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Cochrane Database of Systematic Reviews

Cycle regimens for frozen-thawed embryo transfer

Overview of attention for article published in Cochrane database of systematic reviews, July 2017
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  • In the top 25% of all research outputs scored by Altmetric
  • Good Attention Score compared to outputs of the same age (75th percentile)
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Mentioned by

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6 tweeters
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1 Facebook page
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1 Wikipedia page

Citations

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Readers on

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207 Mendeley
Title
Cycle regimens for frozen-thawed embryo transfer
Published in
Cochrane database of systematic reviews, July 2017
DOI 10.1002/14651858.cd003414.pub3
Pubmed ID
Authors

Tarek Ghobara, Tarek A Gelbaya, Reuben Olugbenga Ayeleke

Abstract

Among subfertile couples undergoing assisted reproductive technology (ART), pregnancy rates following frozen-thawed embryo transfer (FET) treatment cycles have historically been found to be lower than following embryo transfer undertaken two to five days following oocyte retrieval. Nevertheless, FET increases the cumulative pregnancy rate, reduces cost, is relatively simple to undertake and can be accomplished in a shorter time period than repeated in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) cycles with fresh embryo transfer. FET is performed using different cycle regimens: spontaneous ovulatory (natural) cycles; cycles in which the endometrium is artificially prepared by oestrogen and progesterone hormones, commonly known as hormone therapy (HT) FET cycles; and cycles in which ovulation is induced by drugs (ovulation induction FET cycles). HT can be used with or without a gonadotrophin releasing hormone agonist (GnRHa). This is an update of a Cochrane review; the first version was published in 2008. To compare the effectiveness and safety of natural cycle FET, HT cycle FET and ovulation induction cycle FET, and compare subtypes of these regimens. On 13 December 2016 we searched databases including Cochrane Gynaecology and Fertility's Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO and CINAHL. Other search sources were trials registers and reference lists of included studies. We included randomized controlled trials (RCTs) comparing the various cycle regimens and different methods used to prepare the endometrium during FET. We used standard methodological procedures recommended by Cochrane. Our primary outcomes were live birth rates and miscarriage. We included 18 RCTs comparing different cycle regimens for FET in 3815 women. The quality of the evidence was low or very low. The main limitations were failure to report important clinical outcomes, poor reporting of study methods and imprecision due to low event rates. We found no data specific to non-ovulatory women. 1. Natural cycle FET comparisons Natural cycle FET versus HT FETNo study reported live birth rates, miscarriage or ongoing pregnancy.There was no evidence of a difference in multiple pregnancy rates between women in natural cycles and those in HT FET cycle (odds ratio (OR) 2.48, 95% confidence interval (CI) 0.09 to 68.14, 1 RCT, n = 21, very low-quality evidence). Natural cycle FET versus HT plus GnRHa suppressionThere was no evidence of a difference in rates of live birth (OR 0.77, 95% CI 0.39 to 1.53, 1 RCT, n = 159, low-quality evidence) or multiple pregnancy (OR 0.58, 95% CI 0.13 to 2.50, 1 RCT, n = 159, low-quality evidence) between women who had natural cycle FET and those who had HT FET cycles with GnRHa suppression. No study reported miscarriage or ongoing pregnancy. Natural cycle FET versus modified natural cycle FET (human chorionic gonadotrophin (HCG) trigger)There was no evidence of a difference in rates of live birth (OR 0.55, 95% CI 0.16 to 1.93, 1 RCT, n = 60, very low-quality evidence) or miscarriage (OR 0.20, 95% CI 0.01 to 4.13, 1 RCT, n = 168, very low-quality evidence) between women in natural cycles and women in natural cycles with HCG trigger. However, very low-quality evidence suggested that women in natural cycles (without HCG trigger) may have higher ongoing pregnancy rates (OR 2.44, 95% CI 1.03 to 5.76, 1 RCT, n = 168). There were no data on multiple pregnancy. 2. Modified natural cycle FET comparisons Modified natural cycle FET (HCG trigger) versus HT FETThere was no evidence of a difference in rates of live birth (OR 1.34, 95% CI 0.88 to 2.05, 1 RCT, n = 959, low-quality evidence) or ongoing pregnancy (OR 1.21, 95% CI 0.80 to 1.83, 1 RCT, n = 959, low-quality evidence) between women in modified natural cycles and those who received HT. There were no data on miscarriage or multiple pregnancy. Modified natural cycle FET (HCG trigger) versus HT plus GnRHa suppressionThere was no evidence of a difference between the two groups in rates of live birth (OR 1.11, 95% CI 0.66 to 1.87, 1 RCT, n = 236, low-quality evidence) or miscarriage (OR 0.74, 95% CI 0.25 to 2.19, 1 RCT, n = 236, low-quality evidence) rates. There were no data on ongoing pregnancy or multiple pregnancy. 3. HT FET comparisons HT FET versus HT plus GnRHa suppressionHT alone was associated with a lower live birth rate than HT with GnRHa suppression (OR 0.10, 95% CI 0.04 to 0.30, 1 RCT, n = 75, low-quality evidence). There was no evidence of a difference between the groups in either miscarriage (OR 0.64, 95% CI 0.37 to 1.12, 6 RCTs, n = 991, I(2) = 0%, low-quality evidence) or ongoing pregnancy (OR 1.72, 95% CI 0.61 to 4.85, 1 RCT, n = 106, very low-quality evidence).There were no data on multiple pregnancy. 4. Comparison of subtypes of ovulation induction FET Human menopausal gonadotrophin(HMG) versus clomiphene plus HMG HMG alone was associated with a higher live birth rate than clomiphene combined with HMG (OR 2.49, 95% CI 1.07 to 5.80, 1 RCT, n = 209, very low-quality evidence). There was no evidence of a difference between the groups in either miscarriage (OR 1.33, 95% CI 0.35 to 5.09,1 RCT, n = 209, very low-quality evidence) or multiple pregnancy (OR 1.41, 95% CI 0.31 to 6.48, 1 RCT, n = 209, very low-quality evidence).There were no data on ongoing pregnancy. This review did not find sufficient evidence to support the use of one cycle regimen in preference to another in preparation for FET in subfertile women with regular ovulatory cycles. The most common modalities for FET are natural cycle with or without HCG trigger or endometrial preparation with HT, with or without GnRHa suppression. We identified only four direct comparisons of these two modalities and there was insufficient evidence to support the use of either one in preference to the other.

Twitter Demographics

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Mendeley readers

The data shown below were compiled from readership statistics for 207 Mendeley readers of this research output. Click here to see the associated Mendeley record.

Geographical breakdown

Country Count As %
Unknown 207 100%

Demographic breakdown

Readers by professional status Count As %
Researcher 30 14%
Student > Ph. D. Student 22 11%
Student > Bachelor 19 9%
Student > Master 18 9%
Other 16 8%
Other 37 18%
Unknown 65 31%
Readers by discipline Count As %
Medicine and Dentistry 67 32%
Biochemistry, Genetics and Molecular Biology 14 7%
Nursing and Health Professions 10 5%
Social Sciences 6 3%
Agricultural and Biological Sciences 5 2%
Other 19 9%
Unknown 86 42%

Attention Score in Context

This research output has an Altmetric Attention Score of 7. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 29 February 2020.
All research outputs
#3,238,499
of 17,100,199 outputs
Outputs from Cochrane database of systematic reviews
#5,891
of 11,628 outputs
Outputs of similar age
#67,023
of 272,667 outputs
Outputs of similar age from Cochrane database of systematic reviews
#157
of 246 outputs
Altmetric has tracked 17,100,199 research outputs across all sources so far. Compared to these this one has done well and is in the 80th percentile: it's in the top 25% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 11,628 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 24.6. This one is in the 49th percentile – i.e., 49% of its peers scored the same or lower than it.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 272,667 tracked outputs that were published within six weeks on either side of this one in any source. This one has done well, scoring higher than 75% of its contemporaries.
We're also able to compare this research output to 246 others from the same source and published within six weeks on either side of this one. This one is in the 36th percentile – i.e., 36% of its contemporaries scored the same or lower than it.