When two brothers or sisters originate from the same fertilized egg cell, they are identical twins. In the womb, a fertilized egg cell quickly grows into a small lump of cells. Sometimes, that lump can split in two during the first week of pregnancy. Two babies start to grow in the womb who are genetically identical, and look so similar that sometimes only their parents can tell them apart.

You are pregnant with extra special identical twins, as your children share a placenta. The placenta ensures that the babies in the womb receive nutrition and oxygen from the mother. 

Sharing one placenta together can be difficult for a baby. The LUMC asks you and your twins to participate in medical scientific research into the health of children for whom pregnancy was not easy.