Fetal Anatomy Research Articles

Ultrasound Fetal Image Segmentation Techniques: A Review.

This paper reviews segmentation techniques for 2D ultrasound fetal images. Fetal anatomy measurements derived from the segmentation results are used to monitor the growth of the fetus. The segmentation of fetal ultrasound images is a difficult task due to inherent artifacts and degradation of image quality with gestational age. There are segmentation techniques for particular biological structures such as head, stomach, and femur. The whole fetal segmentation algorithms are only very few. This paper presents a review of these segmentation techniques and the metrics used to evaluate them are summarized.

Placental thickness on ultrasound and neonatal birthweight.

Objective To investigate the relationship between maximal placental thickness during routine anatomy scan and birthweight at delivery. Methods This retrospective descriptive study analyzed 200 term, singleton deliveries in 2016 at Penn State Hershey Medical Center. We measured maximal placental thickness in the sagittal plane from the ultrasound images of the placenta obtained at the 18-21-week fetal anatomy screen. The relationship between placental thickness and neonatal birthweight was assessed using Pearson's correlation coefficient (r) with 95% confidence interval (CI). Logistic regression was used to assess the association between placental thickness and secondary binary outcomes of neonatal intensive care unit (NICU) admission and poor Apgar scores. Two-sample t-tests, or exact Wilcoxon rank-sum test for non-normally distributed data, were used to assess for differences attributable to medical comorbidities (pre-gestational diabetes, gestational diabetes, chronic hypertension, gestational hypertension, preeclampsia and eclampsia). Results Placental thickness had a positive correlation with neonatal birthweight [r=0.18, 95% CI=(0.05, 0.32)]. The mean placental thickness measured 34.2±9.7 mm. The strength of the correlation remained similar when adjusting for gestational age (r=0.20) or excluding medical comorbidities (r=0.19). There was no association between placental thickness and NICU admission, Apgar scores <7 or medical comorbidities. Conclusion Our study demonstrated a positive correlation between sonographic placental thickness and birthweight. Future prospective studies are warranted in order to further investigate whether a clinically significant correlation exists while adjusting for more covariates.

Preliminary Experience Using Motion Compensated CINE Magnetic Resonance Imaging to Visualise Fetal Congenital Heart Disease.

Recent advances in cardiovascular magnetic resonance (CMR) imaging have facilitated CINE imaging of the fetal heart. In this work, a preliminary investigation of the utility of multislice CINE CMR for assessing fetal congenital heart disease is performed and compared with echocardiography. Multislice CINE CMR and echocardiography images were acquired in 25 pregnant women wherein the fetus had a suspected congenital heart defect based on routine obstetric ultrasound. Pathognomonic images were identified for each subject for qualitative comparison of CMR and echocardiography. Quantitative comparison of CMR and echocardiography was then performed by 2 reviewers using a binary scoring of 9 fetal cardiac anatomic features (identifiable/not-identifiable). Pathognomonic images demonstrated the ability of CMR to visualize a variety of congenital heart defects. Overall CMR was able to identify the majority of the 9 assessed fetal cardiac anatomic features (reviewer 1, 7.1±2.1; reviewer 2, 6.7±2.3). Although both reviewers identified more anatomic features with echocardiography (reviewer 1, 7.8±2.3; reviewer 2, 7.5±2.4; P=0.01), combining information from both modalities enabled identification of additional anatomic features across subjects (reviewer 1, 8.4±1.3; reviewer 2, 8.4±1.2). The primary limiting factor for CMR was inadequate coverage of the fetal cardiac anatomy or noncontiguous slices because of gross fetal movement. CINE CMR enables visualization of fetal congenital heart disease. This work demonstrates the potential of CMR for diagnosing congenital heart disease in utero in conjunction with echocardiography during late gestation.

Dynamic MRI of a Large Fetal Cardiac Mass

HomeRadiologyVol. 290, No. 2 PreviousNext Reviews and CommentaryFree AccessImages in RadiologyDynamic MRI of a Large Fetal Cardiac MassChristopher W. Roy, Christopher K. Macgowan Christopher W. Roy, Christopher K. Macgowan Author AffiliationsFrom the Department of Radiology, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Vaud, Switzerland (C.W.R.); Department of Medical Biophysics, University of Toronto, Toronto, Canada (C.K.M.); and Division of Translational Medicine, the Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 686 Bay St, Toronto, ON, Canada M5G 0A4 (C.K.M.).Address correspondence to C.K.M. (e-mail: [email protected]).Christopher W. RoyChristopher K. Macgowan Published Online:Nov 20 2018https://doi.org/10.1148/radiol.2018182025MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In A 29-year-old woman in her 21st week of pregnancy underwent fetal echocardiography, at which the fetus was diagnosed with a giant left ventricular rhabdomyoma in the setting of tuberous sclerosis complex (confirmed by genetic analysis TSC2 mutation at birth) (1,2). The left ventricular outflow tract and ventricular function were difficult to assess due to the size of the mass. As a result, fetal cardiac MRI with a 1.5-T imager was performed at 31 weeks, by using accelerated imaging (compressed sensing), translational motion correction, and data-derived retrospective gating, to produce motion-compensated high-spatial-resolution cine images of the fetal heart (Figure; Movie E1 [online]). Fetal cardiac MRI was used to identify the location of the mass in the left ventricle, confirm the patency of the left ventricular outflow tract, determine the fetal right and left ejection fractions (21% and 36%, respectively), and calculate the volume of the mass (35 mL). These images highlight the complementary role of fetal cardiac MRI in understanding complex fetal cardiac anatomy and function in the setting of an intracardiac mass.Coronal balanced steady-state free precession fetal cardiac MR images depict a large rhabdomyoma (M) in the left ventricle, the right ventricular outflow tract (RVOT, A), left ventricular outflow tract (LVOT, B), a pericardial effusion (P), and liver (L). Intracranial masses were also present on MR images of the brain (not shown).Download as PowerPointOpen in Image Viewer Get the Flash Player to see this video.Movie 1 Multisection multiphase motion-compensated coronal balanced steady-state free precession (bSSFP) cine images of a fetal heart with a giant cardiac rhabdomyoma in the left ventricle.Download Original Video (6.6 MB)Disclosures of Conflicts of Interest: C.W.R. disclosed no relevant relationships. C.K.M. disclosed no relevant relationships.C.K.M. supported by Canadian Institutes of Health Research (PJT 148505).

Fetal anatomy of the facial nerve trunk and its relationship with posterior auricular artery.

The aims of the study are to define anatomy of the facial nerve (FN) and its main trunks as well as their relationship with the posterior auricular artery in fetal period to evaluate the data for regional surgery in newborns and young infants. Formalin-fixed 34 fetuses from anatomy laboratory collection with a mean gestational age of 26.4 ± 4.6 (20-36) weeks were dissected. Parameters regarding the presence of major or minor trunks, width, length, branching pattern of FN were evaluated according to side, gender and trimester. The positional relationship of posterior auricular artery with the FN trunk was inspected. On all sides only the major trunk of the FN was detected. For length and width parameters, there was no statistically significant difference for side and gender except for trimester. Linear functions were found as 0.329 + 0.025×weeks for width and 5.264 + 0.185×weeks for length. There are statistically significant linear relationships between width and length of the FN trunk and week parameters as r = 0.507, p < 0.001 and r = 0.484, p < 0.001, respectively. Posterior auricular artery crossed FN trunk laterally in 42 of 53 sides, medially in 9 sides while it was puncturing it proximally in 2 sides. In all cases, it was in close contact to the FN trunk. FN trunk showed bifurcation in 82% and trifurcation in 18%. Dimensions of FN trunk, growth ratio and linear functions can be beneficial in understanding the fetal growth of FN trunk and its usage for grafts. Data about the relationship of the posterior auricular artery with FN trunk may be crucial in avoiding iatrogenic injuries during surgery in early ages.

Segmentation and classification in MRI and US fetal imaging: Recent trends and future prospects

Fetal imaging is a burgeoning topic. New advancements in both magnetic resonance imaging and (3D) ultrasound currently allow doctors to diagnose fetal structural abnormalities such as those involved in twin-to-twin transfusion syndrome, gestational diabetes mellitus, pulmonary sequestration and hypoplasia, congenital heart disease, diaphragmatic hernia, ventriculomegaly, etc. Considering the continued breakthroughs in utero image analysis and (3D) reconstruction models, it is now possible to gain more insight into the ongoing development of the fetus. Best prenatal diagnosis performances rely on the conscious preparation of the clinicians in terms of fetal anatomy knowledge. Therefore, fetal imaging will likely span and increase its prevalence in the forthcoming years. This review covers state-of-the-art segmentation and classification methodologies for the whole fetus and, more specifically, the fetal brain, lungs, liver, heart and placenta in magnetic resonance imaging and (3D) ultrasound for the first time. Potential applications of the aforementioned methods into clinical settings are also inspected. Finally, improvements in existing approaches as well as most promising avenues to new areas of research are briefly outlined.

58th Annual Meeting of the Japanese Teratology Society: Congenital anomalies as variants

58th Annual Meeting of the Japanese Teratology Society: Congenital anomalies as variants

AIUM-ACR-ACOG-SMFM-SRU Practice Parameter for the Performance of Standard Diagnostic Obstetric Ultrasound Examinations.

AIUM-ACR-ACOG-SMFM-SRU Practice Parameter for the Performance of Standard Diagnostic Obstetric Ultrasound Examinations.

EP08.06: Clinical implementation of 5DCNS+ tool: prospective data of &gt;1.100 consecutive pregnancies

To evaluate reliability and diagnostic value of a semiautomised volumetric approach (5DCNS+) in terms of detailed assessment of the fetal CNS anatomy in normal and abnormal fetuses in a clinical setting. In this prospective study a total of 1.114 singleton pregnancies referred for targeted anatomic survey (including fetal neurosonogram) were enrolled. 3D volume data were acquired and post-processed using the 5DCNS+ software. All resliced volumes were categorised into 3 groups and scored in terms of adequately displayed diagnostic planes and the need for manual adjustment. In addition, 53 cases with major CNS anomalies were separately assessed and compared to matched controls. A total 1.093 cases met the inclusion criteria. Mean gestational age (GA) was 23.5 wks (16.6-36.7). By categorising into 3 groups (group I – GA >14 to 19.9 wks; group II 20.0 to 25.9 wks and group III ≥26.0 weeks) we were able to show that in group II the semiautomatic approach performed best (image reconstruction/adjustment; p=0.0003). Logistic regression model identified BMI and GA as dependent variables. Volume analysis using 5DCNS+ is feasible even in abnormal cases, although there were a significantly higher need for volume adjustment (p<0.001) and volumes to be acquired (p<0.001). In fact, the 5DCNS+ tool facilitates reliable assessment of fetal CNS anatomy even in case of altered cerebral anatomy. In 75 % of cases ≤ 2 manual adjustments were needed. In its present form it might rather be of value for diagnosis confirmation for professionals than for the inexperienced examiners. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

P05.08: A study of postmortem three‐dimensional ultrasonography with novel rendering to assess fetal anatomy

P05.08: A study of postmortem three‐dimensional ultrasonography with novel rendering to assess fetal anatomy

Early fetal morphological evaluation (11–13 + 6 weeks) accomplished exclusively by transabdominal imaging and following routine midtrimester fetal ultrasound scan recommendations. Since when can it be performed?

Objectives: To establish the best timing for the realization of first-trimester-morphologic-evaluation, following routine midtrimester fetal-ultrasound-scan-recommendations (RFUSR), by performing exclusive transabdominal exploration, and to determine the sensitivity of the mentioned scan for diagnosis of major structural abnormalities.Method: Prospective observational study with 512 pregnant women with singleton gestations (438 low-risk, 74 high-risk) was conducted. Early fetal morphological evaluation (EFME) is performed in line with RFUSR (18–22 weeks) (ISUOG 2010) and a check-list structured evaluation was followed, between 11–13 + 6 weeks. Its performance is assessed in the correct identification of normal fetal anatomy, and its effectiveness in the detection of structural defectsResults: Five hundred and four pregnant women were evaluated, of which, 58.3% EFME are considered complete fetal anatomical surveys. Complete fetal anatomical surveys scans rise from 23.1% at 11–11 + 6 weeks to 63.8% at 13 + 3–13 weeks, with a clear turning point at 12 + 6–13 + 3 weeks (63.8%) (p < .05). From 12 + 6–13 + 3 weeks only renal (26.3%) and cardiac assessments (31.6%) present an inconclusive evaluation greater than 20%. Body mass index (23.9 versus 29.8) and estimated fetal weight (63 versus 86.7 g) influence EMFE’s ability of identifying fetal structures (p < .05). EMFE presents sensitivity for the identification of structural malformations of 83.3% (20/24).Conclusions: From 12 + 6 weeks of gestation onwards, a complete fetal morphological evaluation can be performed in 63.8% of cases following the routine midtrimester fetal ultrasound scan recommendations (ISUOG’s 20 weeks scan).

11–13+6 haftada fetal anatomiyi ne kadar değerlendirebiliriz?

11–13+6 haftada fetal anatomiyi ne kadar değerlendirebiliriz?

First Trimester Screening for Fetal Aneuploidies Using Placental Growth Factor: The Great Obstetrical Syndrome (GOS) Study

ObjectiveThis study sought to estimate the ability of first trimester maternal serum placental growth factor (PlGF) to identify fetal aneuploidies. MethodsA prospective cohort study of singleton pregnancy at 11 to 13 weeks was conducted. Maternal serum PlGF concentration was measured using BRAHMS PlGF plus KRYPTOR automated assays (Thermo Scientific BRAHMS, Hennigsdorf, Germany). PlGF and nuchal translucency were log-transformed and reported as multiples of the median (MoM) adjusted for crown-rump length. Detection rates were calculated using receiver-operator characteristic curves. ResultsThe study observed 21 cases of fetal aneuploidies (0.4%) out of 4765 participants. Trisomy 21 (13 cases; 0.85 MoM; interquartile range [IQR] 0.80–0.93), trisomy 18 (two cases; 0.77 MoM; IQR 0.66–0.87) and trisomy 13 (two cases; 0.68 MoM; IQR 0.61–0.75) were associated with low PlGF concentrations. The low PlGF values observed in the cases of monosomy X (two cases; 0.85 MoM; IQR 0.82–0.88, P = 0.05), triploidy (0.78 MoM, P = 0.11), and 47,XX,i(22)(p10) (0.18 MoM, P = 0.08) were not statistically different from the controls. A model including maternal age, nuchal translucency, and PlGF could have identified all (95% CI 83%–100%) cases of trisomy 21 and six of the other fetal aneuploidies (75%) at a false-positive rate of 9%. ConclusionLow first trimester PlGF is associated with an increased risk of fetal aneuploidy. PlGF combined with first trimester ultrasound (nuchal translucency, uterine artery Doppler, and early fetal anatomy) could identify not only women at high risk for preeclampsia, but also fetuses at high risk of aneuploidy for optimal further testing (non-invasive testing for common aneuploidy screening or chorionic villus sampling for full screening and diagnosis).

Application of First Trimester Screening in the Prognostication of Small for Gestational Age

Background: Fetal growth restriction is defined as the failure of the fetus to achieve its full growth potential. The present study aimed to investigate the application of first trimester screening in the prediction of small for gestational age (SGA).Methods: This cohort study was conducted on the consecutive and unselected women with singleton pregnancies undergoing routine first-trimester examinations in a health center affiliated to Neyshabur University of Medical Sciences in Razavi Khorasan Iran during February 2014-March 2016. Subjects received a first-trimester visit by a physician, which included the entry of basic maternal characteristics, medical history, measurement of maternal weight and height, ultrasound examination for fetal anatomy, and measurement of crown-rump length to assess gestational age.Results: SGA was significantly correlated with maternal age, parity, and body mass index. Furthermore, a significant association was observed between SGA and smoking habits in the mothers.Conclusion: According to the results, first trimester screening was a useful method for the prediction of SGA.

Reduced Efficacy of the Pipeline Embolization Device in the Treatment of Posterior Communicating Region Aneurysms with Fetal Posterior Cerebral Artery Configuration.

Aneurysms at the origin of the posterior communicating artery (PcommA) have been demonstrated to be effectively treated with the pipeline embolization device (PED). Much less is known about the efficacy of the PED for aneurysms associated with a fetal posterior cerebral artery (fPCA) variant. To study PED treatment efficacy of PcommA aneurysms, including fPCA aneurysms. A prospectively maintained university database of aneurysm patients treated with the PED was retrospectively reviewed. Demographics, treatment details, and imaging were reviewed for all PcommA and fPCA aneurysms. Out of a total of 285 patients treated with PED, 50 patients (mean age 57.5 ± 12.2 yr, 42 females) with unruptured PcommA (9 fPCA) aneurysms were identified. Mean follow-up duration was 14.0 ± 11.6 mo (48 patients). Roy-Raymond class I occlusion on follow-up magnetic resonance or catheter angiography (mean time 11.7 ± 6.8 mo) was achieved in 30 patients (62.5%), class II occlusion in 11 patients (22.9%) and class III occlusion in 7 patients (14.5%). The PcommA was occluded in 56% of patients without any clinical symptoms. No deaths or permanent neurological complications occurred. In fPCA aneurysms, class I occlusion was seen in 1 patient, class 2 occlusion in 2 patients, and class III occlusion in 6 patients. Multivariate analysis revealed an independent association between incomplete occlusion and fPCA configuration (OR 73.65; 95% CI: 5.84-929.13; P = .001). The PED is a safe and effective treatment for PcommA aneurysms, although fetal anatomy should increase consideration of traditional endovascular techniques or surgical clipping.

Incidental Fetal Ultrasound Findings: Interpretation and Management.

Ultrasonography is a common component of prenatal care worldwide and is often used in early pregnancy to determine gestational age, number of fetuses, fetal cardiac activity, and placental location. Patients and their families may also consider ultrasonography a social event, as it provides confirmation and reassurance of a normal pregnancy. Ultrasound screening is typically scheduled in the second trimester to visualize fetal anatomy and confirm gestational age. Most ultrasound examinations are reassuring, but some incidentally identify structural anomalies and soft markers for aneuploidy, making it necessary for health care providers to correctly interpret these findings. The health care provider's ability to prepare patients prior to the ultrasound and deliver the necessary information needed to make informed decisions regarding any follow-up screening or diagnostic testing is critical to reducing parental anxiety. Preparation for the anatomic survey should include counseling for normal and abnormal findings. The ethical concepts of patient autonomy and shared decision making are used as a guide in providing this critical information and enabling informed choices during follow-up for incidental ultrasound findings.

Fetal median sacral artery anatomy study by micro-CT imaging.

The median sacral artery (MSA) is the termination of the dorsal aorta, which undergoes a complex regression and remodeling process during embryo and fetal development. The MSA contributes to the pelvic vascularization and may be injured during pelvic surgery. The embryological steps of MSA development, anastomosis formation and anatomical variations are linked, but not fully understood. The pelvic vascularization and more precisely the MSA of a human fetus at 22 weeks of gestation (GW) were studied using micro-CT imaging. Image treatment included arterial segmentations and 3D visualization. At 22GW, the MSA was a well-developed straight artery in front of the sacrum and was longer than the abdominal aorta. Anastomoses between the MSA and the internal pudendal arteries and the superior rectal artery were detected. No evidence was found for the existence of a coccygeal glomus with arteriovenous anastomosis. Micro-CT imaging and 3D visualization helped us understand the MSA central role in pelvic vascularization through the ilio-aortic anastomotic system. It is essential to know this anastomotic network to treat pathological conditions, such as sacrococcygeal teratomas and parasitic ischiopagus twins (for instance, fetus in fetu and twin-reversed arterial perfusion sequence).

Mild fetal ventriculomegaly: diagnosis, evaluation, and management

Ventriculomegaly is defined as dilation of the fetal cerebral ventricles and is a relatively common finding on prenatal ultrasound. The purpose of this document is to review the diagnosis, evaluation, and management of mild fetal ventriculomegaly. When enlargement of the lateral ventricles (≥10 mm) is identified, a thorough evaluation should be performed, including detailed sonographic evaluation of fetal anatomy, amniocentesis for karyotype and chromosomal microarray analysis, and a workup for fetal infection. In some cases, fetal magnetic resonance imaging may identify other central nervous system abnormalities and should be considered when this technology as well as expert interpretation is available. Follow-up ultrasound examination should be performed to assess for progression of the ventricular dilation. In the setting of isolated ventriculomegaly of 10-12 mm, the likelihood of survival with normal neurodevelopment is >90%. With moderate ventriculomegaly (13-15 mm), the likelihood of normal neurodevelopment is 75-93%. The following are Society for Maternal-Fetal Medicine recommendations: We suggest that ventriculomegaly be characterized as mild (10-12 mm), moderate (13-15 mm), or severe (>15 mm) for the purposes of patient counseling, given that the chance ofan adverse outcome and potential for other abnormalities are higher when the ventricles measure 13-15 mm vs 10-12 mm (GRADE 2B); we recommend that diagnostic testing (amniocentesis) with chromosomal microarray analysis should be offered when ventriculomegaly is detected (GRADE 1B); we recommend testing for cytomegalovirus and toxoplasmosis when ventriculomegaly is detected, regardless of known exposure or symptoms (GRADE 1B); we suggest that magnetic resonance imaging be considered in cases of mild or moderate fetal ventriculomegaly when this modality and expert radiologic interpretation are available; magnetic resonance imaging is likely to be of less value if the patient has had a detailed ultrasound performed by an individual with specific experience and expertise in sonographic imaging of the fetal brain (GRADE 2B); we recommend that timing and mode of delivery be based on standard obstetric indications (GRADE 1C); we recommend that with isolated mild ventriculomegaly of 10-12 mm, after a complete evaluation, women be counseled that the outcome is favorable, and the infant is likely to be normal (GRADE 1B); we recommend that with isolated moderate ventriculomegaly of 13-15 mm, after a complete evaluation, women be counseled that the outcome is likely to be favorable but that there is an increased risk of neurodevelopmental disabilities (GRADE 1B).

Evaluation of pre- and postnatally diagnosed gastrointestinal tract obstructions

Purpose: Signs of congenital obstruction of the gastrointestinal tract (GIT) organs may present on prenatal ultrasonography. Prenatal detection is influenced by several factors, including obstruction site, lesion degree (partial or complete), the occurrence of associated malformations, and gestational week at screening. Here, we aimed to evaluate the success of prenatal diagnosis of GIT obstructions in a tertiary center in Turkey.Materials and methods: The study included 34 prenatally and 22 postnatally diagnosed babies with different GIT malformations. GIT obstructions were divided into five groups according to the level of obstruction (A. esophagus, B. stomach and proximal duodenum, C. small intestine, D. large intestine, E. multiple obstructions).Results: The prenatal detection rate among all cases was 60.7%. The associated structural malformation and aneuploidy rates were 21.4 and 5.4%, respectively. Twelve neonates died within the first day after birth due to various reasons. The remaining 43 babies underwent surgery at different times according to their clinical conditions. The mean time between birth and surgery was 4.5 days (range, 1–56 days). There were 12 postoperative deaths due to various complications, and one case died at 2 years of age. Overall, 31 of the 56 (55.4%) babies were alive during the follow-up period. The successful prenatal diagnosis rates were 57.2, 85.8, 75, 25, and 80% in groups A, B, C, D, and E, respectively. The median birth weight increased significantly in groups A through D (p = .04). However, there were no intergroup differences in the Apgar scores, associated abnormality rates, time to surgery, and number of babies operated.Conclusions: These findings demonstrate the importance of prenatal ultrasonography and success of prenatal detection especially for upper GIT abnormalities. Although there are some prenatal signs of GIT obstructions, such as double bubble, polyhydramnios, enlarged bowel, and failure to visualize the stomach, early prenatal diagnosis is difficult and can be delayed, resulting in the detection of GIT obstruction after birth. When suspecting GIT obstruction, clinicians should evaluate the fetal anatomy carefully and be aware of associated chromosomal abnormalities.

Prevention of preterm birth with pessary in singletons (PoPPS): randomized controlled trial.

To determine if pessary use prevents preterm birth (PTB) in women with singleton pregnancy, with short cervical length (CL) measured on transvaginal sonography (TVS) and without prior spontaneous PTB (sPTB). This was an open-label multicenter randomized trial of asymptomatic women presenting at 18 + 0 to 23 + 6 weeks' gestation with a singleton pregnancy, CL ≤ 25 mm on TVS and no prior sPTB. sPTB included those with spontaneous onset of labor and those with rupture of membranes prior to labor. Subjects were randomized to receive either a Bioteque cup pessary or no pessary. Pessaries were inserted by trained maternal-fetal medicine staff. Vaginal progesterone was recommended to women with CL ≤ 20 mm. The primary outcome was PTB < 37 weeks. A sample size of 121 women in each group (n = 242) was needed to detect a reduction in the primary outcome from 30% in the no-pessary group to 15% in the pessary group. The trial was stopped early before complete enrollment. Between 17 March 2014 and 29 July 2016, 17 383 women underwent CL measurement on TVS. Of these, 422 (2.4%) had CL ≤ 25 mm and 391 (92.7%) met the full eligibility criteria, of which 122 (31.2%) agreed to randomization. Sixty-one (50%) women were randomized to the pessary group and 61 (50%) to the no-pessary group. Baseline characteristics were similar between the groups. There were no significant differences between the pessary and no-pessary groups in the rate of PTB < 37 weeks (43% vs 40%; relative risk 1.09; 95% CI, 0.71-1.68) or in secondary outcomes, such as rate of PTB < 34 weeks, rate of PTB < 28 weeks, gestational age at delivery, birth weight and rate of composite adverse neonatal outcome. Cervical pessary use was not associated with prevention of PTB in women with a singleton pregnancy, short CL on TVS and no prior sPTB in this small, underpowered randomized controlled trial. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.