Some studies have reported improvements in fertilization or early embryo development. However, there is insufficient reliable evidence that it increases the chance of a live birth. Long-term safety, including outcomes for children, also remains uncertain.

No. Cytoplasmic transfer uses the patient’s own egg and retains its nuclear genetic material. However, donor mitochondria contain their own DNA, so mitochondrial DNA from the donor may also be present in a resulting child. In donor egg IVF, the donor’s egg is used.

No. ICSI introduces a sperm cell directly into an egg. Cytoplasmic transfer introduces donor cytoplasm. They are different procedures, although cytoplasmic transfer may be performed alongside ICSI.

Mitochondrial replacement techniques, such as spindle transfer or pronuclear transfer, move nuclear genetic material into a donor egg or fertilized donor egg whose nuclear material has been removed. They were developed to reduce the transmission of serious mitochondrial disease. Cytoplasmic transfer adds a small amount of donor cytoplasm to the patient’s egg.