Xiyuan Dong

The artificial cycle method improves the pregnancy outcome in frozen–thawed embryo transfer: a retrospective cohort study

Abstract The aim of this retrospective cohort study was to investigate which preparation method is optimal for frozen–thawed embryo transfer (FET) treatment. Analyses were performed on 3160 FET cycles, including 654 cycles with a natural cycle (NC) protocol and 2506 cycles with an artificial cycle (AC) protocol. The primary outcome measures were the clinical pregnancy rate (CPR) and the live birth rate (LBR) per transfer. The Student’s t-test, chi-square test and multiple logistic regression were used for statistical analysis. The CPR per transfer was 49.4% in the NC group and 58.6% in the AC group (OR = 1.270, 95% CI: 1.037–1.554). The LBR per transfer was 42.2% and 50.8% in the NC and AC groups, respectively (OR = 1.269, 95% CI: 1.037–1.552). Dividing the patients according to the type of transferred embryos, the CPR (67.3% versus 57.0%, p < 0.01) and LBR (58.8% versus 49.7%, p < 0.01) were higher after the AC protocol than after NC protocol in patients with blastocyst transfer. The NC and AC protocols yielded comparable CPR and LBR in the patients with cleavage embryo transfer. Our data indicate better pregnancy outcomes after the AC protocol than after the NC protocol. The AC protocol should be recommended in patients who were counseled before receiving FET treatment. Further studies are needed to confirm this finding. Chinese abstract 这项回顾性队列研究的目的是探讨冷冻解冻胚胎移植（frozen-thawed embryo transfer，FET）的最佳准备方法。对3160例FET周期进行分析，其中自然周期（natural cycle，NC）方案组654例，人工周期（artificial cycle，AC）方案组2506例。以每个周期的临床妊娠率（clinical pregnancy rate，CPR）和活产率（live birth rate，LBR）作为评价指标。使用t检验、卡方检验和多重logistic回归进行统计学分析。NC组每周期的CPR为49.4%，AC组每周期的CPR为58.6%（OR=1.270，95% CI：1.037-1,554）。NC组和AC组每周期的LBR分别为42.2%和50.8%（OR=1.269,95% CI: 1.037-1.552）。将患者按照移植的胚胎类型来分，其中行囊胚移植的患者，AC方案的CPR（67.3% Vs 57.0, p<0.01）和LBR(58.8% Vs 49.7%, p<0.01)均高于NC方案。而行卵裂期胚胎移植的患者，NC方案和AC方案具有相似的CPR和LBR。我们的数据表明AC方案的妊娠结局优于NC方案。对于接受FET治疗的患者推荐使用AC方案。这一结论需要进一步的研究来证实。

The criteria for optimal down-regulation with gonadotropin-releasing hormone-agonist: a retrospective cohort study

Abstract Objective: The objective of this study is to investigate whether the degree of down-regulation using GnRH-agonists is associated with pregnancy outcomes. Study design: This retrospective analysis was performed on 2708 cycles from 2514 patients undergoing down-regulation with the luteal phase long protocol. The serum oestradiol (E2D) and luteinising hormone (LHD) levels, the diameter of the largest follicle (DLFD) and the endometrial-thickness (ENTD) after down-regulation were used to evaluate the degree of down-regulation. One-way analysis of variance with the Bonferroni adjustment, the chi-square test and multivariate logistic regression analyses were used for the statistical analysis. Results: The cumulative clinical pregnancy rates (CCPR) and the cumulative live birth rates (CLBR) were higher in the cycles with E2D < 30 pg/ml (63.7%, OR = 1.405 (1.055–1.870) and 56.8%, OR = 1.372 (1.039–1.813)) and 30–55pg/ml (66.8%, OR = 1.439 (1.104–1.874) and 59.8%, OR = 1.397 (1.080–1.806)) than in those with E2D > 55 pg/ml (62.8% and 54.7%). There was a trend towards lower CCPRs and CLBRs in the cycles with DLFD > 10 mm or ENTD ≥ 6 mm; however, this difference was not significant. Conclusion: The degree of down-regulation is associated with ovarian response, pregnancy, and live birth. We propose the following criteria for optimal down-regulation: E2D 30-55 pg/ml, ENTD < 6 mm, and no apparent ovarian activity.