Reprod Biol Endocrin
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Reprod Biol Endocrin · Nov 2014
Comparative StudyThe presence of multiple gestational sacs confers a higher live birth rate in women with infertility who achieve a positive pregnancy test after fresh and frozen embryo transfer: a retrospective local cohort.
After spontaneous conception, the rate of miscarriage is more common in multiple rather than singleton pregnancies. However, the incidence of miscarriage is lower in in-vitro fertilization twin versus singleton pregnancies. Most patients have little understanding of pregnancy outcomes once they achieve a positive pregnancy test. This study investigated the relationship between multiple pregnancy and miscarriage in women with infertility after fresh and frozen embryo transfer. ⋯ Despite the many maternal and fetal risks of multiple pregnancies, patients who achieve a positive pregnancy test with fresh and frozen in-vitro fertilization and who have more than one pregnancy sac are more likely ultimately to deliver at least one baby. This finding is true of both fresh and frozen embryo transfer cycles. This pregnancy advantage is not seen in young patients and in patients using donor egg, and single embryo transfer maximizes birth outcomes.
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Reprod Biol Endocrin · Nov 2014
ReviewInternational regulatory landscape and integration of corrective genome editing into in vitro fertilization.
Genome editing technology, including zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and clustered regularly interspaced short palindromic repeat (CRISPR)/Cas, has enabled far more efficient genetic engineering even in non-human primates. This biotechnology is more likely to develop into medicine for preventing a genetic disease if corrective genome editing is integrated into assisted reproductive technology, represented by in vitro fertilization. ⋯ We herein examine current status of genome editing in mammalian embryonic stem cells and zygotes and discuss potential issues in the international regulatory landscape regarding human germline gene modification. Moreover, we address some ethical and social issues that would be raised when each country considers whether genome editing-mediated germline gene correction for preventive medicine should be permitted.