Objectives To study the incidence and potential causes of monozygotic twins after in vitro fertilization and embryo transfer （IVF-ET）. Methods A retrospective study was performed on women carrying monozygotic twins ...Objectives To study the incidence and potential causes of monozygotic twins after in vitro fertilization and embryo transfer （IVF-ET）. Methods A retrospective study was performed on women carrying monozygotic twins （MZTs） after conventional IVF-ET treatment at the Third Affiliated Hospital of Guangzhou Medical College in China from January 2003 to May 2009. The incidence and the miscarriage rate for MZTs following IVF-ET were examined iin relation to maternal age, duration of infertility, type and dose of hormone treatment, conventional IVF-ET cycles versus intracytoplasmic sperm injection （ICSI） cycles, the use of fresh or frozen-thawed embryos, and day （post-fertilization） of embryo transfer. Results Sixteen MZT pregnancies occurred in 2 161 patients （incidence of 0.74%）, of which 5 miscarried （31.25%）. No significant difference was found between MZT and non-MZT groups in terms of maternal age, duration of infertilit）, duration of gonadotropin （Gn） administration, dosage of Gn, number of oocytes retrieved, number of oocytes fertilized, or number of embryos transferred （P〉O.05）. The incidence of MZT was not statistically different between conventional IVF-ET cycles and ICSI cycles, between fresh embryos transfer cycles and frozen-thawed embryo cycles, or between different transfer days （P〉0.05）. Conclusion The incidence of MZTs following IVF-ET treatment greatly exceeds that observed following spontaneous conception. Intracytoplasmic sperm injection, frozenthawed procedures, and embryo transfer on different days were not correlated with an increased incidence of MZT pregnancies.展开更多
Blastocyst transfer is advocated to reduce the risk of multiple gestations in pregnancies by assisted reproduction. Nevertheless, there remains the rare inherit possibility of embryo splitting that can result in monoz...Blastocyst transfer is advocated to reduce the risk of multiple gestations in pregnancies by assisted reproduction. Nevertheless, there remains the rare inherit possibility of embryo splitting that can result in monozygotic twins leading to high-order multiples. Also, when a patient is found to have a higher gestation than the number of embryos transferred it calls into question the IVF facility’s competency and credibility. The case report presented such a rare phenomenon of embryo splitting and the clinical consequences precipitated from it. In the patient, two blastocysts were transferred 5 days after transvaginal oocyte retrieval. The pregnancy confirming hCG test did not predict high-order multiples in this case. Early ultrasonography documented trichorionic-quadramnionic gestation. Selective reduction of the monochorionic twins was done at 11 weeks. Dichorionic twin gestation continued uneventful until 22 weeks at which point the patient experienced preterm premature rupture of membranes with subsequent delivery. The pathology report confirmed trichorionic-quadramnionic gestation. The mode of splitting was different for the two embryos one leading to monozygotic dichorionic and the other to monozygotic monochorionic. Furthermore, the implantation was also apparently asynchronous with one implanted considerable later than the other. The first β-hCG value seemingly did not represent the entire initial implementation events otherwise the value would be higher carrying the early signal of high-order multiple.展开更多
文摘Objectives To study the incidence and potential causes of monozygotic twins after in vitro fertilization and embryo transfer （IVF-ET）. Methods A retrospective study was performed on women carrying monozygotic twins （MZTs） after conventional IVF-ET treatment at the Third Affiliated Hospital of Guangzhou Medical College in China from January 2003 to May 2009. The incidence and the miscarriage rate for MZTs following IVF-ET were examined iin relation to maternal age, duration of infertility, type and dose of hormone treatment, conventional IVF-ET cycles versus intracytoplasmic sperm injection （ICSI） cycles, the use of fresh or frozen-thawed embryos, and day （post-fertilization） of embryo transfer. Results Sixteen MZT pregnancies occurred in 2 161 patients （incidence of 0.74%）, of which 5 miscarried （31.25%）. No significant difference was found between MZT and non-MZT groups in terms of maternal age, duration of infertilit）, duration of gonadotropin （Gn） administration, dosage of Gn, number of oocytes retrieved, number of oocytes fertilized, or number of embryos transferred （P〉O.05）. The incidence of MZT was not statistically different between conventional IVF-ET cycles and ICSI cycles, between fresh embryos transfer cycles and frozen-thawed embryo cycles, or between different transfer days （P〉0.05）. Conclusion The incidence of MZTs following IVF-ET treatment greatly exceeds that observed following spontaneous conception. Intracytoplasmic sperm injection, frozenthawed procedures, and embryo transfer on different days were not correlated with an increased incidence of MZT pregnancies.
文摘Blastocyst transfer is advocated to reduce the risk of multiple gestations in pregnancies by assisted reproduction. Nevertheless, there remains the rare inherit possibility of embryo splitting that can result in monozygotic twins leading to high-order multiples. Also, when a patient is found to have a higher gestation than the number of embryos transferred it calls into question the IVF facility’s competency and credibility. The case report presented such a rare phenomenon of embryo splitting and the clinical consequences precipitated from it. In the patient, two blastocysts were transferred 5 days after transvaginal oocyte retrieval. The pregnancy confirming hCG test did not predict high-order multiples in this case. Early ultrasonography documented trichorionic-quadramnionic gestation. Selective reduction of the monochorionic twins was done at 11 weeks. Dichorionic twin gestation continued uneventful until 22 weeks at which point the patient experienced preterm premature rupture of membranes with subsequent delivery. The pathology report confirmed trichorionic-quadramnionic gestation. The mode of splitting was different for the two embryos one leading to monozygotic dichorionic and the other to monozygotic monochorionic. Furthermore, the implantation was also apparently asynchronous with one implanted considerable later than the other. The first β-hCG value seemingly did not represent the entire initial implementation events otherwise the value would be higher carrying the early signal of high-order multiple.
