Dunphy B C, Anderson-Sykes S, Brant R, Pattinson H A, Greene C A
Department of Obstetrics and Gynaecology, Foothills Hospital, Calgary, Alberta, Canada.
Hum Reprod. 1995 Jul;10(7):1825-7. doi: 10.1093/oxfordjournals.humrep.a136184.
The purpose of this study was to determine whether there is a seasonal variation in implantation and pregnancy rates following natural cycle replacement of cryopreserved embryos. A total of 321 consecutive cycles were analysed. There were 59 pregnancies (18.4%) and 48 live births or ongoing pregnancies (15.0%). Indicator variables for each month and variables representing temporal cycles of 12, 6, 4, 3 and 2 months were related to outcome. In addition, an analysis of periodicity was performed. No temporal, clinical or demographic variable was significantly related to pregnancy. This study indicated that there was no clear seasonal variation in the pregnancy rate following natural cycle replacement. However, the power of this study was low, and it was estimated that 963 subjects would be required to detect a 10% seasonal difference in pregnancy rates.
本研究的目的是确定在自然周期中解冻胚胎移植后着床率和妊娠率是否存在季节性变化。共分析了321个连续周期。有59例妊娠（18.4%），48例活产或持续妊娠（15.0%）。每个月的指标变量以及代表12、6、4、3和2个月时间周期的变量与结局相关。此外，还进行了周期性分析。没有时间、临床或人口统计学变量与妊娠有显著相关性。本研究表明，自然周期移植后的妊娠率没有明显的季节性变化。然而，本研究的效能较低，据估计需要963名受试者才能检测到妊娠率10%的季节性差异。
