Everyday Adventures: TTTS Awareness: What you need to know

December is TTTS (Twin-to-Twin Transfusion Syndrome) Awareness month, and today is World TTTS Awareness Day. TTTS is a disease of the placenta that can affect identical twins who share one placenta. The babies themselves are healthy, the issue is with the placenta and the circulation of blood between the babies and the placenta. (More about TTTS at the bottom of the post). I have shared our experience with TTTS with our boys previously. For today I want to focus on what you can do to help, and what you need to know if you or someone you know is pregnant.

An ultrasound is encouraged within the first three months to determine whether there are multiples, and if so, whether there is a shared placenta. TTTS only occurs in identical twins with a shared, monochorionic placenta. Monochorionic means one placenta and one outer sac, and there can be either one or two inner (amniotic) sacs. Twin pregnancies can be any of the following:

Dichorionic / diamniotic (two placentas, two amniotic sacs)
Monochorionic / diamniotic (one placenta, two amniotic sacs)
Monochorionic / monoamniotic (one placenta, one amniotic sac)

Once it is determined that there is only one placenta, extra precautions can be taken to monitor the pregnancy and watch for any potential issues.

From the TTTS Foundation website, here are the 15 most important questions for parents expecting twins to get answers to (the link has a more detailed explanation for each question):

Confirm at First Ultrasound (preferably by 10-16 weeks)
1. Is the placenta monochorionic?
2. Are the babies the same sex?
3. Can you see the dividing membrane?
4. Is the placenta anterior or posterior?
5. Do the cords have 3 vessels or 2?
6. Are the cords fully attached to the placenta?

Ask at Weekly Ultrasounds (Starting at Week 16 to Delivery)
7. What is the largest vertical pocket of fluid for each baby?
8. Can you see the bladder of the donor baby?
9. What are the weights of the babies in grams? (every 2-3 weeks)
10. Are the dopplers normal for both babies?
11. Is the heart of the recipient baby enlarged or thickened?
12. Does the recipient baby have hydrops?
13. What is the measurement of your cervix, is it long and
closed or thinning or dilated?
14. Is the smaller baby growing at the same rate?
15. What is the fundal height?

And for those who may not be familiar with TTTS, here is an overview, also from the TTTS Foundation website:

What is TTTS?
-Twin to Twin Transfusion Syndrome (TTTS) is a disease of the placenta (or afterbirth) that affects identical twin pregnancies.

-TTTS affects identical twins (or higher multiple gestations) who share a common monochorionic placenta.

-The shared placenta contains abnormal blood vessels which connect the umbilical cord and circulations of the twins.

-The common placenta may also be shared unequally by the twins

-The events in pregnancy that lead to TTTS are all random.

-TTTS is not hereditary or genetic, nor caused by anything the parents did or did not do.

-TTTS can happen to anyone.

And from the Fetal Hope Foundation website:

TTTS or Twin-to-Twin Transfusion Syndrome is a disease of the placenta. It affects pregnancies with monochorionic (shared placenta) multiples when blood passes disproportionately from one baby to the other through connecting blood vessels within their shared placenta. One baby, the recipient twin, gets too much blood overloading his or her cardiovascular system, and may die from heart failure. The other baby, the donor twin or stuck twin, does not get enough blood and may die from severe anemia. Left untreated, mortality rates near 100%.

The cause of TTTS is attributed to unbalanced flow of blood through vascular channels that connect the circulatory systems of each twin via the common placenta. The shunting of blood through the vascular communications leads to a net flow of blood from one twin (the donor) to the other twin (the recipient). The donor twin develops oligohydramnios (low amniotic fluid) and poor fetal growth, while the recipient twin develops polyhydramnios (excess amniotic fluid), heart failure, and hydrops. If left untreated, the pregnancy may be lost due to lack of blood getting to the smaller twin, fluid overload and heart failure in the larger twin, and/or preterm (early) labor leading to miscarriage of the entire pregnancy.

Some general treatment approaches consist of using laser energy to seal off the blood vessels that shunt blood between the fetuses. Because the surgical approach is via an operative fetoscope, there is minimal risk to the mother. Laser therapy for TTTS has been shown to provide improved pregnancy outcomes compared to alternative therapies. Although all treatment options should be discussed with your fetal surgeon.