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Allen VM, Dodge A, Fahey J, Teixeira E, Woolcott CG. Fetal, neonatal, and infant mortality surveillance in Nova Scotia: a population-based cohort study examining temporal trends from 1988 to 2022. JOURNAL OF OBSTETRICS AND GYNAECOLOGY CANADA 2025:102929. [PMID: 40398839 DOI: 10.1016/j.jogc.2025.102929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2025] [Revised: 04/01/2025] [Accepted: 04/07/2025] [Indexed: 05/23/2025]
Abstract
OBJECTIVE To describe annual trends in the incidence of stillbirth and infant mortality XXXXX over a 35-year period. METHODS A population-based cohort study of deliveries between 1988 and 2022 was conducted using data from the provincial, clinically-oriented XXXXX database. All pregnancies ≥20 weeks' gestation or ≥500 g were included. Rates of fetal death (per 1000 births), and neonatal and infant mortality (per 1000 live births) were calculated by birth year. Rates were reported for the entire cohort and stratified by birth parent age, birthweight for gestational age and sex, and number of fetuses. RESULTS A total of 334 776 deliveries were included, with 332 975 of these being live births; there were 1801 stillbirths, 1082 neonatal deaths, and 1579 infant deaths. Rates of fetal, neonatal, and infant death decreased between 1988-1992 and 2018-2022 (6.8 to 4.8, 4.0 to 2.5, and 6.3 to 4.0, per 1000 births, respectively). Rates increased somewhat in later 5-year epochs among those ≥35 years of age. Rates in the <10th percentile of birthweight for gestational age were highest in earlier epochs and showed a general downward trend with each epoch except the last. Marked temporal reductions in rates among multiple gestations were observed. CONCLUSION Increases in mortality in later epochs, and among select birth parent and infant factors, suggest that patient characteristics and clinical practice changes may play a role in these increases. The observed temporal changes are important in informing evaluation of factors associated with stillbirth and infant mortality.
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Affiliation(s)
- Victoria M Allen
- Department of Obstetrics & Gynaecology, Dalhousie University and IWK Health.
| | - Amy Dodge
- Department of Obstetrics & Gynaecology, Dalhousie University and IWK Health
| | - John Fahey
- Reproductive Care Program of Nova Scotia, IWK Health
| | | | - Christy G Woolcott
- Department of Obstetrics & Gynaecology, Dalhousie University and IWK Health; Department of Pediatrics, Dalhousie University and IWK Health
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O'Connor C, Leitao S, Corcoran P, O'Donoghue K. Perinatal deaths in twin and singleton infants in Ireland: A comparison of characteristics and causes. Ir J Med Sci 2025; 194:167-180. [PMID: 39495474 DOI: 10.1007/s11845-024-03829-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Accepted: 10/18/2024] [Indexed: 11/05/2024]
Abstract
INTRODUCTION Twin pregnancies are associated with significantly higher perinatal mortality (PM) rates compared to singletons, primarily due to complications like fetal growth restriction, preterm birth, and congenital anomalies. This study aimed to compare the characteristics associated with PM in twin pregnancies and compare maternal and obstetric factors and cause of death among twins and singletons in the Republic of Ireland. MATERIALS AND METHODS Data spanning 2011 to 2022 from the National Perinatal Epidemiology Centre's annual perinatal mortality clinical audit included 4494 perinatal deaths. Maternal characteristics, antenatal care factors and cause of death were analysed with relative risk calculated using national Hospital In-Patient Enquiry data. Pearson's chi-squared tests studied the difference between mortality in twins and singletons. RESULTS Twins accounted for 10.4% of all perinatal deaths, despite representing only 3.6% of total births. The PM rate for twins was 17.3 per 1000 births, 3.1 times higher than for singletons. Early neonatal deaths (ENNDs) were more frequent in twins (54.2%), while stillbirths predominated among singletons (68.6%). Younger maternal age and lower BMI were associated with higher PM risks in twins. A considerable proportion of twin deaths with major congenital anomalies or birth before 28 weeks gestation occurred in non-tertiary hospitals, suggesting limitations in referral pathways to centres with appropriate neonatal expertise. CONCLUSION Twin pregnancies pose a higher risk of perinatal mortality, particularly among younger mothers and preterm births. The findings highlight the need for updated guidelines that prioritise early risk assessment, targeted interventions, and improved referral systems.
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Affiliation(s)
- Caroline O'Connor
- INFANT Research Centre, University College Cork, Cork, Ireland.
- Pregnancy Loss Research Group, Department of Obstetrics & Gynecology, University College Cork, Cork, Ireland.
| | - Sara Leitao
- Pregnancy Loss Research Group, Department of Obstetrics & Gynecology, University College Cork, Cork, Ireland
- National Perinatal Epidemiology Center (NPEC), University College Cork, Cork, Ireland
| | - Paul Corcoran
- National Perinatal Epidemiology Center (NPEC), University College Cork, Cork, Ireland
| | - Keelin O'Donoghue
- INFANT Research Centre, University College Cork, Cork, Ireland
- Pregnancy Loss Research Group, Department of Obstetrics & Gynecology, University College Cork, Cork, Ireland
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Kuitunen I. Neonatal outcomes in twin pregnancies in Finland from 2008 to 2023. Eur J Pediatr 2025; 184:158. [PMID: 39875784 PMCID: PMC11775026 DOI: 10.1007/s00431-025-05996-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2024] [Revised: 01/15/2025] [Accepted: 01/18/2025] [Indexed: 01/30/2025]
Abstract
Twin pregnancies are associated with higher risks of adverse maternal and neonatal outcomes compared to singleton pregnancies. This retrospective nationwide cohort study analyzed trends in twin pregnancy outcomes in Finland from 2008 to 2023 using data from the Finnish Medical Birth Register. Outcomes assessed included perinatal mortality, stillbirths, neonatal mortality, neonatal intensive care unit (NICU) admissions, and hospitalization rates at one week of age. A total of 23,588 twin births were included, with an overall stillbirth rate of 9.0 per 1000 and a perinatal mortality rate of 16.0 per 1000. Neonatal mortality rates declined significantly, with term twins showing a rate of 0.9 per 1000 and preterm twins 4.6 per 1000 in the latest years of 2022-2023. NICU admission rates remained stable for preterm twins but showed an increasing trend for term twins. The rate of hospitalized neonates at the age of seven days decreased over time. CONCLUSION These trends align with improved antenatal care and Finland's reputation for low neonatal mortality. However, increasing maternal age and obesity rates may contribute to rising NICU admissions in term twins. The study highlights the need for continuous monitoring of neonatal outcomes to ensure high standards of care in the context of declining fertility and delivery rates in Finland. WHAT IS KNOWN • Twin pregnancies are associated with higher risks of adverse maternal and neonatal outcomes compared to singleton pregnancies. • Finland has one of the lowest neonatal mortality rates globally. WHAT IS NEW • Neonatal mortality rates declined significantly both in term and preterm twins from 2008 to 2023. • NICU admission rates remained stable for preterm twins but showed an increasing trend for term twins.
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Affiliation(s)
- Ilari Kuitunen
- Institute of Clinical Medicine and Department of Pediatrics, University of Eastern Finland, Kuopio, Finland.
- Department of Pediatrics, Kuopio University Hospital, Puijonlaaksontie 2, 70210, Kuopio, Finland.
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Marleen S, Kodithuwakku W, Nandasena R, Mohideen S, Allotey J, Fernández-García S, Gaetano-Gil A, Ruiz-Calvo G, Aquilina J, Khalil A, Bhide P, Zamora J, Thangaratinam S. Maternal and perinatal outcomes in twin pregnancies following assisted reproduction: a systematic review and meta-analysis involving 802 462 pregnancies. Hum Reprod Update 2024; 30:309-322. [PMID: 38345641 PMCID: PMC11063550 DOI: 10.1093/humupd/dmae002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/16/2023] [Indexed: 05/03/2024] Open
Abstract
BACKGROUND ART is associated with higher rates of twin pregnancies than singleton pregnancies. Whether twin pregnancies conceived following ART have additional maternal and neonatal complications compared with non-ART twin pregnancies is not known. OBJECTIVE AND RATIONALE The objective was to quantify the risk of adverse maternal and perinatal outcomes among twin pregnancies conceived following ART compared with non-ART and natural conception. Existing reviews vary in the reported outcomes, with many studies including triplet pregnancies in the study population. Therefore, we aimed to perform an up-to-date review with an in-depth analysis of maternal and perinatal outcomes limited to twin pregnancies. SEARCH METHODS We searched electronic databases MEDLINE and EMBASE from January 1990 to May 2023 without language restrictions. All cohort studies reporting maternal and perinatal outcomes following ART compared with non-ART twin pregnancies and natural conception were included. Case-control studies, case reports, case series, animal studies, and in vitro studies were excluded. The Newcastle-Ottawa Scale was used to assess the methodological quality of the studies. Using random-effects meta-analysis, the estimates were pooled and the findings were reported as odds ratios (OR) with 95% CI. OUTCOMES We included 111 studies (802 462 pregnancies). Twin pregnancies conceived following ART were at higher risk of preterm birth at <34 weeks (OR 1.33, 95% CI 1.14-1.56, 29 studies, I2 = 73%), <37 weeks (OR 1.26, 95% CI 1.19-1.33, 70 studies, I2 = 76%), hypertensive disorders in pregnancy (OR 1.29, 95% CI 1.14-1.46, 59 studies, I2 = 87%), gestational diabetes mellitus (OR 1.61, 95% CI 1.48-1.75, 51 studies, I2 = 65%), and caesarean delivery (OR 1.80, 95% CI 1.65-1.97, 70 studies, I2 = 89%) compared with non-ART twins. The risks for the above maternal outcomes were also increased in the ART group compared with natural conception. Of the perinatal outcomes, ART twins were at significantly increased risk of congenital malformations (OR 1.17, 95% CI 1.05-1.30, 39 studies, I2 = 59%), birthweight discordance (>25% (OR 1.31, 95% CI 1.05-1.63, 7 studies, I2 = 0%)), respiratory distress syndrome (OR 1.32, 95% CI 1.09-1.60, 16 studies, I2 = 61%), and neonatal intensive care unit admission (OR 1.24, 95% CI 1.14-1.35, 32 studies, I2 = 87%) compared with non-ART twins. When comparing ART with natural conception, the risk of respiratory distress syndrome, intensive care admissions, and birthweight discordance >25% was higher among the ART group. Perinatal complications, such as stillbirth (OR 0.83, 95% CI 0.70-0.99, 33 studies, I2 = 49%), small for gestational age <10th centile (OR 0.90, 95% CI 0.85-0.95, 26 studies, I2 = 36%), and twin-twin transfusion syndrome (OR 0.45, 95% CI 0.25-0.82, 9 studies, I2 = 25%), were reduced in twin pregnancies conceived with ART versus those without ART. The above perinatal complications were also fewer amongst the ART group than natural conception. WIDER IMPLICATIONS ART twin pregnancies are associated with higher maternal complications than non-ART pregnancies and natural conception, with varied perinatal outcomes. Women seeking ART should be counselled about the increased risks of ART twin pregnancies and should be closely monitored in pregnancy for complications. We recommend exercising caution when interpreting the study findings owing to the study's limitations.
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Affiliation(s)
- Shemoon Marleen
- Barts Research Centre for Women’s Health (BARC), Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
- Department of Obstetrics and Gynaecology, Sri Jayewardenepura Postgraduate Teaching Hospital, Nugegoda, Sri Lanka
| | - Wasana Kodithuwakku
- Institute of Neurology, National Hospital of Sri Lanka, Colombo 10, Sri Lanka
| | - Ruvini Nandasena
- Department of Obstetrics and Gynaecology, Sri Jayewardenepura Postgraduate Teaching Hospital, Nugegoda, Sri Lanka
| | - Shezoon Mohideen
- Department of Obstetrics and Gynaecology, Sri Jayewardenepura Postgraduate Teaching Hospital, Nugegoda, Sri Lanka
| | - John Allotey
- World Health Organization (WHO) Collaborating Centre for Global Women’s Health, Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK
| | - Silvia Fernández-García
- World Health Organization (WHO) Collaborating Centre for Global Women’s Health, Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK
| | - Andrea Gaetano-Gil
- Clinical Biostatistics Unit, Hospital Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (CIBERESP), Madrid, Spain
| | - Gabriel Ruiz-Calvo
- Clinical Biostatistics Unit, Hospital Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (CIBERESP), Madrid, Spain
| | | | - Asma Khalil
- St George’s University Hospitals NHS Foundation Trust, London, UK
- Molecular and Clinical Sciences Research Institute, St George’s Medical School, University of London, London, UK
| | - Priya Bhide
- Barts Research Centre for Women’s Health (BARC), Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Javier Zamora
- World Health Organization (WHO) Collaborating Centre for Global Women’s Health, Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK
- Clinical Biostatistics Unit, Hospital Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (CIBERESP), Madrid, Spain
| | - Shakila Thangaratinam
- World Health Organization (WHO) Collaborating Centre for Global Women’s Health, Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK
- Birmingham Women’s and Children’s NHS Foundation Trust, Birmingham, UK
- NIHR Biomedical Research Centre, Birmingham, UK
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Vlachadis N, Stavros S, Machairiotis N, Vrachnis D, Loukas N, Antonakopoulos N, Fotiou A, Maroudias G, Drakakis P, Vrachnis N. The Contribution of Multiple Pregnancies in Stillbirths in Greece: A Time-Trend Analysis. Cureus 2024; 16:e54628. [PMID: 38523936 PMCID: PMC10959416 DOI: 10.7759/cureus.54628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/21/2024] [Indexed: 03/26/2024] Open
Abstract
Introduction Multiple pregnancy is an established risk factor for fetal death. This study aimed to examine the impact of multifetal pregnancies on stillbirth rates (SBRs) in the Greek population. Methods Data on live births and stillbirths by multiplicity were derived from the Hellenic Statistical Authority, covering a 65-year period from 1957 to 2021. The SBR for multiple and single gestations, and the population attributable risk (%) (PAR (%)) stillbirth attributable to multifetal gestations were calculated, and temporal trends were assessed using joinpoint regression analysis, with annual percentage changes (APC) and 95% confidence interval (95% CI). Results In the period 1957-2021, multiple pregnancies accounted for 9.4% of total stillbirths in Greece and the overall relative risk of fetal death among multifetal gestations was 3.34, in comparison with singletons. The SBR in multiple births remained unchanged from 1957 to 1976 and showed downward trends from 1976 to 2021 (APC = -3.0, 95% CI: -3.4 to -2.7, p < 0.001). PAR (%), after two decades of stability, showed an increasing trend over the period 1975-2011 (APC = 3.4, 95% CI: 2.8 to 4.0, p < 0.001), which was reversed in the more recent decade 2011-2021 (APC = -6.1, 95% CI: -9.6 to -2.5, p = 0.001), with PAR (%) decreasing from a historical high of 19.3% in 2012 to 8.6% in 2021. Conclusion The high incidence of multiple births has a considerable impact on stillbirth rates in the Greek population. The recent downward trends of SBR and PAR (%) of multiple gestations are encouraging, however more measures and targeted interventions are needed to improve perinatal outcomes in multifetal gestation.
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Affiliation(s)
- Nikolaos Vlachadis
- Department of Obstetrics and Gynecology, General Hospital of Messinia, Kalamata, GRC
| | - Sofoklis Stavros
- Third Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens, Attiko Hospital, Athens, GRC
| | - Nikolaos Machairiotis
- Third Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens, Attiko Hospital, Athens, GRC
| | - Dionysios Vrachnis
- Third Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens, Attiko Hospital, Athens, GRC
| | - Nikolaos Loukas
- Third Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens, Attiko Hospital, Athens, GRC
| | | | - Alexandros Fotiou
- Third Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens, Attiko Hospital, Athens, GRC
| | - Georgios Maroudias
- Third Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens, Attiko Hospital, Athens, GRC
| | - Petros Drakakis
- Third Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens, Attiko Hospital, Athens, GRC
| | - Nikolaos Vrachnis
- Third Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens, Attiko Hospital, Athens, GRC
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Whittaker M, Greatholder I, Kilby MD, Heazell AEP. Risk factors for adverse outcomes in twin pregnancies: a narrative review. J Matern Fetal Neonatal Med 2023; 36:2240467. [PMID: 37518183 DOI: 10.1080/14767058.2023.2240467] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/14/2023] [Accepted: 07/19/2023] [Indexed: 08/01/2023]
Abstract
PURPOSE Globally, the incidence of twin pregnancies is rising owing to the use of assisted reproductive technologies (ART), emigration and deferment of pregnancy until advanced maternal age (AMA). While twin pregnancies have higher absolute risks of adverse outcomes, including miscarriage, stillbirth, neonatal death and preterm delivery, the impact of specific exposures and risk factors related to these outcomes may differ between twin pregnancies and singleton pregnancies. Regarding modifiable factors, data are sometimes based on evidence extrapolated from singleton or whole obstetric populations. Therefore, targeted evidence is required to provide care tailored to twin pregnancies to prevent adverse outcomes. We aimed to comprehensively review the association between different risk factors and adverse outcomes in twin pregnancies, including data on chorionicity, and to compare these to singletons. MATERIALS AND METHODS This review examines the risks associated with chorionicity, AMA, body mass index (BMI), socioeconomic and ethnic inequalities, maternal smoking, use of ART, maternal perception of fetal movement, and maternal comorbidities, including hypertensive disorders of pregnancy (HDP) and gestational diabetes mellitus (GDM). Adverse outcomes reported were preterm birth, admission to the neonatal intensive care unit (NICU), stillbirth and neonatal mortality. As such, fetal mortality and morbidity will be under-represented, as pregnancy loss before 22-24 weeks is omitted. RESULTS Monochorionicity increases the risk of stillbirth, NICU admission, and preterm delivery in twin pregnancy. AMA predisposes twin pregnancies to higher risks of mortality, admission to the NICU, and preterm birth than singleton pregnancies do. Conversely, the impact of BMI, socioeconomic inequalities, smoking, ART, and HDP on adverse outcomes appears to be lower in twin pregnancies than in singleton pregnancies. This attenuation might be explained by the higher baseline risk of adverse outcomes such as preterm birth in twin pregnancies. Some exposures, such as ART use and GDM, appear to be "protective" against perinatal mortality in twin pregnancies, despite being established risk factors for adverse outcomes in singleton pregnancies, potentially related to access to specialist care. There is a paucity of evidence available to counsel mothers of twin pregnancies regarding reduced fetal movement. CONCLUSIONS Overall, the risk factors for adverse pregnancy outcomes differ between twin and singleton pregnancies. This highlights the need for further studies to examine the association between risk factors and adverse outcomes in twin pregnancies. The resulting data would facilitate tailored guidance for twin pregnancies, contribute to improved antenatal care, and inform wider public health strategies.
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Affiliation(s)
- Maya Whittaker
- Saint Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Isabelle Greatholder
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Mark D Kilby
- West Midlands Fetal Medicine Centre, Birmingham Women's and Children's Foundation Trust, Birmingham, UK
- Emeritus Professor of Fetal Medicine, College of Medical & Dental Sciences, University of Birmingham, Edgbaston, UK
- Illumina UK, Cambridge, UK
| | - Alexander E P Heazell
- Saint Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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O'Connor C, O'Connor E, Leitao S, Barrett S, O'Donoghue K. Clinical practice guidelines for the antenatal management of dichorionic diamniotic twin pregnancies: a systematic review. BMC Pregnancy Childbirth 2023; 23:347. [PMID: 37179347 PMCID: PMC10182673 DOI: 10.1186/s12884-023-05652-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023] Open
Abstract
OBJECTIVE This review aimed to identify guidelines with recommendations applicable to the antenatal management of dichorionic diamniotic twin pregnancies within high-income countries, appraise their methodological quality, and discuss the similarities and variability across guidelines. METHOD A systematic literature review of electronic databases was performed. Manual searches of guideline repositories and websites of professional organisations were performed to identify additional guidelines. The protocol for this systematic review was registered on PROSPERO (CRD42021248586, 25 June 2021). AGREE II and AGREE-REX tools were applied to assess the quality of eligible guidelines. A narrative and thematic synthesis described and compared the guidelines and their recommendations. RESULTS Twenty-four guidelines were included, from which 483 recommendations were identified across 4 international organisations and 12 countries. Guidelines addressed eight themes and recommendations were classified accordingly: chorionicity and dating (103 recommendations), fetal growth (105 recommendations), termination of pregnancy (12 recommendations), fetal death (13 recommendations), fetal anomalies (65 recommendations), antenatal care (65 recommendations), preterm labour (56 recommendations) and birth (54 recommendations). Guidelines showed significant variability in recommendations, with conflicting recommendations regarding non-invasive preterm testing, definitions surrounding selective fetal growth restriction, screening for preterm labour and the timing of birth. Guidelines lacked a focus on standard antenatal management of DCDA twins, management of discordant fetal anomaly and single fetal demise. CONCLUSIONS Specific guidance for dichorionic diamniotic twins is overall indistinct and access to guidance regarding the antenatal management of these pregnancies is currently difficult. Management of discordant fetal anomaly or single fetal demise needs greater consideration.
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Affiliation(s)
- Caroline O'Connor
- INFANT Research Centre, University College Cork, Cork, Ireland.
- Pregnancy Loss Research Group, Department of Obstetrics & Gynecology, University College Cork, Cork, Ireland.
- Department of Obstetrics and Gynecology, Cork University Maternity Hospital, 5th Floor, Wilton Road, Cork, Ireland.
| | - Emily O'Connor
- INFANT Research Centre, University College Cork, Cork, Ireland
- Pregnancy Loss Research Group, Department of Obstetrics & Gynecology, University College Cork, Cork, Ireland
- National Perinatal Epidemiology Center (NPEC), University College Cork, Cork, Ireland
| | - Sara Leitao
- Pregnancy Loss Research Group, Department of Obstetrics & Gynecology, University College Cork, Cork, Ireland
- National Perinatal Epidemiology Center (NPEC), University College Cork, Cork, Ireland
| | - Shauna Barrett
- Cork University Hospital Library, Cork University Hospital, Cork, Ireland
| | - Keelin O'Donoghue
- INFANT Research Centre, University College Cork, Cork, Ireland
- Pregnancy Loss Research Group, Department of Obstetrics & Gynecology, University College Cork, Cork, Ireland
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Cheung KW, Seto MTY, Wang W, Ng CT, To WWK, Ng EHY. Trend and causes of maternal death, stillbirth and neonatal death over seven decades in Hong Kong. THE LANCET REGIONAL HEALTH. WESTERN PACIFIC 2022; 26:100523. [PMID: 35833208 PMCID: PMC9272372 DOI: 10.1016/j.lanwpc.2022.100523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
BACKGROUND Reducing maternal and perinatal mortality is a global objective. Hong Kong is a city with low maternal and perinatal mortality but little is known about the trend and causes of these deaths in this high-income city. We analyzed the maternal death, stillbirth and neonatal death since 1946 in Hong Kong. METHODS Data were extracted from vital statistics, based on the number of registered deaths and births, provided by the Department of Health, the Government of the HKSAR. The annual change rate of mortality was evaluated by regression analysis. Contextual factors were collected to assess the association with mortality. FINDINGS Between 1946 and 2017, the stillbirth rate (per 1,000 total births) reduced from 21·5 to 2·4; early and late neonatal deaths (per 1,000 live births) reduced from 14·1 and 18·1 to 0·7 and 0·4 in 2017, respectively. The maternal mortality ratio (per 100,000 live births) declined from 125 to 1·8.The causes of maternal and perinatal deaths were available since 1981 and 1980 respectively. The leading causes of death were thromboembolism (37·0%) and obstetric haemorrhage (30·4%) for maternal death; congenital problem (30·1%) and prematurity (29·0%) for neonatal death. No data on causes of stillbirth were available. No specific shift of pattern was observed in the causes of maternal and neonatal death with time. There were no cases of maternal death due to sepsis and only 2 cases (2·2%) of maternal deaths due to indirect cause. INTERPRETATION The maternal and perinatal death have reduced significantly in Hong Kong and maintained at the lowest level globally. Indirect maternal death and sepsis were unusual causes of maternal deaths. Use of ICD-PM stillbirth classification, setting up a maternal death confidential enquiry and adding pregnancy checkbox could be the next step to identify and categorize hidden burden. FUNDING Nil.
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Affiliation(s)
- Ka Wang Cheung
- Department of Obstetrics and Gynaecology, Queen Mary Hospital, the University of Hong Kong, Hong Kong SAR, China
| | - Mimi Tin Yan Seto
- Department of Obstetrics and Gynaecology, Queen Mary Hospital, the University of Hong Kong, Hong Kong SAR, China
| | - Weilan Wang
- Department of Obstetrics and Gynaecology, Queen Mary Hospital, the University of Hong Kong, Hong Kong SAR, China
| | - Chi Tao Ng
- Clinical Trials Centre, The University of Hong Kong, Hong Kong SAR, China
| | - William Wing Kee To
- Department of Obstetrics and Gynaecology, United Christian Hospital, Hong Kong SAR, China
| | - Ernest Hung Yu Ng
- Department of Obstetrics and Gynaecology, Queen Mary Hospital, the University of Hong Kong, Hong Kong SAR, China
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Chen P, Li M, Mu Y, Wang Y, Liu Z, Li Q, Li X, Dai L, Xie Y, Liang J, Zhu J. Temporal trends and adverse perinatal outcomes of twin pregnancies at differing gestational ages: an observational study from China between 2012-2020. BMC Pregnancy Childbirth 2022; 22:467. [PMID: 35659606 PMCID: PMC9164484 DOI: 10.1186/s12884-022-04766-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 05/17/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND With the development of assisted reproductive technology, the twinning rate in China has been increasing. However, little is known about twinning from 2014 onwards. In addition, previous studies analysing optimal gestational times have rarely considered maternal health conditions. Therefore, whether maternal health conditions affect the optimal gestational time remains unclear. METHODS Data of women delivered between January 2012 and December 2020 were collected through China's National Maternal Near Miss Surveillance System. Interrupted time series analysis was used to determine the rates of twinning, stillbirth, smaller than gestational age (SGA), and low Apgar scores (< 4) among twins in China. To estimate the risk of each adverse perinatal outcome for separate gestational weeks, a multivariate generalised linear model was used. Infants born at 37 weeks of gestational age or foetuses staying in utero were used as reference separately. The analyses were adjusted for the sampling distribution of the population and the cluster effect at the hospital and individual levels were considered. RESULTS There were 442,268 infants enrolled in this study, and the adjusted rates for twinning, stillbirth, SGA, and low Apgar scores were 3.10%, 1.75%, 7.70%, and 0.79%, respectively. From 2012 to 2020, the twinning rate showed an increasing trend. Adverse perinatal outcomes, including stillbirth, SGA, and low Apgar scores showed a decreasing trend. A gestational age between 34 and 36 weeks decreased most for rate of stillbirth (average changing rate -9.72%, 95% confidence interval [CI] -11.41% to -8.00%); and a gestational age of between 37 and 38 weeks decreased most for rates of SGA (average changing rate -4.64%, 95% CI -5.42% to -3.85%) and low Apgar scores (average changing rate -17.61%, 95% CI -21.73% to -13.26%). No significant difference in changes in twinning rate or changes of each perinatal outcome was observed during periods of different fertility policies. Infants born at 37 weeks of gestation had a decreased risk of stillbirth, SGA, and low Apgar scores. Maternal antepartum or medical complications increased the risk of SGA and low Apgar scores in different gestational weeks. CONCLUSION China's twinning rate showed an increasing trend, while adverse perinatal outcomes decreased from 2012 to 2020. Fertility policy changes have had little effect on the twinning rate or the rate of adverse perinatal outcomes such as stillbirth, SGA, or low Apgar scores. The optimal gestational age for twins was 37 weeks. Women pregnant with twins and with antepartum or medical complications should be cautious due to an increased risk of SGA and low Apgar scores.
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Affiliation(s)
- Peiran Chen
- National Office for Maternal and Child Health Surveillance of China, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Mingrong Li
- National Office for Maternal and Child Health Surveillance of China, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yi Mu
- National Office for Maternal and Child Health Surveillance of China, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yanping Wang
- National Office for Maternal and Child Health Surveillance of China, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Zheng Liu
- National Office for Maternal and Child Health Surveillance of China, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Qi Li
- National Office for Maternal and Child Health Surveillance of China, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Xiaohong Li
- National Office for Maternal and Child Health Surveillance of China, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Li Dai
- National Office for Maternal and Child Health Surveillance of China, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
- Medical Big Data Center, Sichuan University, Chengdu, Sichuan, China
| | - Yanxia Xie
- National Office for Maternal and Child Health Surveillance of China, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China.
| | - Juan Liang
- National Office for Maternal and Child Health Surveillance of China, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China.
- Department of Obstetrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China.
| | - Jun Zhu
- National Office for Maternal and Child Health Surveillance of China, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, Sichuan, China
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10
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Khalil A, Giallongo E, Bhide A, Papageorghiou AT, Thilaganathan B. Reduction in twin stillbirth following implementation of NICE guidance. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2020; 56:566-571. [PMID: 32304623 DOI: 10.1002/uog.22051] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 03/23/2020] [Accepted: 04/06/2020] [Indexed: 06/11/2023]
Abstract
OBJECTIVE There has been an unprecedented fall in the rate of stillbirth in twin pregnancy in the UK. It is contested whether implementation of the National Institute for Health and Care Excellence (NICE) guidance on the antenatal management of uncomplicated twin pregnancies has contributed to this change. The aim of this study was to investigate whether the implementation of NICE guidance was associated with a reduction in the rate of stillbirth in twin pregnancies delivered in a large UK hospital. METHODS This was a retrospective cohort study including all twin pregnancies delivered at St George's Hospital, London, UK, between 2000 and 2018. Data were analyzed according to two time periods: before implementation of the NICE guidance on twins (before June 2013; pre-NICE) and after its implementation (after June 2013; post-NICE). The exclusion criteria were higher-order multiple gestations, pregnancies of unknown chorionicity, pregnancies complicated by miscarriage, those that underwent termination and those diagnosed with vanishing twin. The main outcome was stillbirth. Other outcomes included neonatal death (NND), admission to the neonatal intensive care unit (NICU) and emergency Cesarean section. We planned a priori a sensitivity analysis according to chorionicity. The chi-square test and Mann-Whitney U-test were used to compare outcomes between the study groups. RESULTS We included in the analysis 1666 twin pregnancies (3332 fetuses), of which 1114 pregnancies (2228 fetuses) were delivered before and 552 pregnancies (1104 fetuses) after June 2013. Of those, 1299 were dichorionic and 354 were monochorionic diamniotic. The incidence of stillbirth was significantly lower in the post-NICE than in the pre-NICE group (3.6 per 1000 births vs 13.5 per 1000 births; P = 0.008). The reduction in stillbirth rate was from 8.5 to 3.6 per 1000 births (P = 0.161) in dichorionic and from 33.6 to 3.8 per 1000 births (P = 0.011) in monochorionic diamniotic twin pregnancies. There was no significant difference in the rates of NND (P = 0.625), NICU admission (P = 0.506) or emergency Cesarean section (P = 0.820) between the two groups. The median gestational age at delivery was significantly lower in the post-NICE than in the pre-NICE group (median 36.3 vs 36.9 weeks; P < 0.001), as a consequence of a significant increase in preterm birth between 34 and 37 weeks' gestation (39.3% vs 27.0%; P = 0.002), but not before 34 weeks (P = 0.473). CONCLUSIONS A significant reduction of > 70% in the stillbirth rate in twin pregnancies was noted after implementation of the NICE guidance. This reduction was statistically significant in monochorionic, but not dichorionic, twin pregnancies. The improvement in twin pregnancy outcome was achieved without a concomitant increase in NND, admission to the NICU or emergency Cesarean section. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.
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Affiliation(s)
- A Khalil
- Fetal Medicine Unit, St George's University Hospitals NHS Foundation Trust, University of London, London, UK
- Vascular Biology Research Centre, Molecular and Clinical Sciences Research Institute, St George's University of London, London, UK
- Twins Trust Centre for Research and Clinical Excellence, St George's Hospital, London, UK
| | - E Giallongo
- Fetal Medicine Unit, St George's University Hospitals NHS Foundation Trust, University of London, London, UK
| | - A Bhide
- Fetal Medicine Unit, St George's University Hospitals NHS Foundation Trust, University of London, London, UK
| | - A T Papageorghiou
- Fetal Medicine Unit, St George's University Hospitals NHS Foundation Trust, University of London, London, UK
| | - B Thilaganathan
- Fetal Medicine Unit, St George's University Hospitals NHS Foundation Trust, University of London, London, UK
- Vascular Biology Research Centre, Molecular and Clinical Sciences Research Institute, St George's University of London, London, UK
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11
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Morris RK, Mackie F, Garces AT, Knight M, Kilby MD. The incidence, maternal, fetal and neonatal consequences of single intrauterine fetal death in monochorionic twins: A prospective observational UKOSS study. PLoS One 2020; 15:e0239477. [PMID: 32956426 PMCID: PMC7505445 DOI: 10.1371/journal.pone.0239477] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 09/07/2020] [Indexed: 12/01/2022] Open
Abstract
Objective Report maternal, fetal and neonatal complications associated with single intrauterine fetal death (sIUFD) in monochorionic twin pregnancies. Design Prospective observational study. Setting UK. Population 81 monochorionic twin pregnancies with sIUFD after 14 weeks gestation, irrespective of cause. Methods UKOSS reporters submitted data collection forms using data from hospital records. Main outcome measures Aetiology of sIUFD; surviving co-twin outcomes: perinatal mortality, central nervous system (CNS) imaging, gestation and mode of delivery, neonatal outcomes; post-mortem findings; maternal outcomes. Results The commonest aetiology was twin-twin transfusion syndrome (38/81, 47%), “spontaneous” sIUFD (22/81, 27%) was second commonest. Death of the co-twin was common (10/70, 14%). Preterm birth (<37 weeks gestation) was the commonest adverse outcome (77%): half were spontaneous and half iatrogenic. Only 46/75 (61%) cases had antenatal CNS imaging, of which 33 cases had known results of which 7/33 (21%) had radiological findings suggestive of neurological damage. Postnatal CNS imaging revealed an additional 7 babies with CNS abnormalities, all born at <36 weeks, including all 4 babies exhibiting abnormal CNS signs. Major maternal morbidity was relatively common, with 6% requiring ITU admission, all related to infection. Conclusions Monochorionic twin pregnancies with single IUD are complex and require specialist care. Further research is required regarding optimal gestation at delivery of the surviving co-twin, preterm birth prevention, and classifying the cause of death in twin pregnancies. Awareness of the importance of CNS imaging, and follow-up, needs improvement.
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Affiliation(s)
- R. Katie Morris
- Institute of Applied Health Research, University of Birmingham, Edgbaston, West Midlands, United Kingdom
- Fetal Medicine Centre, Birmingham Women’s and Children’s NHS Foundation Trust, Birmingham Women’s Hospital, Mindelsohn Way, Edgbaston, United Kingdom
- * E-mail:
| | - Fiona Mackie
- Institute of Metabolism and Systems Research, College of Medical & Dental Sciences, University of Birmingham, United Kingdom
| | - Aurelio Tobías Garces
- Institute of Metabolism and Systems Research, College of Medical & Dental Sciences, University of Birmingham, United Kingdom
| | - Marian Knight
- National Perinatal Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
| | - Mark D. Kilby
- Fetal Medicine Centre, Birmingham Women’s and Children’s NHS Foundation Trust, Birmingham Women’s Hospital, Mindelsohn Way, Edgbaston, United Kingdom
- Institute of Metabolism and Systems Research, College of Medical & Dental Sciences, University of Birmingham, United Kingdom
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12
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Cheung KW, Seto MTY, Wang W, Lai CWS, Kilby MD, Ng EHY. Effect of delayed interval delivery of remaining fetus(es) in multiple pregnancies on survival: a systematic review and meta-analysis. Am J Obstet Gynecol 2020; 222:306-319.e18. [PMID: 31394069 DOI: 10.1016/j.ajog.2019.07.046] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 07/22/2019] [Accepted: 07/30/2019] [Indexed: 11/18/2022]
Abstract
BACKGROUND The management of the pregnancy after delivery of the first fetus during a second-trimester miscarriage or very early preterm birth has not been well defined. OBJECTIVE The objective of the study was to evaluate whether delayed interval delivery of the remaining fetus(es) in twins/triplets is associated with improved survival, when compared with immediate delivery, after miscarriage or very preterm birth of the first fetus in multiple pregnancy. DATA SOURCES PubMed, MEDLINE, and Cochrane Library were systematically searched through January 2019. STUDY ELIGIBILITY CRITERIA (STUDY DESIGN, POPULATIONS, AND INTERVENTIONS): The following eligibility criteria applied: full-text original article; included at least 5 cases of delayed interval delivery for remaining fetus(es); and reported the survival rate of the first-born and the remaining fetus(es). STUDY APPRAISAL AND SYNTHESIS METHODS K.W.C. and W.W. searched, screened, and reviewed the articles. The quality of the studies was assessed according to the Strengthening the Reporting of Observational studies in Epidemiology checklist. If possible, data were stratified for assigned chorionicity. Effect sizes were pooled through a meta-analysis. RESULTS A total of 2295 published article and abstracts were identified. Only 16 studies met inclusion criteria. Meta-analysis of 492 pregnancies (432 twins [88%], 56 triplets [11%], 3 quadruplets and 1 quintuplets) showed that delayed interval delivery significantly improved the perinatal survival of remaining fetus(es) compared with the first born (odds ratio, 5.22, 95% confidence interval, 2.95-9.25, I2 = 53%), before 20+0 weeks (odds ratio, 6.32, 95% confidence interval, 1.99-20.13, I2 = 0%), between 20+0 and 23+6 weeks (odds ratio, 3.31, 95% confidence interval, 1.95-5.63, I2 = 0%), and after 24+0 weeks (odds ratio, 1.92, 95% confidence interval, 1.21-3.05, I2 = 0%), in dichorionic twin pregnancy (odds ratio, 14.89, 95% confidence interval, 6.19-35.84, I2 = 0%), and unselected triplet pregnancy (odds ratio, 2.33, 95% confidence interval, 1.02-5.32, I2 = 0%. ). Among the survivors, there were no significant differences in the short-term and long-term neonatal morbidities between the first-born and the remaining fetus(es). Serious maternal morbidity was reported in 39% of pregnancy after delayed interval delivery (71 of 183). In addition, 2 cases were managed by postpartum hysterectomy and 1 reported postoperative uterovaginal fistula. There were no recorded cases of maternal mortality. CONCLUSION Delayed interval delivery when a fetus has delivered in a multiple pregnancy is an effective management option to increase the survival rate of the remaining fetus(es). About 39% of women may experience morbidity following this management option.
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Affiliation(s)
- Ka Wang Cheung
- Department of Obstetrics and Gynecology, Queen Mary Hospital, University of Hong Kong, Hong Kong, China.
| | - Mimi Tin Yan Seto
- Department of Obstetrics and Gynecology, Queen Mary Hospital, University of Hong Kong, Hong Kong, China
| | - Weilan Wang
- Department of Obstetrics and Gynecology, Queen Mary Hospital, University of Hong Kong, Hong Kong, China
| | - Carman Wing Sze Lai
- Department of Obstetrics and Gynecology, Queen Mary Hospital, University of Hong Kong, Hong Kong, China
| | - Mark D Kilby
- Fetal Medicine Centre, Birmingham Women's and Children's Foundation Trust, Edgbaston, Birmingham, United Kingdom; Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Ernest Hung Yu Ng
- Department of Obstetrics and Gynecology, Queen Mary Hospital, University of Hong Kong, Hong Kong, China
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13
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Gibson JL, Castleman JS, Meher S, Kilby MD. Updated guidance for the management of twin and triplet pregnancies from the National Institute for Health and Care Excellence guidance, UK: What's new that may improve perinatal outcomes? Acta Obstet Gynecol Scand 2019; 99:147-152. [PMID: 31799724 DOI: 10.1111/aogs.13785] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 11/25/2019] [Indexed: 12/19/2022]
Abstract
In September 2019, NICE published updated guidance on the management of multiple pregnancy (NG 137). Many of the previous recommendations for care are upheld but there have been important changes: increased frequency of combined ultrasound/specialist antenatal care appointments for pregnancies containing a monochorionic placenta (twins and triplets), increased frequency of ultrasound monitoring in all triplet pregnancies, changes in the definition of selective growth restriction and its subsequent referral pathways, the introduction of some monitoring for twin (or triplet) anemia polycythemia sequence in monochorionic pregnancies (albeit in complex pregnancies or at an advanced stage), and a recommended timing of birth for any pregnancy with monoamniotic fetuses. New recommendations have been made for mode of delivery, fetal monitoring in labor, maternal analgesia, and the prevention of postpartum hemorrhage. The absence of any recommendation relating to the prevention of preterm birth is notable. The basis and implications of the updates that may improve perinatal outcomes are discussed.
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Affiliation(s)
- Janice L Gibson
- Ian Donald Fetal Medicine Centre, Queen Elizabeth University Hospital, Glasgow, UK
| | - James S Castleman
- West Midlands Fetal Medicine Centre, Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK
| | - Shireen Meher
- West Midlands Fetal Medicine Centre, Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK
| | - Mark D Kilby
- West Midlands Fetal Medicine Centre, Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK.,Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK
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14
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Austin K, Nassar N, Shand AW. Making sense of foetal growth: What is normal in twins? Paediatr Perinat Epidemiol 2019; 33:343-345. [PMID: 31531883 DOI: 10.1111/ppe.12586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 08/16/2019] [Indexed: 11/27/2022]
Affiliation(s)
- Kathryn Austin
- Department of Maternal Fetal Medicine, Royal Hospital for Women, Randwick, NSW, Australia.,Department of Maternal Fetal Medicine, Royal North Shore Hospital, St Leonards, NSW, Australia
| | - Natasha Nassar
- Child Population and Translational Health Research, Children's Hospital at Westmead Clinical School, The University of Sydney, Sydney, NSW, Australia
| | - Antonia W Shand
- Department of Maternal Fetal Medicine, Royal Hospital for Women, Randwick, NSW, Australia.,Department of Maternal Fetal Medicine, Royal North Shore Hospital, St Leonards, NSW, Australia.,Child Population and Translational Health Research, Children's Hospital at Westmead Clinical School, The University of Sydney, Sydney, NSW, Australia
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