Intended parent The recipient has a minimal risk of contracting a transmittable disease. While the donor may test negative for HIV, such testing does not exclude the possibility that the donor has contracted HIV very recently, so the recipient faces a residual risk of exposure. In the US, the FDA requires full infectious disease testing no more than 30 days prior to retrieval and/or transfer. Many clinics require that donors be retested a few days prior to retrieval so the risk to the recipient is minimal. Intimate partners of both the egg donor and the recipient are also tested. The recipient must also trust that the medical history provided by the donor and her family is accurate. As American donors are paid thousands of dollars, such compensation may drive deceptive behaviors from donors. However, a full psychological evaluation is required by most IVF clinics, providing some evaluation of donor trustworthiness. In most cases, there is no ongoing relationship between the donor and recipient following the cycle. Both the donor and recipient agree in formal legal documents that the donation of the eggs is final at the time of retrieval, and typically both parties would like any "relationship" to conclude at that point; if they prefer continued contact, they may provide for that in the contract. Even if they prefer anonymity, however, it remains theoretically possible that in the future, some children may be able to identify their donor(s) using DNA databanks and/or registries (e.g., if the donor submits her DNA to a genealogy site and a child born from her donation later submits its DNA to the same site). Multiple birth is a common complication. Incidence of twin births is very high. At the present time, the American Society for Reproductive Medicine recommends that no more than 1 or 2 embryos be transferred in any given cycle. Remaining embryos are frozen, whether for future transfers if the first one fails, for siblings, or for eventual embryo donation. There appears to be a slightly higher risk of pregnancy-induced hypertension in pregnancies of egg donation. Fetus Pregnancies with egg donation are associated with a slightly increased risk of placental pathology. The local and systemic immunologic changes are also more pronounced than in natural pregnancies, so it has been suggested that the association is caused by reduced maternal immune tolerance towards the fetus, as the genetic similarity between the carrier and fetus from