Scientific and Medical Aspects of Human Reproductive Cloning (2002) / Chapter Skim
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4. Assisted Reproductive Technology
4. Assisted Reproductive Technology
Pages 61-73
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From page 61... ...
Of all the reported IVF cycles in the United States in 1998 using fresh eggs and embryos derived from the patient, 30.5% resulted in pregnan61
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From page 62... ...
Although efficiencies are not usually reported as the fraction of successful pregnancies per embryo transferred, 12% of embryos transferred in one study after preimplantation genetic diagnosis (POD) implanted successfully (yielding a success rate of 19.9% when measured in the usual terms of pregnancy per cycle)
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From page 63... ...
Other clinicians, after controlling for the effects of multiple births and parental age, have observed no increased risks after ICSI relative to other ART procedures when they scored for congenital malformations [16] (except an increased risk of a genital malformation termed hypospadias possibly related to paternal subfertility [16~)
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From page 64... ...
It differs from cloning in that the nucleus is derived from a normal egg rather than a diploid somatic cell, and the procedure is followed by fertilization by a normal haploid sperm. If oocyte nuclear transplantation were successful, however, it would suggest that a nuclear transplantation step itself, and the associated manipulations such as embryo culture, nuclear extraction, and nuclear injection do not preclude the birth of healthy babies.
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From page 65... ...
CAN THE SCREENING METHODS USED IN ART PROCEDURES BE USED TO PREVENT POTENTIAL SEVERE DEFECTS IN REPRODUCTIVELY CLONED HUMANS? Preimplantation genetic diagnosis Preimplantation genetic diagnosis is performed 2-4 days after fertilization on one or two cells removed from the developing preimplantation embryo [40-45~.
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From page 66... ...
As with Reimplantation genetic diagnosis, cloned embryos would need to be screened for expression levels and imprinting defects. The technical challenges here would be reduced in that more cells would be available for analysis, but they would be complicated because imprinting patterns differ between the embryo and the placenta.
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From page 67... ...
TO WHAT EXTENT ARE ART PROCEDURES REGULATED IN THE UNITED STATES? Reproductive cloning can be considered an assisted reproductive technique and thus may be subject to any regulations that cover existing ART procedures.
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From page 68... ...
That federal legislation requires ART clinics and embryo laboratories to report their pregnancy success rates and follow good laboratory practices [69~. These and other data covering United States ART clinics are published yearly under peer review in Fertility and Sterility [3; 70-75]
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From page 69... ...
3. Assisted reproductive technology in the United States and Canada: 1994 results generated from the American Society for Reproductive Medicine/Society for Assisted Reproductive Technology Registry.
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From page 70... ...
EXELER JR, DE GEYTER C, BEHRE HM, NIESCHLAG E, HORST J Chromosome abnormalities in 447 couples undergoing intracytoplasmic sperm injection prevalence, types, sex distribution and reproductive relevance.
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From page 71... ...
Mol Hum Reprod 1998 Mar, 4~3~:269-80.
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From page 72... ...
LIEBAERS I, VAN STEIRTEGHEM A Embryo implantation after biopsy of one or two cells from cleavage-stage embryos with a view to Reimplantation genetic diagnosis.
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From page 73... ...
74. Assisted reproductive technology in the United States and Canada: 1992 results generated from the American Fertility Society/Society for Assisted Reproductive Technology Registry.
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