Evidence map›Paper›PMID 33883950›Full record

ArticleInternational journal of women's health2021

The Effect of Additional Embryo Transfer on the Pregnancy Rate in Young Women Receiving in vitro Fertilization: A Natural Experiment Study.

Ran Kim, Seung-Ah Choe, Eun A Park, Myung Joo Kim, Young-Sang Kim, You Shin Kim

Open access · goldAbstract read
In one paragraph

Article in International journal of women's health, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact, top 96% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed, 0 citations in OpenAlex.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors at 2 institutions in 1 country.

Ran KimDepartment of Obstetrics and Gynecology, CHA Fertility Center Seoul Station, CHA University School of Medicine, Seoul, 04637, Korea.
Seung-Ah ChoeDepartment of Preventive Medicine, Korea University College of Medicine, Seoul, 02841, Korea.ORCID 0000-0001-6270-5020
Eun A ParkDepartment of Obstetrics and Gynecology, CHA Fertility Center Seoul Station, CHA University School of Medicine, Seoul, 04637, Korea.
Myung Joo KimDepartment of Obstetrics and Gynecology, CHA Fertility Center Seoul Station, CHA University School of Medicine, Seoul, 04637, Korea.
Young-Sang KimDepartment of Obstetrics and Gynecology, CHA Fertility Center Seoul Station, CHA University School of Medicine, Seoul, 04637, Korea.ORCID 0000-0002-1182-8167
You Shin KimDepartment of Obstetrics and Gynecology, CHA Fertility Center Seoul Station, CHA University School of Medicine, Seoul, 04637, Korea.
CHA University · KRKorea University · KR

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeTo assess the impact of additional embryo transfer (ET) on pregnancy in young women, we used a natural-experiment approach. PATIENTS AND

methodsThe design was based on the national policy of South Korea limiting the number of embryos transferred in vitro fertilization (IVF):≦2 embryos on day 2-4 or one on day 5-6 for patients aged <35, with one extra embryo allowed for patients aged ≥35. Using the data from 1909 ET cycles of 1287 women aged ≥34 and ≤35, we calculated adjusted risk ratios (RRs) for pregnancy.

resultsHalf of cycles were undertaken by women aged 35, and additional ET was performed in 68.7% of them. Intrauterine pregnancy (45.2% vs 51.3%) and multiple gestation (30.5% vs 6.9%) were more common in women aged 35 than in those aged 34. The RR for intrauterine pregnancy was 1.34 (95% confidence interval: 1.12-1.59) when comparing double ET to single ET in frozen day 5-6 cycles.

conclusionWe observed no evidence of a higher probability of pregnancy with additional ET in fresh or frozen day 3-4 ET, or in fresh day 5-6 ET of women aged 35. Additional ET may not increase the successful pregnancy rate in the 35-year-old group, unless it is a frozen day 5-6 ET cycle.

Indexed as

in vitro fertilizationmultiple pregnancypregnancy ratesingle embryo transfer

Identifiers

PMID33883950
PMCPMC8055292
OpenAlexW3153284335

What OpenQuestion holds

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LicenceCC BY-NC
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.