Weiss N S, van Vliet M N, Limpens J, Hompes P G A, Lambalk C B, Mochtar M H, van der Veen F, Mol B W J, van Wely M
Center for Reproductive Medicine, Academic Medical Center, 1105 AZ Amsterdam, The Netherlands.
Center for Reproductive Medicine, VU Medical Center, Amsterdam, The Netherlands.
Hum Reprod. 2017 May 1;32(5):1009-1018. doi: 10.1093/humrep/dex035.
Is pre-ovulatory endometrial thickness (EMT) in women with unexplained subfertility undergoing IUI with ovarian stimulation (OS) associated with pregnancy chances?
We found no evidence for an association between EMT and pregnancy chances.
It has been suggested that OS with clomiphene citrate (CC) results in a lower EMT than with gonadotrophins or aromatase inhibitors, but the clinical consequences in terms of pregnancy are unclear.
STUDY DESIGN, SIZE, DURATION: We performed a systematic review and meta-analysis of studies comparing CC, gonadotrophins or aromatase inhibitors in an IUI program reporting on EMT and pregnancy rates in women with unexplained subfertility.
PARTICIPANTS/MATERIALS, SETTING, METHODS: We searched MEDLINE, EMBASE and the non-MEDLINE subset of PubMed from inception to 28th June 2016 and cross-checked references of relevant articles. Outcome measures were clinical pregnancy rate and mean pre-ovulatory EMT. We calculated mean differences (MD) with 95% CIs with a fixed effect model, and in case of heterogeneity with an I2 > 50% a random effect model. We performed a meta-regression analysis to determine if stimulating drugs interacted with the estimated effect of EMT.
Our search retrieved 1563 articles of which 23 were included, totaling 3846 women. There were 17 RCTs and 6 cohort studies. The average study quality was low and there was considerable to substantial statistical heterogeneity. Seven studies provided data on EMT in relation to pregnancy. There was no evidence of a difference in EMT between women who conceived and women that did not conceive (1525 women, MDrandom: 0.51 mm, 95% CI: -0.05 to 1.07). Women treated with CC had a significantly thinner EMT than women treated with gonadotrophins (two studies, MD: -0.33, 95% CI: -0.64 to -0.01). There was no evidence of a difference in EMT when comparing CC with letrozole (five studies, MDrandom: -0.84, 95% CI: -1.97 to 0.28). The combination of CC plus gonadotrophins resulted in a slightly thinner endometrium than letrozole (nine studies, MDrandom: -0.79, 95% CI: -1.37 to -0.20). Letrozole resulted in a thinner EMT than gonadotrophins (two studies, MDrandom: -1.31, 95% CI: -2.08 to -0.53).
LIMITATIONS, REASONS FOR CAUTION: The overall quality of the included studies was low to moderate. We found considerable to substantial heterogeneity in the comparisons, hampering firm conclusions.
We found no evidence for an association between EMT and pregnancy rates during IUI -OS. As a consequence, canceling IUI cycles because of a thin endometrial lining may negatively affect clinical care. Although we found some evidence for very small differences in EMT when comparing various drugs, we cannot make inferences on their effect on pregnancy chances since these differences may be coincidental.
STUDY FUNDING/COMPETING INTEREST(S): None.
N/A.
接受卵巢刺激（OS）的不明原因不孕症女性在进行宫内人工授精（IUI）时，排卵前子宫内膜厚度（EMT）与妊娠几率是否相关？
我们没有发现EMT与妊娠几率之间存在关联的证据。
有人提出，与促性腺激素或芳香化酶抑制剂相比，使用枸橼酸氯米芬（CC）进行卵巢刺激会导致EMT降低，但在妊娠方面的临床后果尚不清楚。
研究设计、规模、持续时间：我们对比较CC、促性腺激素或芳香化酶抑制剂在IUI方案中的研究进行了系统评价和荟萃分析，这些研究报告了不明原因不孕症女性的EMT和妊娠率。
参与者/材料、环境、方法：我们检索了MEDLINE、EMBASE和PubMed的非MEDLINE子集，检索时间从数据库创建到2016年6月28日，并交叉核对了相关文章的参考文献。观察指标为临床妊娠率和排卵前平均EMT。我们使用固定效应模型计算了95%置信区间（CI）的平均差异（MD），如果异质性I2>50%，则使用随机效应模型。我们进行了荟萃回归分析，以确定刺激药物是否与EMT的估计效应相互作用。
我们的检索共获得1563篇文章，其中23篇被纳入，共计3846名女性。有17项随机对照试验（RCT）和6项队列研究。平均研究质量较低，存在相当大到实质性的统计异质性。七项研究提供了与妊娠相关的EMT数据。在妊娠女性和未妊娠女性之间，没有证据表明EMT存在差异（1525名女性，随机MD：0.51mm，95%CI：-0.05至1.07）。接受CC治疗的女性的EMT明显比接受促性腺激素治疗的女性薄（两项研究，MD：-0.33，95%CI：-0.64至-0.01）。比较CC与来曲唑时，则没有证据表明EMT存在差异（五项研究，随机MD：-0.84，95%CI：-1.97至0.28）。CC加促性腺激素联合使用导致的子宫内膜比来曲唑略薄（九项研究，随机MD：-0.79，95%CI：-1.37至-0.20）。来曲唑导致的EMT比促性腺激素薄（两项研究，随机MD：-1.31，95%CI：-2.08至-0.53）。
局限性、谨慎原因：纳入研究的总体质量为低到中等。我们发现比较中存在相当大到实质性的异质性，妨碍了得出确凿的结论。
我们没有发现IUI-OS期间EMT与妊娠率之间存在关联的证据。因此，因子宫内膜薄而取消IUI周期可能会对临床护理产生负面影响。尽管我们发现比较各种药物时，EMT存在非常小的差异的一些证据，但我们无法推断它们对妊娠几率的影响，因为这些差异可能是偶然的。
研究资金/利益冲突：无。
无。
