Vitrified-warmed blastocyst transfer on the 5th or 7th day of progesterone supplementation in an artificial cycle: a randomised controlled trial

Abstract

Prospective studies comparing different durations of progesterone supplementation before transfer of vitrified-warmed blastocysts in an artificial cycle are lacking. However, in oocyte donation programmes, the sporadic available evidence demonstrates considerable differences in clinical pregnancy rates according to the duration of progesterone administration. This randomised controlled trial (RCT), included 303 patients undergoing a frozen-thawed embryo transfer (FET) of one or two vitrified-warmed blastocyst(s) in an artificial cycle. Randomisation was performed when the endometrial thickness reached ≥7 mm after oestrogen supplementation. One hundred and fifty two patients in group A received 7 d of vaginal micronised progesterone tablets and 151 patients in group B received 5 d of micronised vaginal progesterone before FET. No differences were seen in clinical pregnancy rate between both groups: 42/152 (27.6%) in group A versus 49/151 (32.5%) in group B. Although no statistically significant difference was observed in clinical pregnancy rates, our study was powered to detect an absolute difference of 16%. In this regard, we cannot exclude that smaller, clinically relevant differences might exist and our study did not have the power to detect this. Patients were also not blinded for the intervention, causing a potential bias.

Chinese abstract

目前缺乏比较人工周期中玻璃化冻融囊胚移植前孕激素补充治疗的持续时间的前瞻性研究。然而, 在卵母细胞移植中, 鲜有证据表明, 孕激素补充治疗时间不同会引起临床妊娠率的显著差异。该随机对照试验（RCT）包括在303名在人工周期中进行1 ∼ 2个玻璃化冻融技术处理的冷冻囊胚解冻移植（FET）的患者。雌激素补充治疗后子宫内膜厚度达到7mm时进行随机化分组。在胚胎解冻移植前, 152名A组患者接受7天的微粉化黄体酮阴道上药, 151名B组患者接受5天的微粉化黄体酮阴道上药。两组间临床妊娠率：A组42/152（27.6%）与B组49/151（32.5%）差异无统计学意义。尽管临床妊娠率无显著统计学差异, 我们的研究仍发现了16%的绝对差异。我们不能排除这方面可能存在较小的临床相关差异, 但目前我们尚无能力来检测这一差异。患者也不是在被盲目的干预, 从而造成潜在偏倚。

Keywords:

• Blastocyst
• frozen embryo transfer
• implantation
• progesterone
• vitrification

Declaration of interest

The authors declare that they have no competing interests.

Ethics approval and consent to participate

The study protocol was approved by the Ethics Committee of UZ Brussel (B.U.N. 143201215471) and it was registered at www.clinicaltrials.gov (NCT02032797). All participating subjects gave written informed consent.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors.