There is a relationship between the success of two IVF transfers and one, and whether or not having non-invasive DNA at 13 weeks of pregnancy has an effect on the timing of the development of the abnormal embryo. If during the IVF transfer one embryo did not develop at the very beginning and just one embryo developed, in this case it is equivalent to a single pregnancy. It is possible to do non-invasive DNA directly at 13 weeks of conception. The other undeveloped fertilized egg will mostly be slowly absorbed by itself and will have no effect on the results of the non-invasive DNA test. If there are two IVF transplants, and one of them has a shorter period of fetal arrest, especially if the interval is less than 8 weeks, for example, fetal arrest at 10 weeks of pregnancy, then the non-invasive DNA test may be somewhat disturbed, because the free DNA fragments in the mother’s blood of the embryo with fetal arrest have not been completely ablated. Two IVF transplants, one successful, if you want to do non-invasive, you need to consult a professional fetal medicine experts, informed of the pros and cons, fully informed decision.