By Emsie Martin
It’s been on your wish list for so long, but after three miscarriages you may feel you should perhaps stop hoping. You have a full-time stressful profession that takes a lot of your time. After months the doctor confirms that you are pregnant again and the sonar shows that it is definitely twins. You already begin to wonder how you are going to keep on working while handling two babies. A later sonar confirms that there is a shared placenta, which means it is TTTS.
But what is twin-to-twin transfusion syndrome (TTTS)?
According to information supplied by Dr Marshall, consultant obstetrician and gynaecologist, TTTS is a very rare and serious complication that affects 8−10% of identical twins.
In the case of identical twins with a shared placenta there is always a connection between their circulation. TTTS develops when there is an imbalance in their blood exchange. One twin, known as the donor, pumps some of his blood and nutrients through the placenta to the other twin, known as the recipient.
According to Dr Lou Pistorius, perinatologist at Mediclinic Panorama, the donor produces less amniotic fluid, which retards its growth. In the end the baby is attached to the side of the uterus because there is almost no amniotic fluid in its sac. It can even die in the womb because of insufficient nutrients or oxygen to stay alive.
The recipient, on the other hand, produces too much amniotic fluid. It can produce so much amniotic fluid that the mother’s abdomen suddenly becomes bigger, uncomfortable, and even painful. The large volume of amniotic fluid can also cause a miscarriage or premature birth. The recipient can also develop heart failure as a result of the overload of blood in circulation and may even die in the womb.
What causes TTTS?
In the case of twins with one placenta there are always connections in the circulation between the two. The donor gives more blood than is returned and later has too little blood in circulation, produces less urine and subsequently has less and less amniotic fluid, while the circulation of the recipient is overloaded and then produces more and more urine and amniotic fluid and then produces far too much amniotic fluid.
At what stage can TTTS be identified?
According to Dr Pistorius TTTS mostly develops between 16 and 24 weeks. A thorough sonar examination with good equipment is necessary to confirm TTTS. It could be difficult to see the membrane between the twins but can be seen near the donor twin. This member of the twins is often too small for the stage of the pregnancy and its mobility is limited because of the lack of amniotic fluid.
Options if TTTS is diagnosed?
In the past it was tried, without much success, to reduce the volume of amniotic fluid by means of medication, to suppress contractions, and to try and treat heart failure. With or without this medication less than 5% of twins with severe TTTS would have survived.
According to experts the options are as follows:
- To wait until something happens – the twins are monitored regularly to see if the TTTS will improve by itself, whether it becomes worse, and to find a solution. This is only of value at a very early stage.
- 2. Laser treatment – this procedure can be done between 16 and 26 weeks and will treat the cause of TTTS, i.e. the blood vessels that connect the exchange between the twins. This is done by inserting a small instrument, called a fetoscope, through the abdominal wall in the womb cavity. All vessels that connect the twins are cauterised by means of laser fibre. In this way the shared placenta is then artificially divided in two.
3.Reduction of amniotic fluid (amniodraining) – large volumes of amniotic fluid is drained from the amniotic sac of the recipient twin, which can help to extend the pregnancy, but draining the amniotic fluid does not change the underlying problem. If one of the twins should die, the survivor runs a big risk of permanent neurological damage because it loses a large volume of the blood in the circulation of the dead twin.
- Septostomy – a surgical method of making a small hole in the wall between the two. This allows the amniotic fluid to flow into the empty amniotic sac of the donor. This is also only a temporary solution. An additional problem is that an umbilical cord, arm or leg of a twin could become entangled in the opening between the two amniotic sacs, with disastrous consequences.
- 5. Selective feticide (fetus destruction) – the umbilical cord of one member of the twins can be tied off by means of a small instrument placed in the womb cavity. This means that one of the twins will die, but it gives the other twin a better chance of survival and to develop normally. In some cases this would be the best option.
Unfortunately the mother will at birth have to say goodbye to the baby that has already died.
- Termination of pregnancy at ±16 weeks
Treatment of TTTS
According to Dr Marshall it depends on the stage at which TTTS is diagnosed.
At stage I no treatment is necessary and there is a 50% chance that it will improve by itself.
At stages 2−4 there is a 90% chance of losing both babies and laser treatment to cauterise the connection on the placenta is the best option.
With laser there is also a 10−15% chance that you could go into labour or lose the babies.
According to experts laser is the best treatment for TTTS, but it has not yet been perfected.
At stage 5 it is too late to do anything and extensive counselling for the mother and planning of the delivery are called for.
Get a second opinion even today if you are pregnant with identical twins.
Sources
www.tttsfoundation.org (die VSA TTTS Foundation)
http://maternalfetal.co.za/pasiente/prosedures/ttslaser/
KENNERS: Dr. Marshal, voorheen konsultantverloskundige en ginekoloog by George Hospitaal en dr. Lou Pistorius, perinatoloog by Mediclinic Panorama.
Foto krediet: MART PRODUCTION | Pexels
