A modified natural cycle results in higher live birth rate in vitrified-thawed embryo transfer for women with regular menstruation

Abstract

(2016) A modified natural cycle results in higher live birth rate in vitrified-thawed embryo transfer for women with regular menstruation, Systems Biology in Reproductive Medicine, 62:5, 335-342, DOI: 10.1080/19396368.2016 To link to this article: https://doi.org/10. 1080/19396368.2016 There is no consensus regimen for the optimal endometrial preparation for cryopreservation and vitrified-thawed embryo transfer cycles. This is largely caused by the lack of sufficient investigation and analyses on the respective pregnancy and perinatal outcomes by different regimens. This study aimed to compare both pregnancy and perinatal outcomes between the modified natural and artificial cycles in vitrified-thawed day three embryo transfer for women with regular menstruation. A total of 1,482 vitrified-thawed day three embryo transfer cycles were reviewed including 427 modified natural cycles (NC), 132 ovulation induction cycles (OC), 794 artificial cycles (AC), and 129 GnRH agonist artificial cycles (GAC). The primary outcome that was evaluated was live birth rate. The NC regimen demonstrated a higher rate of ongoing pregnancy (43.8% vs. 30.2%, P = 0.002) and a lower rate of late abortion (2.8% vs. 14.0%, P = 0.003) than the GAC regimen as well as a higher implantation rate (31.9% vs. 27.1%, P = 0.008) and live birth rate (43.1% vs. 34.1%, P = 0.002) than the AC regimen. A significantly higher peak endometrial thickness before transfer was observed in patients using the NC and GAC regimens (10.0 ± 1.7, 9.9 ± 2.4) compared to the AC regimens (9.2 ± 1.5, P = 0.000). Multivariate logistic regression showed that the NC protocol was associated with a higher live birth rate. There were no significant differences in rates of pregnancy complications, neonatal mortality, birth defects, mean birth weight, and other perinatal outcomes among the regimens. Modified natural cycle endometrial preparation regimen for vitrified-thawed day three embryo transfer is associated with superior live birth pregnancy outcomes compared to artificial cycles. Future studies are warranted to investigate the underlying biologic mechanisms of these findings.Abbreviations ART: assisted reproductive technology; BMI: body mass index; FET: frozen-thawed embryo transfer; HCG: human chorionic gonadotropin; IVF: in-vitro fertilization; IVF-ET: in-vitro fertilization and embryo transfer; OHSS: ovarian hyperstimulation syndrome; RCTs: randomized controlled trials ARTICLE HISTORY

Pregnancy Outcomes Following Letrozole Use in Frozen-thawed Embryo Transfer Cycles: A Systematic Review and Meta-analysis

“…BDR was not estimated as no birth defect was observed in either arm of the study. In the other 5 studies, HMG was not used in the letrozole arm [21,22,25,27,29]. When letrozole alone was compared with NC, the OR did not differ significantly for CPR (OR 1.30, 95 % CI: 0.68-2.52) (▶ Fig.…”

“…3), MR (OR 1.13, 95 % CI: 0.72-1.77), or BDR (OR 0.98, 95 % CI: 0.60-1.61) and there was no significant difference in WMD with regard to EMT (WMD − 0.36, 95 % CI: − 0.75 to 0.04) (▶ Table 2). Based on the single study by Guan et al, the OR for OPR was calculated to be 0.64 (95 % CI: 0.43-0.97) for the letrozole alone protocol, favouring NC [22].…”

“…5) and EMT (WMD − 0.24, 95 % CI: − 0.84 to 0.36) (▶ Table 2). One study reported BDR, but no birth defects were observed in the two groups (▶ Table 2) [22].…”

“…5) and EMT (WMD 0.02, 95 % CI: − 0.12-0.16) were found to be comparable for the letrozole plus HMG and the AC + GnRH-a groups (▶ Table 2). In another two ▶ studies, no HMG supplementation was used in the letrozole arm [21,22]. When letrozole alone was compared with AC + GnRH-a, the ORs for CPR and LBR were calculated to be 1.13 (95 % CI: 0.66-1.95) (▶ Fig.…”

Major Factors Affecting the Live Birth Rate After Frozen Embryo Transfer Among Young Women

“…Kawamura et al (26) reported a prospective trial showing that natural cycles had a higher LBR than cycles with hormone replacement treatment for FET, but the difference was not statistically significant. A retrospective analysis showed that the natural cycle for the cleavage-stage frozen embryo was associated with a higher LBR than the cycle with hormone replacement treatment (27). Therefore, whether the two different endometrial preparation methods for FET affect the FET outcome remains unclear.…”