The Arabin pessary to prevent preterm birth in women with a twin pregnancy and a short cervix: the STOPPIT 2 RCT.

BACKGROUND: Preterm birth is common in twins and accounts for significant mortality and morbidity. There are no effective preventative treatments. Some studies have suggested that, in twin pregnancy complicated by a short cervix, the Arabin pessary, which fits around the cervix and can be inserted as an outpatient procedure, reduces preterm birth and prevents neonatal morbidity. OBJECTIVE: STOPPIT 2 aimed to evaluate the clinical utility of the Arabin cervical pessary in preventing preterm birth in women with a twin pregnancy and a short cervix. DESIGN: STOPPIT 2 was a pragmatic, open label, multicentre randomised controlled trial with two treatment group - the Arabin pessary plus standard care (intervention) and standard care alone (control). Participants were initially recruited into the screening phase of the study, when cervical length was measured. Women with a measured cervical length of ≤ 35 mm were then recruited into the treatment phase of the study. An economic evaluation considered cost-effectiveness and a qualitative substudy explored the experiences of participants and clinicians. SETTING: Antenatal clinics in the UK and elsewhere in Europe. PARTICIPANTS: Women with twin pregnancy at < 21 weeks' gestation with known chorionicity and gestation established by scan at ≤ 16 weeks' gestation. INTERVENTIONS: Ultrasound scan to establish cervical length. Women with a cervical length of ≤ 35 mm at 18+ 0-20+ 6 weeks' gestation were randomised to standard care or Arabin pessary plus standard care. Randomisation was performed by computer and accessed through a web-based browser. MAIN OUTCOME MEASURES: Obstetric - all births before 34+ 0 weeks' gestation following the spontaneous onset of labour; and neonatal - composite of adverse outcomes, including stillbirth or neonatal death, periventricular leukomalacia, early respiratory morbidity, intraventricular haemorrhage, necrotising enterocolitis or proven sepsis, all measured up to 28 days after the expected date of delivery. RESULTS: A total of 2228 participants were recruited to the screening phase, of whom 2170 received a scan and 503 were randomised: 250 to Arabin pessary and 253 to standard care alone. The rate of the primary obstetric outcome was 18.4% (46/250) in the intervention group and 20.6% (52/253) in the control group (adjusted odds ratio 0.87, 95% confidence interval 0.55 to 1.38; p = 0.54). The rate of the primary neonatal outcome was 13.4% (67/500) and 15.0% (76/506) in the intervention group and control group, respectively (adjusted odds ratio 0.86, 95% confidence interval 0.54 to 1.36; p = 0.52). The pessary was largely well tolerated and clinicians found insertion and removal 'easy' or 'fairly easy' in the majority of instances. The simple costs analysis showed that pessary treatment is no more costly than standard care. LIMITATIONS: There was the possibility of a type II error around smaller than anticipated benefit. CONCLUSIONS: In this study, the Arabin pessary did not reduce preterm birth or adverse neonatal outcomes in women with a twin pregnancy and a short cervix. The pessary either is ineffective at reducing preterm birth or has an effect size of < 0.4. FUTURE WORK: Women with twin pregnancy remain at risk of preterm birth; work is required to find treatments for this. TRIAL REGISTRATION: Current Controlled Trials ISRCTN98835694 and ClinicalTrials.gov NCT02235181. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 44. See the NIHR Journals Library website for further project information.

Women who are pregnant with twins have a much higher risk of going into labour early and having an early (preterm) birth than women who are pregnant with only one baby. For this reason, babies who are twins are much more likely to die or to have serious health complications in the first months of life. Although we know that women with twin pregnancy are at risk, there are no treatments that are recommended to prevent early births. Some studies have suggested that the Arabin pessary can help. The Arabin pessary is a silicone ring that fits around the cervix (neck of the womb). The pessary can be put in place in a clinic without any need for an anaesthetic. Some studies have suggested that the Arabin pessary helps and others have suggested that it does not. It appears to be most helpful when the cervix (neck of the womb) is already shortening. Shortening of the neck of the womb is a sign that early birth is even more likely. We asked women with twin pregnancy to take part in STOPPIT 2. Women who agreed had an ultrasound scan of the neck of the womb, which measured its length. Those with a short cervix were randomised to be offered the Arabin pessary (in addition to standard care) or standard care alone. This allocation was carried out 'at random' by a computer. We followed women up until the end of their pregnancy and collected information on the babies' health after birth. We found that the Arabin pessary did not reduce the risk of an early birth; nor did it reduce the risk of health complications for the baby. We conclude that the Arabin pessary should not be used for this purpose.

Exome Sequencing for Prenatal Detection of Genetic Abnormalities in Fetal Ultrasound Anomalies: An Economic Evaluation.

INTRODUCTION: In light of the prospective Prenatal Assessment of Genomes and Exomes (PAGE) study, this paper aimed to determine the additional costs of using exome sequencing (ES) alongside or in place of chromosomal microarray (CMA) in a fetus with an identified congenital anomaly. METHODS: A decision tree was populated using data from a prospective cohort of women undergoing invasive diagnostic testing. Four testing strategies were evaluated: CMA, ES, CMA followed by ES ("stepwise"); CMA and ES combined. RESULTS: When ES is priced at GBP 2,100 (EUR 2,407/USD 2,694), performing ES alone prenatally would cost a further GBP 31,410 (EUR 36,001/USD 40,289) per additional genetic diagnosis, whereas the stepwise would cost a further GBP 24,657 (EUR 28,261/USD 31,627) per additional genetic diagnosis. When ES is priced at GBP 966 (EUR 1,107/USD 1,239), performing ES alone prenatally would cost a further GBP 11,532 (EUR 13,217/USD 14,792) per additional genetic diagnosis, whereas the stepwise would cost a further additional GBP 11,639 (EUR 13,340/USD 14,929) per additional genetic diagnosis. The sub-group analysis suggests that performing stepwise on cases indicative of multiple anomalies at ultrasound scan (USS) compared to cases indicative of a single anomaly, is more cost-effective compared to using ES alone. DISCUSSION/CONCLUSION: Performing ES alongside CMA is more cost-effective than ES alone, which can potentially lead to improvements in pregnancy management. The direct effects of test results on pregnancy outcomes were not examined; therefore, further research is recommended to examine changes on the projected incremental cost-effectiveness ratios.

MRI in the diagnosis of fetal developmental brain abnormalities: the MERIDIAN diagnostic accuracy study.

BACKGROUND: Ultrasonography has been the mainstay of antenatal screening programmes in the UK for many years. Technical factors and physical limitations may result in suboptimal images that can lead to incorrect diagnoses and inaccurate counselling and prognostic information being given to parents. Previous studies suggest that the addition of in utero magnetic resonance imaging (iuMRI) may improve diagnostic accuracy for fetal brain abnormalities. These studies have limitations, including a lack of an outcome reference diagnosis (ORD), which means that improvements could not be assessed accurately. OBJECTIVES: To assess the diagnostic impact, acceptability and cost consequence of iuMRI among fetuses with a suspected fetal brain abnormality. DESIGN: A pragmatic, prospective, multicentre, cohort study with a health economics analysis and a sociological substudy. SETTING: Sixteen UK fetal medicine centres. PARTICIPANTS: Pregnant women aged ≥ 16 years carrying a fetus (at least 18 weeks' gestation) with a suspected brain abnormality detected on ultrasonography. INTERVENTIONS: Participants underwent iuMRI and the findings were reported to their referring fetal medicine clinician. MAIN OUTCOME MEASURES: Pregnancy outcome was followed up and an ORD from postnatal imaging or postmortem autopsy/imaging collected when available. Developmental data from the Bayley Scales of Infant Development and questionnaires were collected from the surviving infants aged 2-3 years. Data on the management of the pregnancy before and after the iuMRI were collected to inform the economic evaluation. Two surveys collected data on patient acceptability of iuMRI and qualitative interviews with participants and health professionals were undertaken. RESULTS: The primary analysis consisted of 570 fetuses. The absolute diagnostic accuracies of ultrasonography and iuMRI were 68% and 93%, respectively [a difference of 25%, 95% confidence interval (CI) 21% to 29%]. The difference between ultrasonography and iuMRI increased with gestational age. In the 18-23 weeks group, the figures were 70% for ultrasonography and 92% for iuMRI (difference of 23%, 95% CI 18% to 27%); in the ≥ 24 weeks group, the figures were 65% for ultrasonography and 94% for iuMRI (difference of 29%, 95% CI 23% to 36%). Patient acceptability was high, with at least 95% of respondents stating that they would have iuMRI again in a similar situation. Health professional interviews suggested that iuMRI was acceptable to clinicians and that iuMRI was useful as an adjunct to ultrasonography, but not as a replacement. Across a range of scenarios, iuMRI resulted in additional costs compared with ultrasonography alone. The additional cost was consistently < £600 per patient and the cost per management decision appropriately changed was always < £3000. There is potential for reporting bias from the referring clinicians on the diagnostic and prognostic outcomes. Lower than anticipated follow-up rates at 3 years of age were observed. CONCLUSIONS: iuMRI as an adjunct to ultrasonography significantly improves the diagnostic accuracy and confidence for the detection of fetal brain abnormalities. An evaluation of the use of iuMRI for cases of isolated microcephaly and the diagnosis of fetal spine abnormalities is recommended. Longer-term follow-up studies of children diagnosed with fetal brain abnormalities are required to fully assess the functional significance of the diagnoses. TRIAL REGISTRATION: Current Controlled Trials ISRCTN27626961. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 49. See the NIHR Journals Library website for further project information.

Ultrasonography is routine in pregnancy to check that the baby's brain is developing as expected. However, no medical test is perfect and ultrasonography may miss some brain abnormalities, may get some brain abnormalities wrong or may diagnose an abnormality that is not really present. Magnetic resonance imaging (MRI) may help clarify difficult cases during pregnancy. We wanted to find out if MRI was better than ultrasonography alone in making an accurate diagnosis. We recruited pregnant women whose ultrasound scan, performed by an expert, suggested that their baby had a brain abnormality, and referred them for a MRI scan. The results of the two tests were compared with each other and to the final outcome of the pregnancy. Our results showed that using MRI in addition to ultrasonography improved the accuracy of the diagnosis in about one in four pregnancies. It changed the prediction of how the baby would develop in at least one in five cases. In many cases, the pregnancy was managed differently because of the MRI result. The MRI was acceptable to women, with 95% saying that they would have MRI again in a similar situation. Neither MRI nor ultrasonography accurately identified children who went on to have delayed development at the age of 2­3 years, but MRI was better than ultrasonography at ruling out developmental problems at this age. The MRI cost more than ultrasonography alone; therefore, whether or not it is worthwhile depends on the value placed on the decisions that changed as a result of its use.

Exome sequencing in the assessment of congenital malformations in the fetus and neonate.

Major congenital anomalies are often associated with perinatal mortality, long-term morbidity and prolonged hospitalisation. Prenatal ultrasound remains the principle diagnostic test for many anomalies, but despite this up to one-third are only identified in the neonatal period. The primary step in determining underlying aetiology is to define accurately the phenotype by recognition of dysmorphology (both prenatally and postnatally). The potential introduction of next-generation sequencing, primarily through exome sequencing, into perinatal practice may improve the pathological diagnostic yield. However, clinicians must understand both the benefit and potential harms of this technology in facilitating the discovery of relevant pathogenic variants in the diagnosis and management of congenital malformations.

Open randomised trial of the (Arabin) pessary to prevent preterm birth in twin pregnancy with health economics and acceptability: STOPPIT-2-a study protocol.

INTRODUCTION: The STOPPIT-2 study aims to determine the clinical utility of the Arabin cervical pessary in preventing preterm birth in women with a twin pregnancy and a short cervix, about which there is current uncertainty. STOPPIT-2 will resolve uncertainty around effectiveness for women with a twin pregnancy and a cervical length of 35 mm or less, define adverse effects, ascertain acceptability and estimate National Health Service costs and savings. METHODS: STOPPIT-2 is a pragmatic multicentre open-label randomised controlled trial. Consenting women with twin pregnancy will have an transvaginal ultrasound scan of their cervical length performed between 18+0 and 20+6 weeks' gestation by an accredited practitioner: women with a cervical length of ≤35 mm will be eligible for inclusion in the treatment phase of the study. The intervention by the insertion of the Arabin cervical pessary will be compared with standard treatment (no pessary).The primary outcomes are (obstetric) spontaneous onset of labour for the mother leading to delivery before 34 weeks' gestation and (neonatal) a composite of specific adverse outcomes or death occurring up to the end of the first 4 weeks after the estimated date of delivery to either or both babies.We plan to recruit 500 women in the treatment phase of the study. Assuming a treatment effect of 0.6, and background rates of 35% and 18%, respectively, for each of the primary outcomes, our study has 85% power to detect a difference between the intervention and the control groups. ANALYSIS: Data will be analysed on the intention-to-treat principle. ETHICS: STOPPIT-2 was approved by the South East Scotland Ethics Committee 02 on 29 August 2014, reference number 14/SS/1031 IRAS ID 159610. DISSEMINATION: Peer reviewed journals, presentations at national and international scientific meetings. TRIAL REGISTRATION NUMBER: ISRCTN98835694 and NCT02235181.

Clinical utility of exome sequencing in the prenatal diagnosis of congenital anomalies: A Review.

Advances in prenatal genomics have enabled the assessment of not only the sub-microscopic structure of chromosomes using chromosomal microarray analysis, but also the detection of "pathogenic variants" to the resolution of a single base pair with the use of next generation sequencing. Research is emerging on the additional prenatal diagnostic yield that exome sequencing offers when structural fetal anomalies are detected on ultrasound examination, in particular the identification of monogenic abnormalities defining prognosis and recurrence of anomalies. Primarily assessed using fetal DNA obtained by invasive techniques (amniocytes or chorionic villi), this technology is progressing into a non-invasive approach using maternal plasma. There are several challenges, to be addressed before this technology can be introduced into routine clinical practice. These are primarily technical and interpretational but also relate to service provision; cost-effectiveness; turn-around time; patient acceptability and ethical dilemmas. With adequate pre- and post-test counselling many of these challenges may be overcome and such counselling has to be multi-disciplinary, involving clinical geneticists, genetic scientists, paediatricians, perinatal pathologists and fetal medicine subspecialists. There is therefore a need for obstetricians to have an understanding of the clinical utility, application, advantages and challenges of such technologies before introduction into routine clinical practice.

Use of MRI in the diagnosis of fetal brain abnormalities in utero (MERIDIAN): a multicentre, prospective cohort study.

BACKGROUND: In-utero MRI (iuMRI) has shown promise as an adjunct to ultrasound but the comparative diagnostic performance has been poorly defined. We aimed to assess whether the diagnostic accuracy and confidence of the prenatal diagnosis of fetal brain abnormalities is improved with iuMRI and assess the clinical impact and patient acceptability of iuMRI. METHODS: We did a multicentre, prospective, cohort study in the UK, at 16 fetal medicine centres, of pregnant women aged 16 years or older whose fetus had a brain abnormality detected by ultrasound at a gestational age of 18 weeks or more, had no contraindications to iuMRI, and consented to enter the study. Women carrying a fetus suspected of having a brain anomaly on ultrasound had iuMRI done within 14 days of ultrasound. The findings were reviewed by two independent panels and used to estimate diagnostic accuracy and confidence by comparison with outcome diagnoses. Changes in diagnosis, prognosis, and clinical management brought about by iuMRI and patient acceptability were assessed. FINDINGS: Participants were recruited between July 29, 2011, and Aug 31, 2014. The cohort was subdivided by gestation into the 18 weeks to less than 24 weeks fetus cohort (n=369) and into the 24 weeks or older fetus cohort (n=201). Diagnostic accuracy was improved by 23% (95% CI 18-27) in the 18 weeks to less than 24 weeks group and 29% (23-36) in the 24 weeks and older group (p<0·0001 for both groups). The overall diagnostic accuracy was 68% for ultrasound and 93% for iuMRI (difference 25%, 95% CI 21-29). Dominant diagnoses were reported with high confidence on ultrasound in 465 (82%) of 570 cases compared with 544 (95%) of 570 cases on iuMRI. IuMRI provided additional diagnostic information in 387 (49%) of 783 cases, changed prognostic information in at least 157 (20%), and led to changes in clinical management in more than one in three cases. IuMRI also had high patient acceptability with at least 95% of women saying they would have an iuMRI study if a future pregnancy were complicated by a fetal brain abnormality. INTERPRETATION: iuMRI improves diagnostic accuracy and confidence for fetal brain anomalies and leads to management changes in a high proportion of cases. This finding, along with the high patient acceptability, leads us to propose that any fetus with a suspected brain abnormality on ultrasound should have iuMRI to better inform counselling and management decisions. FUNDING: National Institute for Health Research Health Technology Assessment programme.

BAC chromosomal microarray for prenatal detection of chromosome anomalies in fetal ultrasound anomalies: an economic evaluation.

INTRODUCTION: To determine the cost-effectiveness of prenatal chromosomal microarray (CMA) when performed for structural anomalies on fetal ultrasound scan over conventional techniques. METHOD: A decision tree was populated using data from a prospective cohort of women undergoing testing when a fetal ultrasound scan showed a structural abnormality. Nine strategies of testing were modeled including combinations of the tests: QFPCR, G-band karyotyping, CMA and FISH for DiGeorge (22q) microdeletion. RESULTS: When CMA costs GBP 405 and using a 1-Mb BAC array it would cost GBP 24,600 for every additional case detected by CMA over a combination of QFPCR, followed by G-band karyotype, followed lastly by FISH (for DiGeorge syndrome). If CMA is performed instead of conventional karyotyping alone it costs GBP 33,000 for every additional case detected. However, if the cost of CMA is reduced to GBP 360 than when CMA is performed instead of conventional karyotyping alone it would cost GBP 9,768 for every additional case detected. DISCUSSION: The use of a prenatal BAC CMA is not currently cost-effective when compared to other testing strategies. However, as CMA costs decrease and resolution (and detection rates) increase it is likely to become the cost-effective option of the future.

Evaluation of the cost effectiveness of vesico-amniotic shunting in the management of congenital lower urinary tract obstruction (based on data from the PLUTO Trial).

OBJECTIVE: To determine the cost-effectiveness of in-utero percutaneous Vesico Amniotic Shunt (VAS) in the management of fetal lower urinary tract obstruction (LUTO). DESIGN: Model based economic analysis using data from the randomised controlled arm of the PLUTO (percutaneous vesico-amniotic shunting for lower urinary tract obstruction) trial. SETTING: Fetal medicine departments in United Kingdom, Ireland and Netherlands. POPULATION OR SAMPLE: Pregnant women with a male, singleton fetus with LUTO. METHODS: Costs and outcomes were prospectively collected in the trial; three separate base case analyses were performed using the intention to treat (ITT), per protocol and uniform prior methods. Deterministic and probabilistic sensitivity analyses were performed to explore data uncertainty. MAIN OUTCOME MEASURES: Survival at 28 days, 1 year and disease free survival at 1 year. RESULTS: VAS was more expensive but appeared to result in higher rates of survival compared with conservative management in patients with LUTO. Using ITT analysis the incremental cost effectiveness ratios based on outcomes of survival at 28 days, 1 year, or 1 morbidity-free year on the VAS arm were £ 15,506, £ 15,545, and £ 43,932, respectively. CONCLUSIONS: VAS is a more expensive option compared to the conservative approach in the management of individuals with LUTO. Data from the RCT suggest that VAS improves neonatal survival but does not result in significant improvements in morbidity. Our analysis concludes that VAS is not likely to be cost effective in the management of these patients given the NICE (National Institute of Health and Clinical Excellence) cost threshold of £ 20,000 per QALY.