:
- Single placenta (Monochorionic)
- Excess fluid (Polyhydramnios) present in
recipient twin
- Low fluid (Oligohydramnios) present in
donor twin
- Prominent bladder in the recipient and an
absent or small bladder in the donor
- Thin dividing membrane between the twins.
Patients with the following situations may
not be suitable for laser photocoagulation in TTTS:
- Pre-term labor with a short or open cervix
- Prior septostomy (procedure described
under alternative treatments)
- Abnormal genetic studies
- Ruptured membranes
- Infection of the amniotic fluid
(Chorioamnionitis).
What
happens when I come for the procedure?
You will be scheduled for a detailed
ultrasound examination of the twins when you arrive. The ultrasound will
look at the size of the twins, the amount of amniotic fluid surrounding each
twin, the placenta, the bladder of both twins and their heart function. The
blood flow in the umbilical cords will also be evaluated. This ultrasound will
take about an hour.
During and after the ultrasound, you will
meet with Dr. Walker to discuss the ultrasound exam along with the options for
treatment, including general prognosis and recommended follow-up care.
If laser photocoagulation is the treatment
choice selected, Melissa Dorn, the program coordinator, will discuss the details
of how to prepare for the surgery. Instructions on where and when to come
for the laser surgery will also be given. Melissa will also assist you with any
special needs you may have. You will be given two consent forms—one for
the hospital care and a second that will specifically describe the treatment
option of laser surgery. Please read these carefully. Melissa will then
take you to the admissions department to complete the pre-admission paperwork.
If needed, you may have a consultation with
the anesthetist before the procedure to determine your physical condition,
review your medical records and address any needs surrounding pain control.
Where
can I stay in
Kirkland
?
You should plan on spending a few days in the
Kirkland
area— one day for the detailed ultrasound exam and consultation and another
for the procedure. Depending on your situation, you may spend a day or
more in the hospital or you may be allowed to go home the same day as the
surgery. There are a number of close hotels and motels convenient to the
hospital.
Preparation
for Surgery
Before surgery, you should not eat or drink
anything for approximately 6 to 8 hours. This is to reduce the risk of
vomiting during the surgery. You might hear the phrase “NPO” in the
hospital—this simply means, nothing by mouth.
If your surgery is scheduled in the morning you should not eat or drink anything
after
midnight
. If your surgery is scheduled after
1pm
, you can have a regular dinner the night before surgery. After
midnight
, you can drink only water. After
7am
, you should not eat or drink anything. If you surgery is scheduled after
3pm
, you may drink water through the night and have clear liquids for breakfast.
Clear liquids are any item you can see through—such as tea, apple juice,
cranberry juice or jello. After
8am
, you should not eat or drink anything.
You should arrive 2 hours before your
surgery is scheduled to start. This time will be given to you by
Melissa Dorn
. When you arrive at the hospital, you should check in at the
Family
Maternity
Center
check-in desk located just inside the blue entrance. An intravenous line
(IV) will be inserted by a needle stick to give fluids and medication necessary
during the procedure. You may have a support person ( a friend or partner)
with you during this time, until you are taken back to the operating room. If
possible we will also allow one person to come into the operating room to sit
with you. Melissa and Dr Walker will be available to answer any questions
you may have. An ultrasound will be done before heading back to the
Operating Room to make sure that the babies’ heartbeats are still present.
You will then be taken to the operating room on by the nurse and helped up on to
the operating table. The anesthesiologist will then give you pain medication –
an epidural spinal or local anesthetic, depending on your situation. The
skin incisions made for the instruments are pretty small and usually require
only a band aid to cover them. The procedure will take between 40 minutes and an
hour and a half, but may take longer.
After
the Surgery
Following the procedure you will be taken
back to your room on the Family Maternity. The nurses there will be
monitoring your temperature, pulse, breathing and blood pressure as well as
monitoring your uterus for contractions.
Although pain should be minimal, medicine will be available if needed.
Antibiotics and medication to help relax the uterus and stop any contractions
will be given.
The morning after the procedure, an ultrasound will be done to see if there are
any changes in fluid volumes and blood flow in each baby.
Follow-up
Care
Your physician can resume your care for the
remainder of the pregnancy. Both you and your provider can contact us if
there are any questions or concerns.
We recommend weekly ultrasounds for the month following the procedure.
If everything looks normal, ultrasounds can then be done every two weeks, or as
suggested by your doctor.
We will continue to be interested in your progress and would like to receive
copies of your ultrasound examinations and any other relevant information.
Information regarding delivery will also been requested from your doctor.
We ask that your placenta be sent back to us for evaluation. This is
extremely important to evaluate our care and techniques. We will give you the
appropriate container and instructions.
We will contact you annually by telephone to see how your babies are doing for
at least 2 years.
How
can I get more information?
Because this is an uncommon
procedure, we have tried to keep this information sheet simple and
straightforward. If you would like more detailed information, research papers or
a copy of our protocol, please contact Melissa Dorn, Fetal Therapy Coordinator,
at 1-866-FET-SURG.
How
can I get a referral?
If you are interested in a
referral for laser photocoagulation, please contact
Melissa Dorn
RN, MN at (425) 899-3537 or toll free at 1-866-FET-SURG or email at: MLDorn@evergreenhealthcare.org.
Referral information will be discussed to determine if laser surgery is a good
option for you. Your provider can also choose to contact us directly to discuss
your particular case.
If it is determined that you are an
appropriate candidate, you will come to
Evergreen
Hospital
Medical
Center
’s Maternal Fetal Medicine clinic in
Kirkland
,
Washington
. Appointments will be made for ultrasound testing as well as consultation
with Dr. Walker. We will also schedule a surgery time prior to your
arrival. All prenatal records (including ultrasound reports) will be
requested. Providing your insurance information prior to any appointments
will help to identify if this procedure/testing will be covered by your
insurance. Approximately 80-85% of national insurance companies are
covering this procedure. All of the insurance companies in the
Seattle/Eastside area will cover this procedure at 85%.
What
are the alternative treatment options?
Serial amniocentesis is the removal of the
excessive fluid from around the recipient twin using a needle. This procedure
may temporarily restore the balance in the amniotic fluid volumes of both.
This technique may be useful for milder cases of TTTS, and is often
recommended in these cases, but is generally not effective for severe cases.
Generally, the need for many amniocentesis procedures has been shown to result
in a 40-60% survival rate of one of at least the twins, with approximately 25%
of the survivors mentally handicapped.
Septostomy is the creation of a hole in the
membrane between the babies using a needle. This causes fluid to move
towards the donor’s side and balance the fluid levels. Septostomy has
not been shown to be a successful therapy, especially in stage 2-5 cases and
may create complications such as amniotic bands and cord entanglement.
Umbilical cord ligation
is an technique that involves tying a knot around the cord of one of the
twins to stop its heart from beating, stopping the communication between the
fetuses. This is done using similar instruments to the fetoscope. This
procedure is used when one of the twins is so close to death that laser
ablation is not possible, and is done to protect the other twin from the
consequences of that death. The communication between the fetuses is
definitively ended, however, this eliminates the chance of survival for one of
the twins.
Given the poor prognosis of
this condition, when severe, and the need for complicated treatment plans,
before 24 weeks, TTTS may be treated with pregnancy termination, generally by
labor induction.
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