RESUMO
OBJECTIVE: To evaluate if the outcomes of IVF/ICSI in frozen-thawed embryo transfer and fresh embryo transfer cycles differ in relation to cleavage and blastocyst stages. METHODS: Retrospective cohort study to compare IVF/ICSI outcomes between fresh embryo transfer and frozen-thawed embryo transfer cycles, according to the stage of embryo development. Analysis was carried out on 443 consecutive embryo transfer cycles performed between January 1st and December 31st, 2014. Women aged up to 38 and submitted to embryo transfer cycles with fresh (n = 309) or frozen-thawed (n = 134) embryos at a private center for assistance in human reproduction were considered for analysis. Results in each group were stratified according to the stage of embryo development: cleavage stage and blastocyst stage. Main outcome measures were implantation rate, clinical pregnancy rate, ongoing pregnancy rate and live birth rate per cycle. RESULTS: In the fresh embryo transfer group, for cleavage stage versus blastocyst stage, respectively, implantation rates were 22% and 47% (p = 0.0005); clinical pregnancy rates were 34% and 64% (p = 0.0057); the ongoing pregnancy rates were 30% and 61% (p = 0.0046) and live birth rates were 28% and 55% (p = 0.0148). There were no significant differences in the rates between cleavage and blastocyst stages in the frozen-thawed group, neither between fresh and frozen-thawed cleavage embryo transfers nor between fresh and frozen-thawed blastocyst transfers. CONCLUSION: Our results confirm that blastocyst transfer is better than cleavage stage in fresh embryo transfer cycles. In frozen-thawed cycles, cleavage or blastocyst stages seem to offer similar reproductive outcomes.
Assuntos
Transferência Embrionária/métodos , Embrião de Mamíferos/citologia , Desenvolvimento Embrionário , Adulto , Implantação do Embrião , Feminino , Fertilização in vitro , Humanos , Gravidez , Resultado da Gravidez , Taxa de Gravidez , Estudos RetrospectivosRESUMO
Although the causality between Zika virus, microcephaly, and other central nervous system disorders has been taken for granted by the scientific community, many uncertainties remain. The gap of knowledge at the moment is large enough to remove part of the confidence physicians have on the advice given to patients - and infertile women in particular - on their reproductive plans. Pretreatment serologic screening is a possible strategy to offer more confidence for individuals choosing to bear children regardless of the Zika virus, but the tests currently available do not seem to be sufficiently adequate. Until now, there is no formal recommendation to avoid pregnancy solely because of the Zika virus outbreak, and the choice of becoming pregnant has been regarded as a personal decision to be made by each woman and her family.