Treatment outcomes of blastocysts thaw cycles, comparing the presence and absence of a corpus luteum: a systematic review and meta-analysis

Abstract

PurposeThis study aims to review the literature and perform a meta-analysis to determine if the presence of a corpus luteum has an impact on treatment outcomes in thaw cycles, where blastocyst embryos are transferred.MethodPUBMED, EMBASE, CENTRAL and CINAHL were searched for papers published between January 2017 and 27 July 2020. Additional articles were selected from the reference list of the results and previous reviews. Three reviewers independently reviewed and extracted data. The meta-analysis was conducted though RevMan V.5.4.1. Studies were quality assessed with the Cochrane risk of bias tool and the Newcastle-Ottawa Scale.ResultsNine publications were included for data extraction and subsequent meta-analysis. Two studies were randomised controlled trials, and seven were cohort studies. Subgroup analysis of the different study designs was performed. While the rates of positive human chorionic gonadotropin results (relative risk, RR 1.0, 95% CI 0.95 to 1.05) and clinical pregnancies (RR 1.06, 95% CI 0.96 to 1.18) were comparable between the two groups, the rates of live births were higher in thaw cycles with a corpus luteum (RR 1.14, 95% CI 1.06 to 1.22). Analysis of pregnancy losses demonstrated that both biochemical pregnancy (early miscarriage) (RR 0.71, 95% CI 0.62 to 0.82) and miscarriages (RR 0.72, 95% CI 0.62 to 0.83) were increased in cycles without a corpus luteum.ConclusionWhere clinically appropriate, the use of cycle types that have a functional corpus luteum should be favoured. There were several limitations to this study, including the quality of studies and the inherent bias of retrospective cohort studies. Further, high-quality research, particularly randomised controlled trials with blastocysts embryos, is required to further explore these findings.PROSPERO registration numberCRD42020209583.

The predictive value of uterine artery Doppler in the success rate of pregnancy from the first frozen embryo transfer during the implantation window

“…FET mainly applies to couples with a selective whole embryo freezing strategy, which carries the risks of fresh embryo transfer, refusal of fresh embryo transfer due to personal factors and preimplantation genetic test (PGT) of couples. Studies have indicated that FET can achieve the same or an even higher clinical pregnancy rate than fresh transfer, while reducing the risks of maternal pregnancy [ 4 – 6 ]. At present, the biochemical pregnancy rate of FET is approximately 15%, the abortion rate is approximately 20%, and the clinical live birth rate is 30–40% [ 2 , 3 , 6 ].…”

“…Studies have indicated that FET can achieve the same or an even higher clinical pregnancy rate than fresh transfer, while reducing the risks of maternal pregnancy [ 4 – 6 ]. At present, the biochemical pregnancy rate of FET is approximately 15%, the abortion rate is approximately 20%, and the clinical live birth rate is 30–40% [ 2 , 3 , 6 ]. Therefore, it is a hotpot of clinical research to constantly explore effective means of increasing the embryo implantation rate and the pregnancy rate, reducing the biochemical pregnancy rate and spontaneous abortion rate, and closely monitoring the risks of pregnancy.…”