Twin fetal death
How often does fetal death of one twin occur?
Nobody knows for sure as figures from different countries; even different centres in the same country seem to differ widely. The lowest quoted figure is 0.5% (that is, one in 200 twin pregnancies), while the highest available claim a 5% rate, which is ten times the former. Either way, it is pretty uncommon. These figures do not include deaths occurring in twin-to-twin transfusion.
What are the consequences of fetal death in a twin pregnancy?
Apart from the inevitable parental distress over the loss of one of the babies, it may also have adverse effects on the surviving twin. The surviving twin may be found to have birth defects affecting the brain,, skin or kidneys. Various other organs may be affected. Long-term, the surviving twin may have cerebral palsy or mental retardation and learning difficulties. These complications are uncommon.
Is there anything that can be done to prevent these consequences for the surviving twin?
No. In most cases by the time the demise of one twin is discovered - which is often more than 24 hours later - the die is cast. If the surviving twin is to be affected, the damage is already done. Death of one twin in itself should therefore not be an indication for delivery unless there are other relevant obstetric indications. Either way, close monitoring of the surviving twin is necessary to ensure its continued well-being.
Can the dead twin cause infection in the womb if left there?
No. As long as the membranes around the baby are intact, there is no such risk. If the membranes are ruptured, prompt delivery is the only option.
Is death of one twin an indication for caesarean delivery?
No. Caesarean delivery will be considered for the usual obstetric indications. Death of one twin is not one of them.
If I have higher-order multiples such as quads, with evidence of increased risk of complications and unfavourable outcome, how can I be helped?
There is no question that both expectant mothers and obstetricians find the idea of killing one or more of the fetuses quite distressing. However, it is being increasingly acknowledged that this is sometimes a necessary evil. When the number of fetuses is more than four, severe prematurity is inevitable. Unfortunately, most do not survive and those that do are at increased risk of ending up with debilitating brain damage. This sort of situation calls for a hard-headed decision which may boil down to performing a fetal reduction. When this is opted for, the number left should not be more than three. It should be done early (at or before twenty weeks of gestation), to avoid complications.
The common method is to inject a chemical into the fetal heart, which will make it stop beating. The surviving twins or triplets will therefore be left with enough room to allow growth to a viable gestation. The injection is done under ultrasound guidance.
Can fetal reduction be offered for twins or triplets?
This is a matter of opinion. There is consensus however that there is no obstetric indication to perform fetal reduction in normal twins. The issue for triplets is less clear-cut.
Are twins at increased risk of chromosomal anomalies such as Down's syndrome?
The answer should be no. The fact that they are twins (or more) in itself is not a risk factor. However, if you are carrying non-identical twins, it means the chance of having an affected baby is doubled (and tripled for triplets, and so forth).
For identical twins, it is an all or nothing principle. If one is affected, the other one will be; conversely, if one is normal, the other one will also be normal. This is because they are genetically identical.