The zygote divides into 2, those 2 divide again to make 4 and so on, to create a mass of cells that eventually developes into a fetus, a baby and an adult. The process of cell division continues today and keeps you alive, because as some of your cells inevitably die there are plenty more new ones to keep you going.
Now it can happen that, at some time between the first and the fifteenth day, the developing zygote divides, but the two halves separate into two separate individuals - this is mono zygotic twinning. The two individuals develop into two babies - we call them Identical twins but they are quite distinct from each other in various subtle ways, and however alike they may look they are two different people with different lives.
( If you are wondering about the 15th day deadline, after that if the cell masses divide they form part of the sale whole and you end up with conjoined or parasitic twins)
The clearest sign that identical twins are on the way is ultrasound evidence of a shared amniotic sac
Some identical twins each have their own sac and umbilical cord, but they share a placenta. When a womb twin survivor of this type is born, the existence of their lost monozygotic twin can be confirmed if a single placenta has two cords attached, and a second sac, which may be empty, or may still contain the tiny body of the dead twin ( a foetus papyraceous)
Some other signs are:
- A twin stillborn or dying close to birth, who shared a sac or placenta with the survivor
- A Dermoid cyst
- A Foetus in foetu
- Cerebral palsy in the survivor
- Birth defects in survivor
- Split organs
- Congenital abnormality in the survivor
- Left handed
- A conjoined twin
- A parasisic twin
- One twin dying before or at birth as a result of twin-twin transfusion
The questionnaire has revealed the monozygotic womb twin survivors as a group and we have been making some comparisons between the two groups:
- Monozygotic (MZ) womb twin survivors
- Dizygotic (DZ) womb twin survivors
This week, I will be looking at the psychological character of the MZ womb twin survivor, which is quite distinct from the DZ survivor - whom I will describe in the coming week.
It is hard for some people to believe that the loss of a twin early in pregancy can have a profound psychological effect, and most of the people who do believe it are womb twin survivors themselves and have their own experience to draw on. However, this discovery that MZ and DZ womb twin survivor experience different psychological effects and are quite different from each other in character, may be the proof we need: there is something real here that is worth further examination by experts who are better qualified and resourced than I am to carry out research of this type. I am looking forward to the day when this is taken seriously at last.