Maternal "mirror" syndrome: Evaluating the benefits of fetal therapy.

OBJECTIVE: To evaluate maternal and perinatal outcomes following fetal intervention in the context of maternal "mirror" syndrome. STUDY DESIGN: A multicenter retrospective study of all cases of fetal hydrops complicated by maternal "mirror" syndrome and treated by any form of fetal therapy between 1995 and 2022. Medical records and ultrasound images of all cases were reviewed. "Mirror" syndrome was defined as fetal hydrops and/or placentomegaly associated with the maternal development of pronounced edema, with or without pre-eclampsia. Fetal hydrops was defined as the presence of abnormal fluid collections in ≥2 body cavities. RESULTS: Twenty-one pregnancies met the inclusion criteria. Causes of fetal hydrops and/or placentomegaly included fetal lung lesions (n = 9), twin-twin transfusion syndrome (n = 6), severe fetal anemia (n = 4), and others (n = 2). Mean gestational age at "mirror" presentation was 27.0 ± 3.8 weeks. Maternal "mirror" syndrome was identified following fetal therapeutic intervention in 14 cases (66.6%). "Mirror" symptoms resolved or significantly improved before delivery in 8 (38.1%) cases with a mean interval from fetal intervention to maternal recovery of 13.1 days (range 4-35). Three women needed to be delivered because of worsening "mirror" syndrome. Of the 21 pregnancies treated (27 fetuses), there were 15 (55.5%) livebirths, 7 (25.9%) neonatal deaths and 5 (18.5%) intra-uterine deaths. CONCLUSION: Following successful treatment and resolution of fetal hydrops, maternal "mirror" syndrome can improve or sometimes completely resolve before delivery. Furthermore, the recognition that "mirror" syndrome may arise only after fetal intervention necessitates hightened patient maternal surveillance in cases of fetal hydrops.

Feasibility of MRI assessment of maternal-fetal oxygen transport and consumption relative to maternal position in healthy late gestational pregnancies.

Late gestational supine positioning reduces maternal cardiac output due to inferior vena caval (IVC) compression, despite increased collateral venous return. However, little is known about the impact of maternal position on oxygen (O2 ) delivery and consumption of the gravid uterus, fetus, placenta and lower limbs. We studied the effects of maternal positioning on these parameters in 20 healthy pregnant subjects at 36 ± 2 weeks using magnetic resonance imaging (MRI); a follow-up MRI was performed 6-months postpartum (n = 16/20). MRI techniques included phase-contrast and T1/T2 relaxometry for blood flow and oximetry imaging, respectively. O2 transport was measured in the following vessels (bilateral where appropriate): maternal abdominal descending aorta (DAoabdo ), IVC, ovarian, paraspinal veins (PSV), uterine artery (UtA) and external iliacs, and umbilical. Maternal cardiac output was measured by summing DAothoracic and superior vena cava flows. Supine mothers (n = 6) had lower cardiac output and O2 delivery in the DAoabdo , UtA and external iliac arteries, and higher PSV flow than those in either the left (n = 8) or right (n = 6) lateral positions during MRI. However, O2 consumption in the gravid uterus, fetus, placenta and lower limbs was unaffected by maternal positioning. The ratio of IVC/PSV flow decreased in supine mothers while ovarian venous flow and O2 saturation were unaltered, suggesting a major route of pelvic venous return unaffected by maternal position. Placental-fetal O2 transport and consumption were similar between left and right lateral maternal positions. In comparison to non-pregnant findings, DAoabdo and UtA O2 delivery and pelvic O2 consumption increased, while lower-limb consumption remained constant , despite reduced external iliac artery O2 delivery in late gestation. KEY POINTS: Though sleeping supine during the third trimester is associated with an increased risk of antepartum stillbirth, the underlying biological mechanisms are not fully understood. Maternal cardiac output and uteroplacental flow are reduced in supine mothers due to inferior vena caval compression from the weight of the gravid uterus. This MRI study provides a comprehensive circulatory assessment, demonstrating reduced maternal cardiac output and O2 delivery (uteroplacental, lower body) in supine compared to lateral positioning; however, O2 consumption (gravid uterus, fetus, placenta, lower limbs) was preserved. Unlike other mammalian species, the ovarian veins conduct substantial venous return from the human pregnant uterus that is unaffected by maternal positioning. Lumbar paraspinal venous flow increased in supine mothers. These observations may have important considerations during major pelvic surgery in pregnancy (i.e. placenta percreta). Future studies should address the importance of maternal positioning as a potential tool to deliver improved perinatal outcomes in pregnancies with compromised uteroplacental O2 delivery.

Placenta Accreta Spectrum Disorders: A National Survey.

OBJECTIVES: Describe the current practice of Canadian obstetricians-gynaecologists in managing placenta accreta spectrum (PAS) disorders from suspicion of diagnosis to delivery planning and explore the impact of the latest national practice guidelines on this topic. METHODS: We distributed a cross-sectional bilingual electronic survey to Canadian obstetricians-gynaecologists in March-April 2021. Demographic data and information on screening, diagnosis, and management were collected using a 39-item questionnaire. The survey was validated and pretested among a sample population. Descriptive statistics were used to present the results. RESULTS: We received 142 responses. Almost 60% of respondents said they had read the latest Society of Obstetricians and Gynaecologists of Canada clinical practice guideline on PAS disorders, published in July 2019. Nearly 1 in 3 respondents changed their practice following this guideline. Respondents highlighted the importance of 4 key points: (1) limiting travel to thereby remain close to a regional care centre, (2) preoperative anemia optimization, (3) performance of cesarean-hysterectomy leaving the placenta in situ (83%), (4) access via midline laparotomy (65%). Most respondents recognized the importance of perioperative blood loss reduction strategies such as tranexamic acid and perioperative thromboprophylaxis via sequential compression devices and low-molecular-weight heparin until full mobilization. CONCLUSIONS: This study demonstrates the impact of the Society of Obstetricians and Gynaecologists of Canada's PAS clinical practice guideline on management choices made by Canadian clinicians. Our study highlights the value of a multidisciplinary approach to reducing maternal morbidity in individuals facing surgery for a PAS disorder and the importance of regionalized care that is resourced to provide maternal-fetal medicine and surgical expertise, transfusion medicine, and critical care support.

Comparison of circulating maternal placenta growth factor levels and sonographic evaluation of patients with abnormal first trimester screening analytes.

OBJECTIVE: To evaluate the role of mid-trimester placental growth factor (PlGF) in patients with abnormal circulating levels of first-trimester biomarkers. METHODS: Retrospective cohort study including singleton pregnancies complicated by abnormal first-trimester biomarkers (2017-2020). Pregnancies complicated with chromosomal/structural anomalies were excluded. All patients had ultrasound imaging including uterine artery Doppler combined with measurement of maternal circulating PlGF. Sonographic findings, maternal and perinatal outcomes, and placental histopathology were compared between pregnancies with normal and low (<10th percentile for gestational age) PlGF levels. The diagnostic accuracy of PlGF for the prediction of specific placental-mediated complications was compared with the uterine artery Doppler assessment and additional sonographic findings. RESULTS: Seventy-one pregnancies were assessed, of which 35 (49.3%) had low PlGF levels. Maternal sociodemographic characteristics, nulliparity, and aspirin consumption were comparable. In comparison with patients with normal PlGF levels, individuals with low PlGF levels had a higher rate of fetal growth restriction (EFW <3rd centile; 42.9% vs. 8.3%, p = 0.001), preterm-preeclampsia (22.9% vs. 0%, p = 0.002), preterm delivery <34 weeks (54.3% vs. 8.3%, p < 0.001) and maternal vascular malperfusion placental pathology (72.7% vs. 21.7%, p < 0.001) following delivery. Adjusting for uterine artery Doppler and fetal biometry status, mid-trimester low PlGF remained significantly associated with these placental-mediated complications. The predictive capacity of PlGF outperformed ultrasound imaging with only minimal diagnostic improvement when ultrasound information was combined with PlGF status. CONCLUSION: In pregnancies with unexplained abnormal first-trimester biomarkers, mid-trimester PlGF outperformed a comprehensive ultrasound assessment in the identification of a subset of patients destined to develop placental dysfunction. This blood test may be an alternative initial approach in this context, especially where access to specialist care is more geographically challenging.

Intravenous immunoglobulin in the management of severe early onset red blood cell alloimmunisation.

Our objective was to assess the effect of maternal intravenous immunoglobulin (IVIG) administration for severe red blood cell (RBC) alloimmunisation on fetal outcomes. This is a case-control study. Women with a history of severe early onset alloimmunisation resulting in fetal loss in a previous pregnancy and high anti-D or anti-K antibody titres received IVIG in a subsequent pregnancy. We assessed gestational age at first transfusion and fetal outcomes in the subsequent pregnancy and compared these with the outcomes in the previous pregnancy. The most responsible antibody was anti-D in 17 women and anti-K in two others, whilst seven had more than one antibody. In all, 19 women received IVIG in 22 pregnancies, two of which did not even need an intrauterine transfusion (IUT). For previous early losses despite transfusion, IVIG was associated with a relative increase in fetal haemoglobin between treated and untreated pregnancies of 36.5 g/L (95% confidence interval 19.8-53.2, p = 0.0013) and improved perinatal survival (eight of eight vs. none of six, p = 0.001). For previous losses at <20 weeks, it enabled first transfusion deferral in subsequent pregnancies to at least 19.9 weeks (mean 23.2 weeks). Overall, IVIG decreases the severity of haemolytic disease of the fetus and newborn and allows deferral of the first IUT to a safer gestation in severe early-onset RBC alloimmunisation and rarely may even avoid the need for IUT entirely.

Diagnostic utility of serial circulating placental growth factor levels and uterine artery Doppler waveforms in diagnosing underlying placental diseases in pregnancies at high risk of placental dysfunction.

BACKGROUND: Placental pathology assessment following delivery in pregnancies complicated by preeclampsia, fetal growth restriction, abruption, and stillbirth reveals a range of underlying diseases. The most common pathology is maternal vascular malperfusion, characterized by high-resistance uterine artery Doppler waveforms and abnormal expression of circulating maternal angiogenic growth factors. Rare placental diseases (massive perivillous fibrinoid deposition and chronic histiocytic intervillositis) are reported to have high recurrence risks, but their associations with uterine artery Doppler waveforms and angiogenic growth factors are presently ill-defined. OBJECTIVE: To characterize the patterns of serial placental growth factor measurements and uterine artery Doppler waveform assessments in pregnancies that develop specific types of placental pathology to gain insight into their relationships with the timing of disease onset and pregnancy outcomes. STUDY DESIGN: A retrospective cohort study conducted between January 2017 and November 2021 included all singleton pregnancies with at least 1 measurement of maternal circulating placental growth factor between 16 and 36 weeks' gestation, delivery at our institution, and placental pathology analysis demonstrating diagnostic features of maternal vascular malperfusion, fetal vascular malperfusion, villitis of unknown etiology, chronic histiocytic intervillositis, or massive perivillous fibrinoid deposition. Profiles of circulating placental growth factor as gestational age advanced were compared between these placental pathologies. Maternal and perinatal outcomes were recorded. RESULTS: A total of 337 pregnancies from 329 individuals met our inclusion criteria. These comprised placental pathology diagnoses of maternal vascular malperfusion (n=109), fetal vascular malperfusion (n=87), villitis of unknown etiology (n=96), chronic histiocytic intervillositis (n=16), and massive perivillous fibrinoid deposition (n=29). Among patients who developed maternal vascular malperfusion, placental growth factor levels gradually declined as pregnancy progressed (placental growth factor <10th percentile at 16-20 weeks' gestation in 42.9%; 20-24 weeks in 61.9%; 24-28 weeks in 77%; and 28-32 weeks in 81.4%) accompanied by mean uterine artery Doppler pulsatility index >95th percentile in 71.6% cases. Patients who developed either fetal vascular malperfusion or villitis of unknown etiology mostly exhibited normal circulating placental growth factor values in association with normal uterine artery Doppler waveforms (mean [standard deviation] pulsatility index values: fetal vascular malperfusion, 1.14 [0.49]; villitis of unknown etiology, 1.13 [0.45]). Patients who developed either chronic histiocytic intervillositis or massive perivillous fibrinoid deposition exhibited persistently low placental growth factor levels from the early second trimester (placental growth factor <10th centile at 16-20 weeks' gestation in 80% and 77.8%, respectively; 20-24 weeks in 88.9% and 63.6%; 24-28 weeks in 85.7% and 75%), all in combination with normal uterine artery Doppler waveforms (mean pulsatility index >95th centile: chronic histiocytic intervillositis, 25%; massive perivillous fibrinoid deposition, 37.9%). Preeclampsia developed in 83 of 337 (24.6%) patients and was most common in those developing maternal vascular malperfusion (54/109, 49.5%) followed by chronic histiocytic intervillositis (7/16, 43.8%). There were 29 stillbirths in the cohort (maternal vascular malperfusion, n=10 [9.2%]; fetal vascular malperfusion, n=5 [5.7%]; villitis of unknown etiology, n=1 [1.0%]; chronic histiocytic intervillositis, n=7 [43.8%]; massive perivillous fibrinoid deposition, n=6 [20.7%]). Most patients experiencing stillbirth exhibited normal uterine artery Doppler waveforms (21/29, 72.4%) and had nonmaternal vascular malperfusion pathologies (19/29, 65.5%). By contrast, 28 of 29 (96.5%) patients experiencing stillbirth had ≥1 low placental growth factor values before fetal death. CONCLUSION: Serial circulating maternal placental growth factor tests, in combination with uterine artery Doppler waveform assessments in the second trimester, may indicate the likely underlying type of placental pathology mediating severe adverse perinatal events. This approach has the potential to test disease-specific therapeutic strategies to improve clinical outcomes. Serial placental growth factor testing, compared with uterine artery Doppler studies, identifies a greater proportion of patients destined to have a poor perinatal outcome because diseases other than maternal vascular malperfusion are characterized by normal uteroplacental circulation.

Development of a Training Model for Teaching Intrauterine Fetal Blood Transfusion.

This article describes an inexpensive simulator developed for teaching intrauterine blood transfusion. The model is constructed from a boneless chicken thigh folded over a Penrose drain placed in a water-filled snap-lock lid container and covered by melted ballistic gel to simulate the fetal intrahepatic vessel. Participants valued this educational tool and reported feeling the model was practical and realistic. This low-cost, high-fidelity model provides realistic tissue resistance and represents a sonographically accurate intrahepatic fetal blood transfusion training tool.

Improving Early Pregnancy Screening for Placenta Accreta Spectrum: Retrospective Analysis of Early Screening Candidates by Risk Assessment in Canada.

Early screening for placenta accreta spectrum (PAS) is not established in Canada, yet has been demonstrated with a 2-stage strategy in patients classified as at risk at the nuchal translucency examination. We performed a retrospective analysis of women with singleton pregnancies who had first-trimester screening and subsequently had a pathology-confirmed PAS. We sought those who met high-risk clinical criteria for PAS: previous uterine surgeries and an anterior low-lying placenta. Over 80% of women met both high-risk criteria at the nuchal translucency examination. Lack of early recognition and risk stratification resulted in a late median gestational age at suspicion and diagnosis of PAS.

Outcomes in emergency versus electively scheduled cases of placenta accreta spectrum disorder managed by cesarean-hysterectomy within a multidisciplinary care team.

OBJECTIVE: Compare maternal and perinatal outcomes between emergency and electively scheduled cesarean-hysterectomy for placenta accreta spectrum (PAS) disorders. METHOD: Single-center retrospective cohort study including 125 cases of antenatally suspected and pathologically confirmed PAS disorders. Maternal and perinatal outcomes were analyzed. Multivariate logistic regression was used to test associations. Survival curves exploring risk factors for emergency birth were sought. RESULTS: 25 (20%) and 100 (80%) patients had emergency and electively scheduled birth, respectively. Emergency birth had a higher estimated blood loss (2772 [2256.75] vs. 1561.19 [1152.95], P < 0.001), with a higher rate of coagulopathy (40% vs. 6%; P < 0.001) and bladder injury (44% vs. 13%; P < 0.001); and was associated with increased rates of blood transfusion (aOR 4.9, CI95% 1.3-17.5, P = 0.01), coagulopathy (aOR 16.4, CI95% 2.6-101.4, P = 0.002) and urinary tract injury (aOR 6.96, CI95% 1.5-30.7, P = 0.01). Gestational age at birth was lower in the emergency group (31.55 [4.75] vs. 35.19 [2.77], P = 0.001), no difference in perinatal mortality was found. A sonographically short cervix and/or history of APH had an increased cumulative risk of emergency birth with advancing gestational age. CONCLUSION: Patients with PAS disorders managed in a tertiary center by a multidisciplinary team requiring emergency birth have increased maternal morbidity and poorer perinatal outcomes than those with electively scheduled birth.

Identification of Essential Steps in Outlet Forceps-Assisted Vaginal Delivery: A Delphi Study.

OBJECTIVE: To achieve expert consensus using the Delphi methodology on the sub-steps considered essential in an outlet forceps-assisted vaginal delivery (FAVD). The purpose of this work is to help inform a framework for standardized training and objective assessment in the procedure. METHODS: A Delphi survey was conducted with an international panel of experts in FAVD. Using an online platform, experts rated sub-steps of FAVD on a 5-point Likert scale to indicate whether they considered them essential. Responses were returned to the panel until consensus was reached (Cronbach α ≥ 0.80) with an intraclass correlation coefficient ≥0.75. All sub-steps with a rate of agreement ≥80% are proposed to be included in a future evaluation instrument. RESULTS: After the first iteration of the Delphi procedure, a response rate of 42% was reached (n = 21); the second iteration was only sent to those who had participated in the initial iteration, reaching a response rate of 100%. Of 42 sub-steps rated in the first round, 24 (57.1%) achieved consensus, 8 (19%) were rejected, and 10 (23.8%) were re-rated in the second round. After 2 iterations, 28 sub-steps were agreed upon by the experts to be essential in FAVD. CONCLUSIONS: A panel of experts identified a total of 28 sub-steps essential to FAVD. This list could inform the development of an objective assessment framework and evaluation tool for this procedure. Further research should focus on the standardization, applicability, validation, and introduction of this tool in medical training, with a focus on real-life, high-fidelity simulation and online educational tools.

Outcome predictors for maternal red blood cell alloimmunisation with anti-K and anti-D managed with intrauterine blood transfusion.

Red blood cell (RBC) alloimmunisation with anti-D and anti-K comprise the majority of cases of fetal haemolytic disease requiring intrauterine red cell transfusion (IUT). Few studies have investigated which haematological parameters can predict adverse fetal or neonatal outcomes. The aim of the present study was to identify predictors of adverse outcome, including preterm birth, intrauterine fetal demise (IUFD), neonatal death (NND) and/or neonatal transfusion. We reviewed the records of all pregnancies alloimmunised with anti-K and anti-D, requiring IUT over 27 years at a quaternary fetal centre. We reviewed data for 128 pregnancies in 116 women undergoing 425 IUTs. The median gestational age (GA) at first IUT was significantly earlier for anti-K than for anti-D (24·3 vs. 28·7 weeks, P = 0·004). Women with anti-K required more IUTs than women with anti-D (3·84 vs. 3·12 mean IUTs, P = 0·036) and the fetal haemoglobin (Hb) at first IUT was significantly lower (51.0 vs. 70.5 g/l, P = 0·001). The mean estimated daily decrease in Hb did not differ between the two groups. A greater number of IUTs and a slower daily decrease in Hb (g/l/day) between first and second IUTs were predictive of a longer period in utero. Earlier GA at first IUT and a shorter interval from the first IUT until delivery predicted IUFD/NND. Earlier GA and lower Hb at first IUT significantly predicted need for phototherapy and/or blood product use in the neonate. In the anti-K group, a greater number of IUTs was required in women with a higher titre. Furthermore, the higher the titre, the earlier the GA at which an IUT was required in both groups. The rate of fall in fetal Hb between IUTs decreased, as the number of transfusions increased. Our present study identified pregnancies at considerable risk of an unfavourable outcome with anti-D and anti-K RBC alloimmunisation. Identifying such patients can guide pregnancy management, facilitates patient counselling, and can optimise resource use. Prospective studies can also incorporate these characteristics, in addition to laboratory markers, to further identify and improve the outcomes of these pregnancies.

Safer outcomes for placenta accreta spectrum disorders: A decade of quality improvement.

OBJECTIVE: To describe the evolution and evaluation of protocol-based multidisciplinary quality improvement (QI) in women undergoing cesarean hysterectomy for radiologically suspected and pathologically confirmed placenta accreta spectrum (PAS) disorders. METHODS: A single-center, retrospective cohort study was conducted of all patients undergoing cesarean hysterectomy for PAS disorders between March 2009 and June 2018. Two distinct periods were defined to compare outcomes: 2009-2011 (initial period) and 2017-2018 (current period). Primary outcomes included blood loss and administration of blood products. Secondary outcomes included perioperative levels of hemoglobin, adverse events and complications, time to mobilization, and length of hospitalization. RESULTS: Among the 105 consecutive patients identified, there were 26 in the initial period and 32 in the current period. With the implementation of all QI care bundles, median estimated surgical blood loss halved from 2000 ml in the initial period to 1000 ml in the current period, and fewer patients required allogenic blood transfusion (61.5% vs 25%). Patients in the current period demonstrated improved postoperative levels of hemoglobin compared to those in the initial period (101 g/L vs 89 g/L) and had a shorter median postoperative hospital stay (3 days vs 5 days). CONCLUSION: These results support the implementation of a multifaceted QI and patient care initiative for women with PAS disorders.

Circulating maternal placental growth factor responses to low-molecular-weight heparin in pregnant patients at risk of placental dysfunction.

BACKGROUND: Patients at high risk of severe preeclampsia and fetal growth restriction have low circulating levels of placental growth factor and features of maternal vascular malperfusion placental pathology at delivery. Multimodal screening and commencement of aspirin prophylaxis at 11 to 13 weeks' gestation markedly reduces the risk of preterm delivery with preeclampsia. However, the additional role of low-molecular-weight heparin and mechanisms of action remain uncertain. Because low-molecular-weight heparin augments the production and release of placental growth factor in vitro by both placental villi and vascular endothelium, it may be effective to suppress the risk of severe preeclampsia in a niche group of high-risk patients with low circulating placental growth factor in the early second trimester. OBJECTIVE: This study aimed to define a gestational age-specific reference range for placental growth factor and to test the hypothesis that prophylactic low-molecular-weight heparin administered in the early second trimester may restore deficient circulating placental growth factor levels and thereby prolong pregnancy. STUDY DESIGN: Centile curves for circulating placental growth factor levels from 12 to 36 weeks' gestation were derived using quantile regression of combined data from a published cohort of 4207 unselected nulliparous patients in Cambridge, United Kingdom, at 4 sampling time points (12, 20, 28, and 36 weeks' gestation) and the White majority (n=531) of a healthy nulliparous cohort in Toronto, Canada, at 16 weeks' gestation using the same test platform. Within a specialty high-risk clinic in Toronto, a niche group of 7 patients with a circulating placental growth factor at the <10th centile in the early second trimester received daily prophylactic low-molecular-weight heparin (enoxaparin; 40 mg subcutaneously) and were followed up until delivery (group 1). Their baseline characteristics, delivery details, and placental pathologies were compared with 5 similar patients who did not receive low-molecular-weight heparin during the observation period (group 2) and further with 21 patients who delivered with severe preeclampsia (group 3) in the same institution. RESULTS: A gestational age-specific reference range for placental growth factor levels at weekly intervals between 12 and 36 weeks was established for White women with singleton pregnancies. Within group 1, 5 of 7 patients demonstrated a sustained increase in circulating placental growth factor levels, whereas placental growth factor levels did not increase in group 2 or group 3 patients who did not receive low-molecular-weight heparin. Group 1 patients receiving low-molecular-weight heparin therapy exhibited a later gestation at delivery, relative to groups 2 and 3 (36 weeks [33-37] vs 23 weeks [22-26] and 28 weeks [27-31], respectively), and consequently had higher birthweights (1.93 kg [1.1-2.7] vs 0.32 kg [0.19-0.39] and 0.73 kg [0.52-1.03], respectively). The incidence of stillbirth was lowest in group 1 (14% [1 of 7]), relative to groups 2 and 3 (80% [4 of 5] and 29% [6 of 21], respectively). Maternal vascular malperfusion was the most common placental pathology found in association with abnormal uterine artery Doppler. CONCLUSION: In patients at high risk of a serious adverse pregnancy outcome owing to placental disease, the addition of low-molecular-weight heparin to aspirin prophylaxis in the early second trimester may restore deficient circulating placental growth factor to mediate an improved perinatal outcome. These data support the implementation of a multicenter pilot randomized control trial where patients are recruited primarily based on the assessment of placental function in the early second trimester.

Monochorionic monoamniotic twin pregnancies.

Monoamniotic twin pregnancies are rare, but early diagnosis of such pregnancies is critical, as the incidence of complications in these pregnancies is much higher than in diamniotic or dichorionic twin pregnancies. Overall, only 70% of all monoamniotic twins will survive. Furthermore, approximately half of fetal deaths in these pregnancies are because of the high incidence of fetal anomalies (15%-25%), such as twin reversed arterial perfusion sequence and conjoined twinning. Therefore, early anatomy screening in the first trimester of pregnancy is recommended. Other causes of fetal death in these pregnancies include twin-twin transfusion syndrome, tight cord entanglement, or acute hemodynamic imbalances through the large placental vascular anastomoses. After viability, fetal surveillance can be intensified, as this decreases the risk of in utero death. Both inpatient and outpatient surveillance are reasonable. If otherwise uncomplicated, monoamniotic twins should be delivered at 33 to 34 weeks' gestation. Most centers will deliver by cesarean delivery, but some continue to advocate for vaginal delivery. Lastly, neonatal morbidity is high in monoamniotic twin pregnancies and is mainly related to prematurity.

Consensus on Training and Assessment of Competence in Performing Chorionic Villus Sampling and Amniocentesis: An International Delphi Survey.

INTRODUCTION: The aim of this study was to obtain expert consensus on the content of a curriculum for learning chorionic villus sampling (CVS) and amniocentesis (AC) and the items of an assessment tool to evaluate CVS and AC competence. METHODS: We used a 3-round iterative Delphi process. A steering committee supervised all processes. Seven international collaborators were identified to expand the breadth of the study internationally. The collaborators invited fetal medicine experts to participate as panelists. In the first round, the panelists suggested content for a CVS/AC curriculum and an assessment tool. The steering committee organized and condensed the suggested items and presented them to the panelists in round 2. In the second round, the panelists rated and commented on the suggested items. The results were processed by the steering committee and presented to the panelists in the third round, where final consensus was obtained. Consensus was defined as support by more than 80% of the panelists for an item. RESULTS: Eighty-six experts agreed to participate in the study. The panelists represented 16 countries across 4 continents. The final list of curricular content included 12 theoretical and practical items. The final assessment tool included 11 items, systematically divided into 5 categories: pre-procedure, procedure, post-procedure, nontechnical skills, and overall performance. These items were provided with behavioral scale anchors to rate performance, and an entrustment scale was used for the final overall assessment. CONCLUSION: We established consensus among international fetal medicine experts on content to be included in a CVS/AC curriculum and on an assessment tool to evaluate CVS/AC skills. These results are important to help transition current training and assessment methods from a time- and volume-based approach to a competency-based approach which is a key step in improving patient safety and outcomes for the 2 most common invasive procedures in fetal medicine.