Evidence map›Paper›PMID 42174477›Full record

ArticleBMC pregnancy and childbirth2026

Comparison of the outcomes of cephalo-caudal to transverse uterine expansion in primary caesarean section: a study protocol for randomized controlled trial.

Suying Miao, Yanmei Zheng, Zixing Zhong, Suxiao Liu

Abstract readClinical Trial Protocol
In one paragraph

Article in BMC pregnancy and childbirth, 2026. 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
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.

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

4 authors.

Suying MiaoCenter for Reproductive Medicine, Department of Obstetrics, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, 310014, China.
Yanmei ZhengCenter for Reproductive Medicine, Department of Obstetrics, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, 310014, China.
Zixing Zhong *Center for Reproductive Medicine, Department of Obstetrics, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, 310014, China. zhongzixing@hmc.edu.cn.
Suxiao Liu *Center for Reproductive Medicine, Department of Obstetrics, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, 310014, China. zjuliusuxiao@163.com.

Funding

Zhejiang Provincial Project for Medical and Health Science 2025KY027Zhejiang Traditional Chinese Medicine Science and Technology Programme 2024ZL295
6 · The paper itself

Abstract

backgroundCaesarean delivery (CD) is the most common surgical procedure, accounting for nearly forty million childbirths annually. The technique of uterine incision expansion-blunt vertical versus transverse-significantly impacts intra-operative blood loss. This randomized controlled trial (RCT) aims to compare the two techniques to provide evidence-based guidance.

methodsThis single-center, double-blind RCT includes healthy pregnant women (aged 18-40 years, non-anemic) undergoing primary CD at Zhejiang Provincial People's Hospital. Participants are stratified by gestational age (≥ 37 + 0 vs. ≤36 + 6 weeks) and maternal age (≥ 35 vs. <35 years), then randomized 1:1 to cephalo-caudal (vertical) or transverse expansion. The primary outcome will be intra-operative blood loss, evaluated by two surgeons independently during the surgical procedure and further validated through difference between pre-operative and post-operative hemoglobin levels. Secondary outcomes will include lower uterine segment lacerations, additional sutures needed, and uterine vascular injury. The long-term outcome is the uterine niche formation via ultrasound one-year after childbirth. The minimal sample size will be 50 participants in each group to achieve 80% power (α = 0.05). Statistical analysis will be performed via SPSS (version 26.0) or GraphPad Prism (version 9.0). Ethical approval (No. QT2022315) was obtained from Zhejiang Provincial People's Hospital Ethics Board (January 17th, 2025). DISCUSSION: This RCT will compare the novel vertical and conventional horizontal uterine expansion techniques during CD. It will be stratified by maternal age, gestational age and only one surgeon to operate to reduce heterogeneity. The outcomes will include subjective and objective assessment. Despite a relatively small sample size, the study will generate evidence from a nation ranking the top in CD rates to address gaps in CD technique standardization.

conclusionBy comparing vertical and transverse uterine expansion, findings will directly inform strategies to minimize surgical blood loss and associated complications.

trial registrationChiCTR2200065203. Registered in August 2022, updated in January 2025.

Indexed as

Blood Loss, SurgicalCesarean SectionUterusAdolescentAdultDouble-Blind MethodFemaleGestational AgeHumansPregnancyRandomized Controlled Trials as TopicYoung AdultCaesarean sectionClinical protocolsObstetricsPregnancy

Identifiers

PMID42174477
PMCPMC13374066

What OpenQuestion holds

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LicenceCC BY-NC-ND
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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.