January 13, 2011

Recurrent Pregnancy Loss: Genetic

Therapeutic options to treat genetically inherited thrombophilias such as Factor V Leiden or other genetic mutations that increase blood clotting include antithombotic medications such as low dose aspirin and low molecular weight heparin. These pregnancies are at high risk for complications later in pregnancy including intrauterine growth restriction and placental abruption and should be followed in consultation with a maternal fetal medicine specialist as needed.

The best treatment for parental chromosome rearrangements such as a balanced translocation, which occurs in 3% of couples with recurrent pregnancy loss, is preimplantation genetic diagnosis (PGD). This novel therapy involves analysis of the specific chromosome rearrangement in question. Analysis is performed on a cell biopsied from an early embryo (Day 3 after fertilization). This therapy of course would require in vitro fertilization (IVF) to create embryos for biopsy. An alternative therapy for an inborn chromosome abnormality in one of the partners of the recurrent aborting couple would be to use either donor egg or sperm, depending on the affected partner.

Since the majority of early pregnancy losses are chromosomally abnormal, it could be argued that the use of preimplantation genetic screening (PGS) in which IVF is performed followed by embryo biopsy on Day 3 following fertilization may be of benefit. Studies to date have not proven the efficacy of this new modality. Published studies to date, however, have not been able to test for all 23 pairs of chromosomes. Only within the past year has this technology to screen for all 23 pairs of chromosomes been available. It is also possible, should an abnormality be found in the embryo, to determine the origin of the abnormality that is either from the sperm, egg, or de novo from the embryo itself. A large multicenter trial is currently underway in Europe to determine the efficacy of PGS for couples suffering reproductive failure.

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Joseph A. Hill, III, M.D.

Joseph A. Hill, III, M.D. Board-Certified in Reproductive Endocrinology and Infertility