Greg Ryan

Mount Sinai Hospital, Toronto · Department of Fetal Medicine

Objectif: Cette directive clinique passe en revue les données probantes sur la prise en charge de la grossesse gémellaire monochoriale normale et compliquée. Population cible: Les femmes menant une grossesse gémellaire ou multiple de haut rang. BéNéFICES, RISQUES ET COûTS: L'application des recommandations de cette directive devrait améliorer la...

Low blood flow through the fetal left heart is often conjectured as an etiology for hypoplastic left heart syndrome (HLHS). To investigate if a decrease in left heart flow results in growth failure, we generate left ventricular inflow obstruction (LVIO) in mid-gestation fetal lambs by implanting coils in their left atrium using an ultrasound-guided...

Background: Twin gestations are associated with an increased risk of pregnancy complications. However, high-quality evidence regarding the management of twin pregnancies is limited, often resulting in inconsistencies in the recommendations of various national and international professional societies. In addition, some recommendations related to th...

OSCEs are a familiar component of postgraduate examinations worldwide, simulating clinical scenarios to assess a candidate's clinical skills and a range of competencies. This book will combine comprehensive knowledge and evidence-based practice standards in obstetrics and medical complications of pregnancy into a patient-centered approach using sta...

(Obstet Gynecol. 2022;139:1027–1042. doi: 10.1097/AOG.0000000000004793) Fetal therapy carries both benefits and extensive risks for the fetus and pregnant patient. As such, outlines created by several different groups and organizations are used throughout the country, but these general guidelines do not anticipate the needs of individual circumstan...

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 re...

Fetal therapies undertaken to improve fetal outcome or to optimize transition to neonate life often entail some level of maternal, fetal, or neonatal risk. A fetal therapy center needs access to resources to carry out such therapies and to manage maternal, fetal, and neonatal complications that might arise, either related to the therapy per se or a...

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...

Objective Pregnancies complicated by fetal heart defects often undergo a planned delivery prior to term by either induction of labour or cesarean delivery to ensure optimal availability of neonatal care. We aimed to assess whether such planned deliveries achieve their goal of better perinatal care. Methods We conducted a retrospective case-control...

( Engl J Med . 2021;385:107–118) Congenital diaphragmatic hernia (CDH) can lead to serious lifelong complications, but may be treated if diagnosed before birth. In fetoscopic endoluminal tracheal occlusion (FETO), a balloon is inserted into the fetal trachea in utero to stimulate fetal lung growth and is removed prior to birth. One study of 210 fet...

Background The provision of care to pregnant persons and neonates must continue through pandemics. To maintain quality of care, while minimizing physical contact during the Severe Acute Respiratory Syndrome-related Coronavirus-2 (SARS-CoV2) pandemic, hospitals and international organizations issued recommendations on maternity and neonatal care del...

Background Complete atrioventricular block (CAVB) is a complication of maternal antibody positivity and treatment of fetal disease is controversial in terms of efficacy and safety. We hypothesized that dexamethasone treatment for fetal anti-Ro/SSA antibody-mediated cardiac disease leads to better pregnancy outcomes than expectant management. Metho...

Objective: Monochorionic pregnancies are at increased risk of single intrauterine death (sIUD) and subsequent brain injury in the survivor due to shared placentation. We assessed the association between middle cerebral artery peak systolic velocity (MCA PSV) and cerebral injury on magnetic resonance imaging (MRI) and characterized the association...

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 ou...

(Abstracted from N Engl J Med 2021;385:107–118) Congenital diaphragmatic hernia (CDH) occurs in approximately 1 in 4000 births, and 85% of these cases have the defect on the left side. The condition is associated with neonatal death due to respiratory failure and pulmonary hypertension.

OBJECTIVE: We report the outcome of pregnancies treated with intravenous immunoglobulin (IVIG) for severe red blood cell alloimmunization, evaluating whether IVIG defers the development of severe fetal anaemia and its consequences. BACKGROUND: Although fetal anemia can be treated very successfully with intrauterine transfusion (IUT), procedures be...

Background Two randomized controlled trials compared the neonatal and infant outcomes after fetoscopic endoluminal tracheal occlusion (FETO) with expectant prenatal management in fetuses with moderate and severe isolated congenital diaphragmatic hernia (CDH), respectively. FETO was carried out at 27⁺⁰ to 29⁺⁶ weeks’ gestation (referred to as “early...

Monoamniotic twins are rare, but their early diagnosis 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. About half of the fetal deaths is due to the high incidence of fetal anomalies (15-25%), twin reversed...

Background Observational studies have shown that fetoscopic endoluminal tracheal occlusion (FETO) has been associated with increased survival among infants with severe pulmonary hypoplasia due to isolated congenital diaphragmatic hernia on the left side, but data from randomized trials are lacking. Methods In this open-label trial conducted at cen...

The cover image is based on the Original Article Prenatally diagnosed omphaloceles: Report of 92 cases and association with Beckwith‐Wiedemann syndrome by Nimrah Abbasi et al., https://doi.org/10.1002/pd.5930.

Objective: Fetal thoraco-amniotic shunts (TASs) can dislodge in utero, migrating internally into the fetal thorax or externally into the amniotic cavity. Our objective was to evaluate the perinatal and long-term outcome of fetuses with TAS dislodgement and conduct a review of the literature. Methods: This is a retrospective review of all TAS ins...

Objective: To evaluate inter-rater agreement for sonographic classification of stomach position (as a surrogate for liver herniation) in fetal left congenital diaphragmatic hernia (LCDH) among: (i) fetal medicine specialists from the North American Fetal Therapy Network (NAFTNet) centres within and without the Fetal Endoscopic Tracheal Occlusion (...

Objective: Describe the prevalence, perinatal and long-term outcomes of Beckwith-Wiedemann syndrome (BWS) among prenatally detected omphaloceles. Methods: All prenatally diagnosed omphaloceles from 2010 to 2015 within a single tertiary care centre were identified. An echocardiogram and detailed fetal ultrasound were performed, and amniocentesis...

Key Points/Highlights We have developed a high‐fidelity interactive “video‐game” simulator in order to teach fetoscopic laser ablation of placental anastomoses for twin‐twin transfusion syndrome This simulator may be used by teachers in order to provide metrics‐based simulator education to multiple trainees, in both hands‐on and distanced learning...

Key Points What's already known about this topic? Fetal lymphatic malformations (LMs) can be detected on prenatal ultrasound and until recently, therapeutic options were limited. Recently the mammalian target of rapamycin inhibitor rapamycin has emerged as a safe, effective therapy for children with LMs and multiple studies have demonstrated impro...

Monochorionic monoamniotic multiple pregnancies are characterized by the presence of multiple fetuses sharing a single placenta and a single amniotic cavity. Early diagnosis of chorionicity and amnionicity is critical as complication rates are significantly higher in monoamniotic twins than in diamniotic twins. Although the perinatal mortality of m...

Introduction: Prenatal work-up for congenital diaphragmatic hernia (CDH) is important for risk stratification, standardization, counseling, and optimal therapeutic choice. To determine current practice patterns regarding prenatal CDH work-up, including prenatal ultrasound and magnetic resonance imaging (MRI) use, and to identify areas for standard...

Background: The rhesus (Rh) and Kell blood group systems are the most common of over 50 different antigens capable of causing maternal red blood cell (RBC) alloimmunization and severe fetal hemolytic disease. Anti-K and anti-D are responsible for a significant proportion of fetal anemia requiring intrauterine transfusion (IUT). Whilst IUT of packed...

Objective Fetal myelomeningocele closure results in better infant outcomes than postnatal closure at the cost of potential prematurity and maternal morbidity. Our aim is to describe the setup of a fetal myelomeningocele closure program in Canada and document its outcomes. Methods We conducted a retrospective review of all open fetal myelomeningoce...

Objectives: In fetal congenital complete heart block, the slow fetal heart rate prolongs the diastolic phase of the cardiac cycle, which may affect Doppler measurements that are typically used to quantify placental function. We here describe the umbilical artery (UA) and middle cerebral artery (MCA) Dopplers in a cohort of fetuses with heart block...

Objective: To compare perinatal outcomes associated with three methods of selective reduction in complicated monochorionic (MC) twin pregnancies: bipolar cord coagulation (BC), fetoscopic or ultrasound guided laser cord occlusion and radiofrequency ablation (RFA). Methods: Retrospective cohort study of complicated MC twin pregnancies undergoing...

Glutamine synthetase (GS) is the enzyme responsible for the biosynthesis of glutamine, providing the only source of endogenous glutamine necessary for several critical metabolic and developmental pathways. Glutamine synthetase (GS) deficiency, caused by pathogenic variants in the glutamate-ammonia ligase (GLUL) gene, is a rare autosomal recessive i...

Background: Open spina bifida (OSB) is one of the most common congenital central nervous system defects and leads to long-term physical and cognitive disabilities. Open fetal surgery for OSB improves neurological outcomes and reduces the need for ventriculoperitoneal shunting, compared to postnatal surgery, but is associated with a significant ris...

Worldwide, about 150 000 infants are born with spina bifida yearly, making this condition one of the most common fetal central nervous system anomalies compatible with life. Over the last decade, major changes have been introduced in the prenatal diagnosis and management of spina bifida. In this review, we provide a brief summary of the current man...

Objectives With improved access to intrauterine transfusion (IUT), more fetuses with haemoglobin Bart’s hydrops fetalis (HBHF; homozygous α ⁰ -thalassaemia) will survive. Design To evaluate the long-term outcomes of affected fetuses with and without IUT in Ontario, Canada, we retrospectively collected data on IUTs and pregnancy outcomes in all cas...

Purpose To describe the postnatal outcome of fetal meconium peritonitis and identify prenatal predictors of neonatal surgery. Methods We retrospectively reviewed all fetuses with ultrasound findings suspicious for meconium peritonitis at a single center over a 10-year period. A systematic review and meta-analysis were then performed pooling our res...

View Supplementary Video 1 Laryngoscope, 2020

Objective: In gastroschisis, there is evidence to suggest that gut dysfunction develops secondary to bowel inflammation; we aimed to evaluate the effect of maternal antenatal corticosteroids administered for obstetric reasons on time to full enteral feeds in a multicenter cohort study of gastroschisis infants. Methods: A three center, retrospect...

The COVID-19 pandemic has stressed patients and healthcare givers alike and challenged our practice of antenatal care, including fetal diagnosis and therapy. This document aims to review relevant recent information to allow us to optimize prenatal care delivery. We discuss potential modifications to obstetric management and fetal procedures in SARS...

Even though the global COVID‐19 pandemic may affect how medical care is delivered in general, most countries try to maintain steady access for women to routine pregnancy care, including fetal anomaly screening. This means that, also during this pandemic, fetal anomalies will be detected, and that discussions regarding invasive genetic testing and p...

Objective: Septo-optic dysplasia (SOD) is a clinical syndrome characterized by varying combinations of optic nerve hypoplasia, pituitary gland hypoplasia and abnormal cavum septum pellucidum. It is suspected on prenatal imaging when there is non-visualization or hypoplasia of the septal leaflets. Long-term postnatal outcomes of fetuses with prenat...

Fetal cardiac interventions (FCI) offer the opportunity to rescue a fetus at risk of intrauterine death, or more ambitiously to alter disease progression. Most of these fetuses require multiple additional postnatal procedures, and it is difficult to disentangle the effect of the fetal procedure from that of the postnatal management sequence. The tr...

Objectives: To analyze the survival, neonatal management, neurodevelopmental outcome and outcome predictors for fetal hydrothorax (FHT) treated with thoracoamniotic shunts. Methods: Retrospective analysis of 132 fetuses undergoing thoracoamniotic shunting at our centre between 1992 and 2014. Results: Mean gestational age at presentation was 25...

The cover image is based on the Original Article * Variability in antenatal prognostication of fetal diaphragmatic hernia across the North American Fetal Therapy Network (NAFTNet) by Nimrah Abbasi** et al., https://doi.org/10.1002/pd.5668.***

Background: Open spina bifida (OSB) is one of the most common congenital central nervous system defects and leads to long-term physical and cognitive disabilities. Open fetal surgery for OSB improves neurological outcomes and reduces the need for ventriculoperitoneal shunting, compared to postnatal surgery, at the expense of increased prematurity....

Background: Open spina bifida (OSB) is one of the most common congenital central nervous system defects and leads to long-term physical and cognitive disabilities. Open fetal surgery for OSB improves neurological outcomes and reduces the need for ventriculoperitoneal shunting, compared to postnatal surgery, but is associated with a significant risk...

Background: Kell and Rhesus (Rh) maternal red blood cell (RBC) alloimmunization are the most common causes of severe fetal haemolytic disease. Widespread use of anti-D immune globulin has dramatically reduced the incidence of Rh(D) alloimmunization, leaving K alloimmunization responsible for a significant proportion of cases of fetal anemia requiri...

Objective: To evaluate variability in antenatal sonographic prognostication of congenital diaphragmatic hernia (CDH) within the North American Fetal Therapy Network (NAFTNet). Methods: NAFTNet centres were invited to complete a questionnaire and participate in videoconference calls, during which participants were observed while measuring lung ar...

Objectives: To assess the natural evolution of the size of the fetal lateral ventricles throughout pregnancy in fetuses with callosal anomalies. Methods: Cases of fetal callosal anomalies were retrospectively classified as isolated or complex based on the presence of other structural or genetic anomalies. Longitudinal ultrasound studies were rev...

Fetal pleural effusions can be associated with significant perinatal morbidity and mortality. When diagnosed antenatally, referral to a tertiary fetal medicine center is recommended for a detailed ultrasound evaluation for additional structural abnormalities or features suggestive of congenital infections or fetal anemia. The effusions should be ch...

In this review article, we discuss the most common fetal tumors, their prenatal management, and outcomes. Overall, the most important outcome predictors are tumor histology, size, vascularity, and location. Very large lesions, lesions causing cardiac failure, and hydrops and lesions obstructing the fetal airway have the poorest outcome, as they may...

Background: The risk factors determining the frequency of intrauterine transfusions (IUTs) for severely affected red blood cell alloimmunized singleton pregnancies are not well known. Objective: To assess factors associated with IUT frequency and adverse pregnancy outcomes in transfused pregnancies. Methods: Retrospective cohort analysis of 24...

Objective: To determine the incidence of chromosome abnormalities, submicroscopic chromosomal microarray (CMA) abnormalities and RASopathy Disorders (RD) pathogenic variants in a cohort of pregnant patients with a nuchal translucency (NT) ≥3.5mm. We propose a clinical protocol for surveillance of this group of patients. Methods: A retrospective...

Microcystic congenital cystic adenomatoid malformations (CCAM), when associated with hydrops, carry a dismal prognosis. Options for treatment are limited and experimental, including antenatal corticosteroids, open fetal surgery, laser ablation and, more recently, sclerotherapy. We describe a case of a large, predominantly microcystic CCAM in a hydr...

Objectives Fetal spina bifida is associated with progressive hydrocephalus, leading to postnatal ventriculoperitoneal shunting. The aim of this study was to document the evolution of the size of the fetal lateral ventricles throughout pregnancy in fetuses with spina bifida and to assess whether fetal surgery had a measurable impact on ventricular s...

Objectives To evaluate the impact of introduction of non-invasive prenatal testing (NIPT) on the uptake of invasive testing in pregnancies complicated by fetal central nervous system (CNS) anomalies. Methods Retrospective review of all singleton pregnancies complicated by fetal CNS anomalies seen at a single tertiary center between 2010 and 2017....

Objective: To evaluate the impact of introduction of noninvasive prenatal testing (NIPT) on the uptake of invasive testing in pregnancies complicated by fetal central nervous system (CNS) anomalies. Methods: Retrospective review of all singleton pregnancies complicated by fetal CNS anomalies seen at a single tertiary center between 2010 and 2017...

Objective: To determine the antenatal sonographic lung area measurement method in left congenital diaphragmatic hernia (CDH) with the highest interrater agreement among North American Fetal Therapy Network (NAFTNet) centers within and outside the fetoscopic tracheal occlusion (FETO) consortium and in comparison with a European "expert" reviewer (E...

Objective: Fetal myelomeningocele (fMMC) surgery improves infant outcomes when compared with postnatal surgery. Surgical selection criteria and the option of pregnancy termination, however, limit the number of cases that are eligible for prenatal surgery. We aimed to quantify what proportion of cases could ultimately benefit from fetal therapy. M...

A healthy 27‐year‐old woman was referred to our hospital at 21 weeks gestation. Fetal echocardiography revealed multiple cardiac rhabdomyomas, with the largest lesion in the left ventricle measuring 10x5mm. This article is protected by copyright. All rights reserved.

A circular shunt (CS) is a life‐threatening condition consisting of massive shunting of systemic arterial blood via the ductus arteriosus to the left ventricle without traversing the lungs. In the prenatal circulation, it mainly occurs in severe Ebstein anomaly (EA) from unrestricted ductal flow and significant pulmonary and tricuspid regurgitation...

Prenatal observed/expected lung–to-head ratio (O/E LHR) by ultrasound correlates with postnatal mortality for congenital diaphragmatic hernia (CDH) patients. The aim of this study is to determine if O/E LHR correlates with pulmonary hypertension (PH) outcomes for CDH patients. Methods A single center retrospective chart review was performed for CD...

We report the first ultrasonographically guided percutaneous balloon atrial septoplasty (BAS), to our knowledge, in a fetus with transposition of the great arteries and an intact ventricular and atrial septum (37 + 2 weeks). After vaginal delivery at 38 weeks, the infant had an elective septostomy (day 1) and an arterial switch procedure (day 7), w...

This chapter provides an overview of the normal atrial septum and the main lesions that are associated with prenatal septal restriction, proposes selection criteria of patients and procedures for possible in utero interventions, and illustrates the fetal and postnatal outcome after intrauterine intervention.

Objectives The detection of fetal anemia by middle cerebral artery peak systolic velocity is less reliable with advancing gestational age (GA) and prior transfusion. We sought to investigate the feasibility and accuracy of a new MRI method for measuring fetal hematocrit (Hct) in vivo in anemic fetuses. Methods We recruited 4 pregnant women suspec...

Percutaneous, ultrasound-guided fetal cardiac intervention (FCI) is increasingly used to alter the prognosis of specific forms of congenital heart disease. Careful patient selection and postnatal management strategy are essential for optimal outcomes. This article discusses the rationale, patient selection criteria, procedural techniques and contem...

Aim: The aim of this study was to investigate the association of observed/expected (O/E) lung-to-head ratio (LHR) with long-term morbidity for isolated fetal congenital diaphragmatic hernia (CDH) patients in a single institution. Methods: We performed a retrospective study of prenatally diagnosed CDH from 18 to 38weeks of gestation (01/2002-04/2...

Objectives: The purpose of this study was to identify the most accurate sonographic models for fetal weight estimation in specific subgroups of small-for-gestational-age (SGA) fetuses. Methods: We conducted a retrospective study of women who delivered an SGA neonate and underwent a sonographic estimation of fetal weight within 7 days of delivery...

What's already known about this topic? Rarely, prenatal fetal inguinoscrotal hernia may be diagnosed during intra-uterine life. To date, few cases have been published in the literature. The pathogenetic mechanism underlying fetal inguinal hernia remains unclear. What does this study add? This is the first case of fetal inguinoscrotal hernia associa...

To evaluate the incidence and consequences of "misdiagnosed" cases of twin-twin transfusion syndrome (TTTS). Chorionicity and referral diagnoses were reviewed in pregnant women with monochorionic twin pregnancies complicated by TTTS treated by fetoscopic laser ablation. "Misdiagnosed" cases, defined as failure to correctly identify chorionicity and...