Fetal imaging: Executive summary of a Joint Eunice Kennedy Shriver National Institute of Child Health and Human Development, Society for Maternal-Fetal Medicine, American Institute of Ultrasound in Medicine, American College of Obstetricians and Gynecologists, American College of Radiology, Society for Pediatric Radiology, and Society of Radiologists in Ultrasound Fetal Imaging Workshop

Decision-making for congenital anomalies diagnosed during pregnancy: a narrative review

PURPOSE

The purpose of this narrative review was to assess the limited literature on fetal anomalies diagnosed in the second trimester of pregnancy and parental decision-making and identify sources of information deemed as facilitators and barriers to medical decisions.

METHODS

This was a literature review of source material and information about fetal anomalies diagnosed in the second trimester of pregnancy, decision-making, decision tools or aids, and sources of information for anomalies. The search string used explored related peer-reviewed publications and systematic reviews between 2007 and 2024. We also reviewed references from publications meeting inclusion criteria. The search was conducted between June 2022 and February 2024. Exclusion criteria included conference abstracts, non-peer reviewed literature, and articles not available in English language. A total of 77 publications were identified by searching multiple databases using a predefined search string. The search encompassed full text articles from 2007 to 2024 and 11 full-text publications were ultimately included in the review. A list of 45 co-occurring keywords was generated from the included texts, with each keyword having a minimum of two co-occurrences.

RESULTS

Key themes identified included (1) the role of the clinician and need for development of professional knowledge and empathy surrounding discussion of fetal anomalies with patients; (2) information gathering, with individuals reporting use of multiple strategies to obtain information; while the majority found information satisfying, they preferred more details on diagnosis, long-term outcomes of the fetus/child and management of the pregnancy or termination process; and (3) decision-making, the path and process of how individuals made decisions about the pregnancy including quality of life, future fertility, and seeking other people's experiences.

CONCLUSION

Many factors contribute to an individual's decision-making after a diagnosis of a fetal anomalies diagnosed in the second trimester of pregnancy, ranging from personal beliefs and goals to shared experiences of others and access to care. Understanding how sources of information may be deemed both as facilitators and barriers to different individuals during the decision-making process is important for healthcare providers in order to understand how to most effectively support patients. There is a dearth of information on training healthcare professionals to provide support to patients facing these decisions.

Incorporation of vasa previa screening into a routine anomaly scan: A single center cohort study

INTRODUCTION

Vasa previa (VP), defined as unprotected fetal vessels traversing the membranes over the cervix, is associated with a high perinatal mortality when undiagnosed prenatally. Conversely, prenatal diagnosis with ultrasound and cesarean delivery before the membranes rupture is associated with excellent outcomes. However, controversy exists regarding screening for VP. In the UK, routine screening for VP is not recommended. The objective of this study was to report the incidence of VP and our experience in the detection of VP with a universal screening protocol at the time of the second-trimester fetal anomaly scan with third-trimester confirmation in an unselected population of pregnancies.

MATERIAL AND METHODS

We performed a single-center historical cohort study of all pregnant women who underwent routine second-trimester anomaly screening scans at West Middlesex University Hospital, London, UK, between 2012 and 2016. Over 5 years, every patient undergoing routine anomaly screening was evaluated for VP using a systematic protocol during their 20-week anomaly scan. Suspected cases of VP were rescanned in the third trimester by specialist sonographers with an interest in VP. The primary outcomes were the incidence and detection of VP.

RESULTS

During the study period, 24 690 anatomy scans were performed. A total of 64 patients were identified as having potential VP at the second-trimester anomaly screening scan, of which 19 were confirmed by the specialist sonographer in the third trimester and at delivery. The screen positive rate was 0.26% (95% confidence interval [CI] 0.20%-0.32%). VP at birth was found in 19/24690 births (1:1299 [95% CI: 1:832-1:2030] births). Universal screening for VP using our protocol had a sensitivity of 100% and a specificity of 99.78% (95% CI: 99.72%-99.84%). The false-positive rate of the second-trimester screen was 0.18% (95% CI: 0.13-0.24). There were no false positives or false negatives at delivery. Of the 19 patients with confirmed VP, 17 had scheduled cesarean deliveries, and two required emergency deliveries due to antepartum hemorrhage. One baby died, giving a perinatal mortality of 5%.

CONCLUSIONS

VP complicates approximately 1:1300 pregnancies. Routine screening for VP yielded a 100% detection rate. We suggest the inclusion of structured VP assessment in standard fetal anomaly screening programs.

Vasa previa in singleton pregnancies: diagnosis and clinical management based on an international expert consensus

BACKGROUND

There are limited data to guide the diagnosis and management of vasa previa. Currently, what is known is largely based on case reports or series and cohort studies.

OBJECTIVE

This study aimed to systematically collect and classify expert opinions and achieve consensus on the diagnosis and clinical management of vasa previa using focus group discussions and a Delphi technique.

STUDY DESIGN

A 4-round focus group discussion and a 3-round Delphi survey of an international panel of experts on vasa previa were conducted. Experts were selected on the basis of their publication record on vasa previa. First, we convened a focus group discussion panel of 20 experts and agreed on which issues were unresolved in the diagnosis and management of vasa previa. A 3-round anonymous electronic survey was then sent to the full expert panel. Survey questions were presented on the diagnosis and management of vasa previa, which the experts were asked to rate on a 5-point Likert scale (from "strongly disagree"=1 to "strongly agree"=5). Consensus was defined as a median score of 5. Following responses to each round, any statements that had median scores of ≤3 were deemed to have had no consensus and were excluded. Statements with a median score of 4 were revised and re-presented to the experts in the next round. Consensus and nonconsensus statements were then aggregated.

RESULTS

A total of 68 international experts were invited to participate in the study, of which 57 participated. Experts were from 13 countries on 5 continents and have contributed to >80% of published cohort studies on vasa previa, as well as national and international society guidelines. Completion rates were 84%, 93%, and 91% for the first, second, and third rounds, respectively, and 71% completed all 3 rounds. The panel reached a consensus on 26 statements regarding the diagnosis and key points of management of vasa previa, including the following: (1) although there is no agreement on the distance between the fetal vessels and the cervical internal os to define vasa previa, the definition should not be limited to a 2-cm distance; (2) all pregnancies should be screened for vasa previa with routine examination for placental cord insertion and a color Doppler sweep of the region over the cervix at the second-trimester anatomy scan; (3) when a low-lying placenta or placenta previa is found in the second trimester, a transvaginal ultrasound with Doppler should be performed at approximately 32 weeks to rule out vasa previa; (4) outpatient management of asymptomatic patients without risk factors for preterm birth is reasonable; (5) asymptomatic patients with vasa previa should be delivered by scheduled cesarean delivery between 35 and 37 weeks of gestation; and (6) there was no agreement on routine hospitalization, avoidance of intercourse, or use of 3-dimensional ultrasound for diagnosis of vasa previa.

CONCLUSION

Through focus group discussion and a Delphi process, an international expert panel reached consensus on the definition, screening, clinical management, and timing of delivery in vasa previa, which could inform the development of new clinical guidelines.

Obstetric blood transfusion in placenta previa patients with prenatal anemia: a retrospective study

BACKGROUND

The appropriate use of obstetric blood transfusion is crucial for patients with placenta previa and prenatal anemia. This retrospective study aims to explore the correlation between prenatal anemia and blood transfusion-related parameters in this population.

METHODS

We retrieved the medical records of consecutive participants who were diagnosed with placenta previa and underwent cesarean section in our hospital. We compared the baseline demographics and clinical characteristics of patients with and without anemia. The correlation between prenatal anemia and obstetric blood transfusion-related parameters was evaluated using multivariate regression analysis.

RESULTS

A total of 749 patients were enrolled, with a mean prenatal hemoglobin level of 10.87 ± 1.37 g/dL. Among them, 54.87% (391/749) were diagnosed with anemia. The rate of obstetric blood transfusion was significantly higher in the anemia group (79.54%) compared to the normal group (44.41%). The median allogeneic red blood cell transfusion volume in the anemia group was 4.00 U (IQR 2.00-6.00), while in the normal group, it was 0.00 U (IQR 0.00-4.00). The prenatal hemoglobin levels had a non-linear relationship with intraoperative allogeneic blood transfusion rate, massive blood transfusion rate, red blood cell transfusion units, and fresh plasma transfusion volume in patients with placenta previa, with a threshold of 12 g/dL.

CONCLUSIONS

Our findings suggest that prenatal anemia is associated with a higher rate of blood transfusion-related parameters in women with placenta previa when the hemoglobin level is < 12 g/dL. These results highlight the importance of promoting prenatal care in placenta previa patients with a high requirement for blood transfusion.

Cesarean scar ectopic pregnancy: nuances in diagnosis and treatment

A cesarean scar ectopic pregnancy (CSEP) occurs when the embryo implants on the scar of a previous cesarean delivery. The number of births delivered by cesarean section has climbed by 50% over the last decade, from a nadir of 20.7% in 1996 to 32.1% in 2021. As a result, the incidence of CSEP has also increased. Because CSEP may cause serious morbidity such as life-threatening hemorrhage, uterine rupture, placental accreta spectrum, hysterectomy, and even mortality, accurate diagnosis and appropriate management of this condition are essential. This review focuses on the etiology, incidence, clinical diagnosis, and management of CSEPs.

Risk Factors and Pregnancy Outcomes of Antepartum Hemorrhage in Women with Placenta Previa

Placenta previa (PP) is one such complication related to several adverse pregnancy outcomes. Adverse outcomes are likely greater if PP coexists with antepartum hemorrhage (APH). This study aims to evaluate the risk factors and pregnancy outcomes of APH in women with PP. This retrospective case-control study included 125 singleton pregnancies with PP who delivered between 2017 and 2019. Women with PP were divided into two groups: PP without APH (n = 59) and PP with APH (n = 66). We investigated the risk factors associated with APH and compared the differences between both groups in placental histopathology lesions due to APH and the resulting maternal and neonatal outcomes. Women with APH had more frequent antepartum uterine contractions (33.3% vs. 10.2%, P = .002) and short cervical length (< 2.5 cm) at admission (53.0% vs. 27.1%, P = .003). The placentas from the APH group had lower weight (442.9 ± 110.1 vs. 488.3 ± 117.7 g, P = .03) in the gross findings, and a higher rate of villous agglutination lesions (42.4% vs. 22.0%, P = .01) in the histopathologic findings. Women with APH in PP had higher rates of composite adverse pregnancy outcomes (83.3% vs. 49.2%, P = .0001). Neonates born to women with APH in PP had worse neonatal outcomes (59.1% vs. 23.9%, P = .0001). Preterm uterine contractions and short cervical length were the most significant risk factors for APH in PP.

Vasa Previa

Vasa previa refers to unprotected fetal vessels running through the membranes over the cervix. Until recently, this condition was associated with an exceedingly high perinatal mortality rate attributable to fetal exsanguination when the membranes ruptured. However, ultrasonography has made it possible to diagnose the condition prenatally, allowing cesarean delivery before labor or rupture of the membranes. Several recent studies have indicated excellent outcomes with prenatally diagnosed vasa previa. However, outcomes continue to be dismal when vasa previa is undiagnosed before labor. Risk factors for vasa previa include second-trimester placenta previa and low-lying placentas, velamentous cord insertion, placentas with accessory lobes, in vitro fertilization, and multifetal gestations. Recognition of individuals who are at risk and screening them will greatly decrease the mortality rate from this condition. Because of the relative rarity of vasa previa, there are no randomized controlled trials to guide management. Therefore, recommendations on the diagnosis and management of vasa previa are based largely on cohort studies and expert opinion. This Clinical Expert Series review addresses the epidemiology, pathophysiology, natural history, diagnosis and management of vasa previa, as well as innovative treatments for the condition.

Hemorrhagic morbidity in nulliparous patients with placenta previa without placenta accrete spectrum disorders

Background

Placental adhesion spectrum (PAS) is a disease in which the trophoblast invades the myometrium, and is a well-known high-risk condition associated with placental previa.

Aim

The morbidity of nulliparous women with placenta previa without PAS disorders is unknown.

Patients and Methods

The data from nulliparous women who underwent cesarean delivery were collected retrospectively. The women were dichotomized into malpresentation (MP) and placenta previa groups. The placenta previa group was categorized into previa (PS) and low-lying (LL) groups. When the placenta covers the internal cervical os, it is called placenta previa, when the placenta is near the cervical os, it is called the low-lying placenta. Their maternal hemorrhagic morbidity and neonatal outcomes were analyzed and adjusted using multivariate analysis based on univariate analysis.

Results

A total of 1269 women were enrolled: 781 women in the MP group and 488 women in the PP-LL group. Regarding packed red blood cell transfusion, PP and LL had adjusted odds ratio (aOR) of 14.7 (95% confidence interval (CI): 6.6 - 32.5), and 11.3 (95% CI: 4.9 - 26) during admission, and 51.2 (95% CI: 22.1 - 122.7) and 10.3 (95% CI: 3.9 - 26.6) during operation, respectively. For intensive care unit admission, PS and LL had aOR of 15.9 (95% CI: 6.5 - 39.1) and 3.5 (95% CI: 1.1 - 10.9), respectively. No women had cesarean hysterectomy, major surgical complications, or maternal death.

Conclusion

Despite placenta previa without PAS disorders, maternal hemorrhagic morbidity was significantly increased. Thus, our results highlight the need for resources for those women with evidence of placenta previa including a low-lying placenta, even if those women do not meet PAS disorder criteria. In addition, placenta previa without PAS disorder was not associated with critical maternal complications.

Fetal Hands: A Comprehensive Review of Prenatal Assessment and Diagnosis Over the Past 40 Years

Fetal skeletal dysplasias involving limbs and hands are rare congenital malformations. Prenatal two-dimensional ultrasound diagnosis of fetal limb defects has a sensitivity of about 30%; however, an increased detection rate may be obtained using three-dimensional (3-D) ultrasound in the rendering mode. 3-D ultrasound may be used as a complementary method providing additional information. Currently, magnetic resonance imaging (MRI), with the emergence of ultrafast imaging techniques and new sequences, allows for better diagnosis of several fetal skeletal dysplasias such as limb reduction defects and neuromuscular disorders. 3-D volumetric images from ultrasound or MRI scan data allow 3-D ultrasound reconstructions of virtual/physical models, and virtual reality can help researchers to improve our understanding of both normal and abnormal fetal limb/hand anatomy. In this article, we review the embryological development of fetal hands and their main anomalies including prenatal diagnostic methods, genetic counseling, the role of orthopedic and plastic surgery reconstruction, and new perspectives in fetal surgery.

Ultrasound in Pregnancy

This article reviews the use of ultrasound in pregnancy pertinent to the emergency physician. The techniques for transabdominal and transvaginal studies are detailed including approaches to gestational dating. Diagnosis of ectopic pregnancy is reviewed focusing on the potential pitfalls: reliance on beta-human chorionic gonadotropin, pseudogestational sac, interstitial pregnancy, and heterotopic pregnancy. Techniques for the identification of placental issues and presenting parts during the second and third trimesters are reviewed. Ultrasound is a safe and effective tool for the experienced emergency physician and is integral to providing high-quality care to pregnant women.

Effects of psychiatric disorders on ultrasound measurements and adverse perinatal outcomes in Chinese pregnant women: A ten-year retrospective cohort study

BACKGROUND

Placental health and serial fetal ultrasound parameters deficits in fetal development in women with psychiatric disorders have yet to be understood. This study aimed to examine the effects of psychiatric disorders on placental health, ultrasound measurements, and adverse perinatal outcomes among Chinese pregnant women.

METHODS

All the pregnant women with psychiatric disorders who delivered at Women's Hospital School of Medicine, Zhejiang University, China, between 2010 and 2020 were included. A total of 992 women (716 in the healthy control group and 276 in the psychiatric disorders group) were recruited. Outcomes include maternal and neonatal birth outcomes. Linear and logistic regression models were used to determine the beta (β) and odds ratios (OR) across 2 models after adjusting for multiple covariates.

RESULTS

For women with psychiatric diagnoses, the mean placental measurements and serial fetal ultrasound parameters, and neonatal birth weight were lower than general pregnant women. After controlling the use of psychotropic medication during pregnancy, women with psychiatric diagnoses showed higher rates of placental implantation abnormalities or placental adhesion (OR = 5.724, 95% CI = [1.805, 15.408]), gestational diabetes mellitus (OR = 3.861, 95% CI = [2.109, 7.068]), anemia in pregnancy (OR = 4.944, 95% CI = [2.306, 10.598]), preterm birth <37 weeks' gestation (OR = 3.200, 95% CI = [1.702, 6.016]), low birth weight (OR = 11.299, 95% CI = [4.068, 31.386]), and neonatal intensive care unit admission (OR = 3.143, 95% CI = [1.656, 5.962]) compared to women in the healthy control group.

CONCLUSION

Pregnant women with psychiatric disorders were more likely to have poor placental outcomes, more ultrasound parameter abnormalities and obstetrical complications, and a higher risk for adverse birth outcomes.

Timing of cesarean delivery in women with uncomplicated placenta previa

OBJECTIVE

The optimal timing of an elective cesarean delivery for uncomplicated placenta previa remains controversial. Although the present guidelines recommend an elective cesarean delivery between 36^0/7 and 37^6/7weeks of gestation, data supporting this recommendation does not differentiate in outcomes between elective and emergent delivery, or between women with and without ante-partum hemorrhage. Recommendations regarding optimal timing of delivery are based on the risks and benefits associated with delivery at a certain gestational week, compared with a reference of 38 weeks. Therefore, the aim of this paper was to assess the maternal and neonatal adverse outcomes associated with elective delivery at different gestational weeks from 36^0/7 to 38^6/7weeks compared with expectant management in women with uncomplicated placenta previa.

METHODS

A retrospective cohort study in a single tertiary medical center of 251 women with a diagnosis of uncomplicated placenta previa, who delivered between 36^0/7 and 38^6/7weeks of gestation, who delivered at our center between Jan 2011 and Dec 2019. Maternal and neonatal outcomes at each gestational week were compared with expectant management.

RESULTS

At 36^0/7-36^6/7weeks, the rate of composite maternal adverse outcome was similar for elective delivery and expectant management (10.5% vs 7.7%, p = .68). Similarly, at 37^0/7-37^6/7 the rate of composite maternal adverse outcome was comparable for elective cesarean delivery and expectant management (7.2% vs 6.4%, p = .54). Maternal bleeding was the main indication of an urgent cesarean delivery, and account for 86% of urgent cesarean delivery at 36^0/7-36^6/7, 76.4% of urgent cesarean delivery at 37^0/7-37^6/7, and for 70.6% of all urgent cesarean delivery at 38^0/7-38^6/7weeks. This group of women who were delivered due to maternal bleeding had a history of maternal bleeding during 2nd and/or 3rd trimester in 75-92.3% of cases. Composite adverse neonatal outcome was similar for elective cesarean delivery at each gestational age compared with expectant management. The risk for lower 5-min APGAR score and hypoglycemia was higher for newborns that were delivered electively a 36th weeks of gestation compared with expectant management.

CONCLUSION

Our study suggests that the optimal time of delivery for women with an uncomplicated placenta previa is between 38^0/7 and 38^6/7weeks of gestation, especially in women without ante-partum bleeding.

Transient Idiopathic Polyhydramnios: Maternal and Perinatal Outcomes: Maternal and Perinatal Outcomes

OBJECTIVES

To compare maternal and perinatal outcomes in pregnancies with transient and persistent idiopathic polyhydramnios to those with normal amniotic fluid volume.

METHODS

This retrospective cohort study included subjects delivering a singleton pregnancy between January 1, 2015, and June 30, 2020, with sonography ≥26 weeks' gestation demonstrating transient or persistent idiopathic polyhydramnios (amniotic fluid index [AFI] ≥24.0 cm) or normal AFI (referent group). The primary maternal outcome was a composite of spontaneous preterm delivery <37 weeks, cesarean delivery for malpresentation, abnormal labor progress, or nonreassuring fetal status, operative vaginal delivery, hemorrhage requiring transfusion, and umbilical cord prolapse. The primary perinatal outcome was a composite of birthweight >4500 g, fetal or neonatal death, 5-minute Apgar score <7, and neonatal intensive care unit admission for >24 hours.

RESULTS

Patients with transient polyhydramnios (n = 259) exhibited maternal outcomes similar to those of the referent group (n = 435) but had significantly increased odds for the primary perinatal outcome (odds ratio [OR] 1.70, 95% confidence interval [CI] 1.15-2.53; P = .008) and for birthweight ≥4500 g (OR 8.70, 95% CI 1.89-40.0; P = .005). Persistent polyhydramnios (n = 176) was significantly associated with both the primary maternal (OR 1.93, 95% CI 1.27-2.95, P = .002) and primary perinatal outcome (OR 2.15, 95% CI 1.40-3.30; P < .001), and individually with cesarean delivery for abnormal labor (OR 3.22, 95% CI 1.55-6.68; P = .002) and birthweight ≥4500 g (OR 8.97, 95% CI 1.84-43.6; P = .007).

CONCLUSIONS

Transient idiopathic polyhydramnios does not impact maternal outcomes but is associated with increased odds of newborn birthweight >4500 g. Persistent polyhydramnios is associated with both adverse maternal and perinatal outcomes.

Trial of Labor Compared With Elective Cesarean Delivery for Low-Lying Placenta

OBJECTIVE

To compare outcomes of women with low-lying placenta by planned mode of delivery and distance from the internal os distance.

METHODS

Six tertiary maternity hospitals in France participated in this retrospective multicenter study of births from 2007-2012. Women with low-lying placenta , defined as an internal os distance of 20 mm or less, who gave birth after 35 weeks of gestation were included and classified in the planned trial-of-labor or elective cesarean delivery groups. The primary endpoint was severe postpartum hemorrhage (PPH) defined as blood loss exceeding 1,000 mL. Secondary outcomes were composite variables of severe maternal and neonatal morbidity. We used multivariable logistic regression and propensity scores to compare outcomes by planned mode of delivery.

RESULTS

Among 128,233 births during the study period, 171 (0.13%) women had low-lying placenta: 70 (40.9%) in the trial-of-labor group and 101 (59.1%) who underwent elective cesarean delivery. The rate of severe PPH was 22.9% (16/70, 95% CI 13.7-34.4) for the trial-of-labor group and 23.0% (23/101, 95% CI 15.2-32.5) for the cesarean delivery group ( P =.9); severe maternal and neonatal morbidity rates were likewise similar (2.9% vs 2.0% [ P =.7] and 12.9% vs 9.9% [ P =.5], respectively). Trial-of-labor was not significantly associated with a higher rate of severe PPH after multivariable logistic regression and propensity score-weighted analysis (adjusted odds ratio [aOR] 1.42, 95% CI 0.62-3.24 [ P =.4]; and aOR 1.34, 95% CI 0.53-3.38 [ P =.5], respectively). The vaginal delivery rate in the trial-of-labor group was 50.0% (19/38) in those with an internal os distance of 11-20 mm and 18.5% (5/27) in those with a distance of 1-10 mm.

CONCLUSION

Our results support a policy of offering a trial of labor to women with low-lying placenta after 35 weeks of gestation and an internal os distance of 11-20 mm. An internal os distance of 1-10 mm reduces the likelihood of vaginal birth considerably, compared with 11-20 mm, but without increasing the incidence of severe PPH or severe maternal morbidity.

The amniotic fluid index and oligohydramnios: a deeper dive into the shallow end

Second- and third-trimester obstetrical ultrasound examinations include an amniotic fluid volume assessment. Professional organizations' clinical guidance recommends using semiquantitative techniques, such as the single deepest vertical pocket or amniotic fluid index, for this purpose. The single deepest vertical pocket is described as the preferred method of assessing amniotic fluid volume based on fewer oligohydramnios diagnoses and labor inductions with no demonstrable difference in pregnancy outcomes compared with the amniotic fluid index. We offer an alternative interpretation of the evidence for this advice, drawn from 6 randomized clinical trials and 2 meta-analyses comparing the single deepest vertical pocket to the amniotic fluid index. Individually and collectively, these reports are underpowered to detect significant differences in maternal and perinatal outcomes by study group. Moreover, randomized clinical trials comparing maternal and perinatal outcomes resulting from a policy of labor induction at or beyond 37 weeks of gestation vs expectant care consistently favor labor induction, the very intervention paradoxically cited as favoring the single deepest vertical pocket vs the amniotic fluid index. We conclude that the amniotic fluid index should be considered a reasonable method for third-trimester amniotic fluid assessment and diagnosing oligohydramnios.

Pregnancy and Delivery Outcomes in Women With Persistent Versus Resolved Low-Lying Placenta in the Late Third Trimester

OBJECTIVES

The safest mode of delivery in low-lying placenta is debatable. Little is known about outcomes in low-lying placenta resolved during the late third trimester. We compare outcomes of women with persistent versus resolved low-lying placenta.

METHODS

A retrospective analysis on a prospective cohort of women with low-lying placenta confirmed at 28-30 weeks sonography (01/2009 to 03/2018). Women were followed up serially every 2 to 3 weeks until delivery to assess the placental edge-to-internal os distance (IOD), and included if scan was performed within 28 days before delivery.

RESULTS

There were 86 women: in 21 the low-lying placenta resolved, whereas in 65 persisted (n = 15 IOD 1-10 mm, n = 50 IOD 11-20 mm). Antepartum bleeding associated with higher rates of urgent cesarean delivery in 1-10 mm (P = .041) but not in 11-20 mm (P = 1.000) and >20 mm (P = .333). Among women with IOD >10 mm allowed to labor, vaginal delivery occurred in 76.7% (11-20 mm) and 94.1% (>20 mm) (P = .155), with no difference according to parity (70% and 80% in multiparas, P = .696; 60% and 72.7% in nulliparas, P = .698). Severe PPH (P = .922) and hemoglobin drop (P = .109) were similar among groups. Women with IOD 11-20 mm and >20 mm and vaginal delivery bled less than women with similarly located placenta and cesarean delivery (P = .009 and P = .048).

CONCLUSIONS

Women with IOD >10 mm have high chances of deliver vaginally with no further increase of their hemorrhagic risk. Success of vaginal delivery is independent of parity and antepartum bleeding. Labor should be managed in an adequate hospital setting.

Guideline No. 402: Diagnosis and Management of Placenta Previa

OBJECTIVES

To summarize the current evidence and to make recommendations for diagnosis and classification of placenta previa and for managing the care of women with this diagnosis.

OPTIONS

To manage in hospital or as an outpatient and to perform a cesarean delivery preterm or at term or to allow a trial of labour when a diagnosis of placenta previa or a low-lying placenta is suspected or confirmed.

OUTCOMES

Prolonged hospitalization, preterm birth, rate of cesarean delivery, maternal morbidity and mortality, and postnatal morbidity and mortality.

INTENDED USERS

Family physicians, obstetricians, midwives, and other maternal care providers.

TARGET POPULATION

Pregnant women with placenta previa or low-lying placenta.

EVIDENCE

Medline, PubMed, Embase, and the Cochrane Library were searched from inception to October 2018. Medical Subject Heading (MeSH) terms and key words related to pregnancy, placenta previa, low-lying placenta, antepartum hemorrhage, short cervical length, preterm labour, and cesarean. This document represents an abstraction of the evidence rather than a methodological review.

VALIDATION METHODS

This guideline has been reviewed by the Maternal-Fetal Medicine and Diagnostic Imaging committees of the Society of Obstetricians and Gynaecologists of Canada (SOGC) and approved by the SOGC Board of Directors.

BENEFITS, HARMS, AND/OR COSTS

Women with placenta previa or low-lying placenta are at increased risk of maternal, fetal and postnatal adverse outcomes that include a potentially incorrect diagnosis and possibly unnecessary hospitalization, restriction of activities, early delivery, or cesarean delivery. Optimization of diagnosis and management protocols has potential to improve maternal, fetal and postnatal outcomes.

SUMMARY STATEMENTS (GRADE RATINGS IN PARENTHESES)

RECOMMENDATIONS (GRADE RATINGS IN PARENTHESES).

Examining ultrasound diagnostic performance improvement with utilization of maternal-fetal medicine tele-interpretation

BACKGROUND

Telemedicine can extend essential health services to under-resourced settings and improve the quality of obstetrical care. Specifically, the evaluation and management of fetal anomalies require perinatal subspecialists, rendering prenatal diagnosis essential, and may benefit from telemedicine platforms to improve access to care.

OBJECTIVE

This study aimed to evaluate the impact of a maternal-fetal medicine telemedicine ultrasound program on the diagnostic accuracy of fetal anomalies when used within practices where ultrasounds are interpreted by general obstetricians or family medicine physicians.

STUDY DESIGN

This was a cross-sectional study of all patients receiving care at 11 private obstetrical practices and imaging centers who had obstetrical ultrasounds performed from January 1, 2020, to July 6, 2020. All ultrasounds were performed by sonographers remotely trained under a standardized protocol and interpreted by maternal-fetal medicine physicians via telemedicine. Ultrasound characteristics and interpretation were extracted from ultrasound reports. Before the introduction of maternal-fetal medicine telemedicine, all ultrasound interpretations were reviewed by general obstetricians and family medicine physicians with reliance predominantly on the sonographer's impression. The primary outcome was potential missed diagnosis of a fetal anomaly, defined as an ultrasound designated as normal by a sonographer but diagnosed with an anomaly by a maternal-fetal medicine physician via telemedicine. This outcome serves as a proxy measure for anomaly diagnoses that would likely be missed without the supervision of a maternal-fetal medicine physician. The characteristics of the potential missed diagnoses were compared by type of scan and fetal organ system in univariable analysis. Moreover, a survey was conducted for sonographers and obstetrical providers to assess their perceptions of ultrasound interpretation via telemedicine.

RESULTS

Overall, 6403 ultrasound examinations were evaluated, 310 of which had a diagnosis of fetal anomaly by a maternal-fetal medicine physician (4.8%). Of the fetal anomalies, 43 were diagnosed on an anatomic survey (13.9%), and 89 were diagnosed as cardiac anomalies (28.7%). The overall rate of the potential missed diagnoses was 34.5% and varied significantly by type of ultrasound (anatomy scans vs other first-, second-, and third-trimester ultrasounds) (P<.01). Moreover, there were significant differences in the rate of the potential missed diagnoses by organ system, with the highest rate for cardiac anomalies (P<.01).

CONCLUSION

Expertise in maternal-fetal medicine telemedicine improves the diagnostic performance of antenatal ultrasound throughout pregnancy. However, there are implications for improving the quality of antenatal care, such as ensuring appropriate referrals and site of delivery, particularly for cardiac anomalies.

Role of prenatal imaging in the diagnosis and management of fetal facio-cervical masses

Congenital facio-cervical masses can be a developmental anomaly of cystic, solid, or vascular origin, and have an inseparable relationship with adverse prognosis. This retrospective cross-sectional study aimed at determining on the prenatal diagnosis of congenital facio-cervical masses, its management and outcome in a large tertiary referral center. We collected information on prenatal clinical data, pregnancy outcomes, survival information, and final diagnosis. Out of 130 cases of facio-cervical masses, a total of 119 cases of lymphatic malformations (LMs), 2 cases of teratoma, 2 cases of thyroglossal duct cyst, 4 cases of hemangioma, 1 case of congenital epulis, and 2 cases of dermoid cyst were reviewed. The accuracy of prenatal ultrasound was 93.85% (122/130). Observations of diameters using prenatal ultrasound revealed that the bigger the initial diameter is, the bigger the relative change during pregnancy. Magnetic resonance imaging (MRI) revealed that 2 cases of masses were associated with airway compression. In conclusion, ultrasound has a high overall diagnostic accuracy of fetal face and neck deformities. Prenatal US can enhance the management of ambulatory monitoring and classification. Furthermore, MRI provided a detailed assessment of fetal congenital malformations, as well as visualization of the trachea, presenting a multi-dimensional anatomical relationship.

Effect of types of placenta previa on maternal and neonatal outcomes: a 10-year retrospective cohort study

PURPOSE

Through this study, we aimed to evaluate the effects of different types of placenta previa (PP) on maternal and neonatal outcomes.

METHODS

This study was conducted in The Third Affiliated Hospital of Guangzhou Medical University and Tongji Hospital between January 2009 and 2019. PP was traditionally classified into four types, namely low-lying placenta, marginal, partial, and complete PP. Previous studies have classified PP into two types, namely low-lying placenta and PP. Based on our clinical experience, we proposed the classification of PP into three types, for the first time, which included low-lying placenta, "marpartial" (marginal and partial) PP, and complete PP. Multivariate logistic regression analysis was performed to determine the effects of different types of PP on maternal and neonatal outcomes.

RESULTS

In total, 4490 singleton pregnancies were complicated with PP. In the four-classification method, compared with women with low-lying placenta, women with complete PP had a risk of placenta accrete spectrum disorders, postpartum hemorrhage (PPH), hemorrhagic shock, severe PPH, blood transfusion, hysterectomy, puerperal infection, preterm labor, NICU admission, and low birth weight. There was no difference in maternal and neonatal outcomes between marginal and partial PP, except for increased chances of preterm labor and low birth weight in partial PP. In the two-classification method, PP was the risk factor for most of the adverse maternal and neonatal outcomes, compared with low-lying placenta.

CONCLUSION

Complete PP and low-lying placenta were associated with the highest and lowest risks of adverse pregnancy outcomes, respectively, whereas clinically similar outcomes were observed between marginal and partial PP. The three-classification of PP may be practical from the clinical perspective.

Chromosomal mosaicism detected by karyotyping and chromosomal microarray analysis in prenatal diagnosis

To investigate the incidence and clinical significance of chromosomal mosaicism (CM) in prenatal diagnosis by G‐banding karyotyping and chromosomal microarray analysis (CMA). This is a single‐centre retrospective study of invasive prenatal diagnosis for CM. From 5758 karyotyping results and 6066 CMA results, 104 foetal cases with CM were selected and analysed further. In total, 50% (52/104) of foetal cases with CM were affected by ultrasound‐detectable phenotypes. Regardless of whether they were singleton or twin pregnancies, isolated structural defects in one system (51.35%, 19/37 in singletons; 86.67%, 13/15 in twins) and a single soft marker (18.92%, 7/37 in singletons; 13.33%, 2/15 in twins) were the most common ultrasound anomalies. Mosaic autosomal trisomy (19.23%, 20/104) was the most frequent type, and its rate was higher in phenotypic foetuses (28.85%, 15/52) than in non‐phenotypic foetuses (9.62%, 5/52). There was no difference in mosaic fractions between phenotypic and non‐phenotypic foetuses based on specimen sources or overall classification. Discordant mosaic results were observed in 16 cases (15.38%, 16/104) from different specimens or different testing methods. Genetic counselling and clinical management regarding CM in prenatal diagnosis remain challenging due to the variable phenotypes and unclear significance. Greater caution should be used in prenatal counselling, and more comprehensive assays involving serial ultrasound examinations, different specimens or testing methods verifications and follow‐up should be applied.

[Genital abnormalities: Contextualization of a neglected area in prenatal diagnosis]

OBJECTIVE

To reflect on how the area of genital abnormalities has fallen behind in prenatal diagnosis.

METHODS

Based on the thesis that prenatal diagnosis of genital abnormalities has scarcely developed, a comparison with other areas of prenatal diagnosis and with its postnatal counterpart is presented; different explanations for this situation are examined; and a reflection is presented on ways to expand this field of knowledge.

CONCLUSIONS

Compared to other disciplines, prenatal diagnosis of genital abnormalities finds itself lagging behind in terms of diagnostic tools, management protocols and scientific literature. Potential causes include a perception of low prevalence and limited importance, or exploration challenges. Integration of current knowledge, together with the acquisition of the appropriate tools and translation to clinical medicine, would be a way to make this discipline stronger.

Should chromosomal microarray be offered to fetuses with ultrasonographic soft markers in second trimester: A prospective cohort study and meta-analysis

OBJECTIVE

To evaluate whether chromosomal microarray (CMA) should be offered to fetuses with ultrasonographic soft markers (USMs) in the second trimester.

METHODS

A prospective cohort study and meta-analysis were conducted. In the prospective cohort study, 564 fetuses with USMs were enrolled. In the meta-analysis, eligible articles describing copy number variations in fetuses with USMs were included.

RESULTS

In the prospective cohort study, the diagnostic yields of CMA over non-invasive prenatal testing (NIPT) and karyotyping were significantly higher in fetuses with mild ventriculomegaly (MVM) than those in local control cohorts with normal ultrasound. However, the yields of CMA over NIPT and karyotyping in fetuses with other USMs were similar to controls. About ten studies, involving 405 fetuses with MVM and 1412 fetuses with other USMs, were included in the meta-analysis. The pooled diagnostic yields of CMA over NIPT and karyotyping in fetuses with MVM were 4.9% and 3.2%, respectively. In fetuses with other USMs, the yields of CMA over NIPT and karyotyping were 1.2% and 0.4%, respectively.

CONCLUSION

It is reasonable to offer CMA as a first-tier test to fetuses with MVM. However, for fetuses with other USMs, the considerations to perform CMA should not differ from pregnancies with normal ultrasound.

Isolated echogenic intracardiac foci and the role of cell-free fetal DNA: A cost-effectiveness analysis

OBJECTIVES

Cell-free fetal DNA (cfDNA) has been increasingly incorporated into prenatal aneuploidy screening paradigms given its relatively high sensitivity for Down syndrome (DS). This is often the case when fetal ultrasonographic soft markers are present, such as the relatively common echogenic intracardiac focus (EIF). We sought to evaluate the cost-effectiveness of a screening strategy that included cfDNA screening when an isolated EIF is identified in a low-risk population with prior aneuploidy screening.

METHODS

A decision-analytic model was constructed using TreeAge software with probabilities derived from the literature. Our model compared cfDNA screening following isolated EIF detection in women less than 35 years with prior reassuring first trimester screen compared to a strategy of no further aneuploidy screening. Strategies were compared to generate an incremental cost-effectiveness ratio with a threshold of $100 000/quality-adjusted life year (QALY) and applied to a theoretical cohort.

RESULTS

The cfDNA strategy resulted in 21 fewer DS births and 52 additional QALYs, however, increased costs by $51.3 million. This yielded an incremental cost-effectiveness ratio of $986 503; therefore, it was not a cost-effective strategy.

CONCLUSION

In a low-risk population with prior reassuring aneuploidy screening, it is not cost effective to offer cfDNA after identification of an isolated EIF.

Prenatal diagnosis of fetal skeletal dysplasias in a tertiary Hospital in Spain

OBJECTIVE

To assess the diagnostic accuracy of prenatal ultrasound for detecting fetal skeletal dysplasias and to describe its role in orienting genetic studies.

STUDY DESIGN

Observational study of pregnant women surveyed in our hospital, between 2011 and 2018, with fetal long bones below the 3rd centile (shortened long bones), either as an isolated finding or associated to other skeletal anomalies. We used a systematic protocol for the ultrasound evaluation and selection of those fetuses suspected of having a skeletal dysplasia. We report the demographics of these patients along with the sonographic follow-up of their fetuses, the genetic results and the outcome of the pregnancies and the newborn in the entire group and also compare data between the two sub-groups (isolated shortened long bones vs shortened long bones associated to other anomalies).

RESULTS

A total of 81 pregnancies with a suspected fetal skeletal dysplasia were included, with a complete follow-up available in 75 cases, 22 with isolated shortened long bones and 53 cases that presented shortened long bones with other skeletal anomalies. In the shortened long bones sub-group, a total of five (23 %) were born healthy neonates, 10 (45 %) were small for gestational age or intrauterine growth restricted (one of them of genetic origin) and seven (32 %) had a skeletal dysplasia (6 of them with genetic diagnosis). Whilst among the 53 cases that presented with shortened long bones + other skeletal anomalies, three (6%) were healthy neonates, five (9%) were small for gestational age/intrauterine growth restricted (two of genetic origin) and 45 (85 %) had a skeletal dysplasia (19 genetically confirmed and 26 with a clinical diagnosis). These differences in frequencies between the two sub-groups were determined to be statistically significant (χ²: p = 0.02).

CONCLUSION

Around one third of fetuses with isolated shortened long bones will have a skeletal dysplasia. If abnormal skeletal ultrasound findings are associated with shortened long bones, the risk for skeletal dysplasia is significantly increased (85 %). Prenatal systematic approach in a multidisciplinary unit is useful in the orientation of genetic studies.

Challenges in preterm birth research: Ghanaian perspective

Preterm birth is highly prevalent in Ghana. It is a major public health concern because of the high burden as well as the associated immediate and long-term consequences including increased healthcare cost. Studies conducted in high-income countries may not be sufficiently generalizable in our context. Locally generated evidence-based interventions will be indispensable in improving the clinical management and prevention of preterm birth in the country. However, there are limited published literature on preterm birth and prematurity in the country. This review seeks to discuss the major challenges associated with preterm birth research in Ghana and proposes evidence-based strategies to improve biomedical and epidemiological research on preterm birth and prematurity. The limited high quality preterm birth research is partly attributable to a variety of challenges related to accurate gestational age estimation, research training, capacity and support including funding, efficient ethics committees, local and international collaboration as well as effective health management information systems. Other related challenges include unavailability of reliable internet connectivity, poor compensation for researchers and lack of conductive research environment. There is the need to expedite advocacy on implementation of practical interventions and strategies aimed at increasing high quality research in the area of preterm birth and prematurity in the country. A paradigm shift in preterm birth research with appropriate integration of concerted multidisciplinary research groups should be constituted to put basic science research to clinical practice as well as the prevention of preterm birth in the country.

Intrauterine versus post-mortem magnetic resonance in second trimester termination of pregnancy for central nervous system abnormalities

OBJECTIVE

To evaluate if limiting factors of intrauterine magnetic resonance imaging (iuMRI) performed in the early second trimester of pregnancy (19-23 weeks) affect its accuracy in comparison to post-mortem MRI (pmMRI) in fetuses that underwent termination of pregnancy (TOP) for central nervous system (CNS) defects.

STUDY DESIGN

This is a secondary analysis of a 10 years prospective observational study. Cases of TOP < 23 weeks for CNS malformation that had undergone neurosonography (NSG), iuMRI, pmMRI and autopsy were included. The agreement between iuMRI and pmMRI was calculated. The autopsy represented the gold-standard.

RESULTS

Overall, 143 TOPs for fetal congenital anomaly underwent the post-mortem diagnostic protocol. Of these, 31 cases underwent iuMRI and pmMRI for CNS abnormality. Three cases were excluded due to brain autolysis at autopsy. Corpus callosum defects were the most represented (16/28; 57 %). In only one case of posterior fossa defect, pmMRI identified the presence of vermian hypoplasia not diagnosed at iuMRI. In 2 cases (7%), iuMRI added clinically relevant additional findings to NSG, that were posteriorly confirmed by pmMRI.

CONCLUSIONS

The study shows that, at 19-23 weeks and for CNS defects, limiting factors that might influence the performance of iuMRI have little influence on iuMRI accuracy. This finding is particularly important for professionals who work in countries with legal bound for TOP in the early second trimester.

Effect of previous placenta previa on outcome of next pregnancy: a 10-year retrospective cohort study

Background

To determine the effects of previous placenta previa on the maternal and neonatal outcomes of the next pregnancy.

Methods

This 10-year retrospective cohort study was conducted in the Department of Obstetrics and Gynecology, Third Affiliated Hospital of Guangzhou Medical University, between January 2009 and 2018. We retrospectively analyzed the effects of a previous singleton pregnancy in women with and without placenta previa on the outcomes of the subsequent pregnancy. To control for confounders, we used multiple logistic regression models.

Results

A total of 57,251 women with singleton pregnancies gave birth during the 10-year study period. Among them, 6070 women had two consecutive births. For the first pregnancy, 1603 women delivered by cesarean delivery and 4467 by vaginal delivery. Among women with a history of cesarean delivery, placenta previa was an independent risk factor for hemorrhage (adjusted odds ratio [aOR]: 2.25, 95% confidence interval [CI]: 1.1–4.62), placenta accreta spectrum (PAS) disorders (aOR: 4.11, 95% CI: 1.68–10.06), and placenta previa (aOR: 6.24, 95% CI: 2.85–13.67) during the subsequent pregnancy. Puerperal infection, blood transfusion, and perinatal outcomes did not significantly differ between women with a history of placenta previa and women without this history. Among women with a history of vaginal delivery, placenta previa increased the risk of PAS disorders (aOR: 5.71, 95% CI: 1.81–18.03) and placenta previa (aOR: 4.14, 95% CI: 1.07–16.04) during the subsequent pregnancy. There was no significant difference between the two groups in terms of hemorrhage, blood transfusion, puerperal infection, and perinatal outcomes.

Conclusions

Women with a history of placenta previa are at risk for adverse outcomes such as postpartum hemorrhage, PAS disorders, and placenta previa in the subsequent pregnancy.

Placental magnetic resonance imaging Part I: the normal placenta

Mounting evidence suggests that the placenta is involved in nearly all abnormalities of pregnancy and fetal development. Traditional imaging evaluation of the placenta by ultrasound has more recently been complemented by MRI for complex cases requiring additional information, such as in the diagnosis of the placenta accreta spectrum (placenta accreta, increta and percreta). MRI can often help delineate the safest approach to delivery and adds diagnostic certainty to enable prognostication and to avoid potentially lethal complications. Increasingly, prenatal MRI has become the purview of the pediatric imager and is becoming the standard of care for select gestational indications. However, placental MRI might be unfamiliar to the radiologist. Thus, we provide a simple and systematic approach to evaluating the placenta by MRI, to enable delivery planning and family counseling.

Neonatal and Maternal Complications of Placenta Praevia and Its Risk Factors in Tikur Anbessa Specialized and Gandhi Memorial Hospitals: Unmatched Case-Control Study

Background

Placenta praevia is a disorder that happens during pregnancy when the placenta is abnormally placed in the lower uterine segment, which at times covers the cervix. The incidence of placenta praevia is 3-5 per 1000 pregnancies worldwide and is still rising because of increasing caesarean section rates.

Objective

To assess and identify the risk factors and maternal and neonatal complications associated with placenta praevia. Method and Materials. Target populations for this study were all women diagnosed with placenta praevia transvaginally or transabdominally either during the second and third trimesters of pregnancy or intraoperatively in Tikur Anbessa Specialized and Gandhi Memorial Hospitals. The study design was unmatched case-control study. Data was carefully extracted from medical records, reviewed, and analyzed. Unconditional logistic regression analysis was performed using adjusted odds ratios (AOR) with 95% confidence intervals.

Results

Pregnancies complicated by placenta praevia were 303. Six neonatal deaths were recorded in this study. The magnitude of placenta praevia observed was 0.7%. Advanced maternal age (≥35) (AOR 6.3; 95% CI: 3.20, 12.51), multiparity (AOR 2.2; 95% CI: 1.46, 3.46), and previous history of caesarean section (AOR 2.7; 95% CI: 1.64, 4.58) had an increased odds of placenta praevia. Postpartum anemia (AOR 14.6; 95% CI: 6.48, 32.87) and blood transfusion 1-3 units (AOR 2.7; 95% CI: 1.10, 6.53) were major maternal complications associated with placenta praevia. Neonates born to women with placenta praevia were at increased risk of respiratory syndrome (AOR 4; 95% CI: 1.24, 13.85), IUGR (AOR 6.3; 95% CI: 1.79, 22.38), and preterm birth (AOR 8; 95% CI: 4.91, 12.90).

Conclusion

Advanced maternal age, multiparity, and previous histories of caesarean section were significantly associated risk factors of placenta praevia. Adverse maternal outcomes associated with placenta praevia were postpartum anemia and the need for blood transfusion. Neonates born from placenta praevia women were also at risk of being born preterm, intrauterine growth restriction, and respiratory distress syndrome.

Cost-Effectiveness of Screening Ultrasound after a First, Febrile Urinary Tract Infection in Children Age 2-24 Months

OBJECTIVE

To estimate the cost-effectiveness of routine, screening renal bladder ultrasound (RBUS) for children age 2-24 months after a first febrile urinary tract infection (UTI), as recommended by the American Academy of Pediatrics.

STUDY DESIGN

We developed a decision analytic model that simulates a population of children after a first febrile UTI. The model incorporates the diagnostic utility of RBUS to detect vesicoureteral reflux and genitourinary anomalies. We adopted a health-system perspective, 5-year horizon, and included 1-way and 2-way sensitivity analyses. Costs were inflated to 2018 US dollars, and our model incorporated a 3% discounting rate. We compared routine RBUS after first, febrile UTI compared with routine RBUS after second UTI (ie, control arm). Our main outcomes were recurrent UTI rate and incremental cost per quality-adjusted life-year (QALY).

RESULTS

Among children 2-24 months after a first febrile UTI, RBUS had an overall accuracy (true positives + true negatives) of 64.4%. The recurrent UTI rate in the intervention arm was 19.9% compared with 21.0% in the control arm. Thus, 91 patients would need to be screened with RBUS to prevent 1 recurrent UTI. RBUS increases QALYs by +0.0002 per patient screened, corresponding to an incremental cost-effectiveness ratio of $803 000/QALY gained. In the RBUS arm, 20.6% of children would receive unnecessary voiding cystourethrograms compared with 12.2% of children in the control group.

CONCLUSIONS

Screening RBUS after a first, febrile UTI in children age 2-24 months does not meet cost-effectiveness guidelines. Our findings support deferred screening until a second UTI.

Frequency of spontaneous resolution of vasa previa with advancing gestational age

BACKGROUND

Vasa previa is a serious obstetric complication that can result in fetal hemorrhage and death on spontaneous labor. Suggested management for vasa previa is elective hospitalization and cesarean delivery before spontaneous labor. There is little reported evidence of the rate of vasa previa resolution over the course of gestation. Identification of the resolution rate and of factors predictive of resolution potentially could improve clinical management and patient counseling.

OBJECTIVE

The purpose of this study was to identify the resolution rate of vasa previa across gestation and to determine clinical and sonographic factors that are associated with vasa previa resolution.

STUDY DESIGN

We conducted a retrospective cohort study of all women who were diagnosed with vasa previa in a single ultrasound unit between 2005 and 2018. Vasa previa was defined as a fetal vessel within 2 cm of the internal cervical os on transvaginal sonography. The primary outcome was vasa previa resolution, defined as migration of the vasa previa to >2 cm away from the internal os.

RESULTS

One hundred women with vasa previa that had been diagnosed at a mean gestational age of 22.8±4.9 weeks were included. Thirty-nine women (39.0%; 95% confidence interval, 30-49%) had resolution of vasa previa at a mean gestational age of 28.6-4.7 weeks. Factors that were associated with vasa previa resolution were an earlier gestational age at diagnosis (adjusted odds ratio, 6.10; 95% confidence interval,1.92-19.40), vasa previa did not cover the internal os at diagnosis (adjusted odds ratio, 8.29; 95% confidence interval, 2.79-24.62), and vasa previa was not the result of a resolved placenta previa (adjusted odds ratio, 2.85; 95% confidence interval, 1.01--8.03). One woman with a dichorionic twin pregnancy and vasa previa resolution (at 31 weeks gestation; fetal vessels located 2.8 cm from the internal os) presented at 33 weeks with massive bleeding and fetal death of twin A. It was unclear whether the death was related to vasa previa or placental abruption.

CONCLUSION

Thirty-nine percent of vasa previas in our population resolved over the course of pregnancy. Earlier gestational age at diagnosis, vasa previa not covering the internal os, and not having a resolved placenta previa all are associated independently with an increased likelihood of vasa previa resolution. Women with vasa previa should be observed serially to assess for vasa previa resolution, because many will resolve in the third trimester.

Uterine arteries prophylactic occlusion balloon placement in pregnancies with placenta praevia

INTRODUCTION

To evaluate the feasibility of uterine arteries prophylactic occlusion balloon placement (POBP) to reduce hemorrhagic complications associated with placenta praevia.

MATERIAL AND METHODS

A retrospective analysis was carried out from January 2014 to November 2018. Only women with a diagnosis of placenta praevia and gestational age at delivery between 33 and 40 weeks were included. All women were diagnosed using transvaginal ultrasound scan (TVS) and confirmed with magnetic resonance imaging (MRI). All women underwent uterine arteries POBP before caesarean delivery (CD). All patients underwent clinical and instrumental follow-up with semestral outpatient TVS for 2 years after the surgery.

RESULTS

Forty-eight pregnant women were recruited and analyzed. 32/48 patients (66%) had positive anamnesis for previous CDs. Mean blood loss was 510 ± 222 mL. 15/48 patients (31.6%) were supported with RBC concentrate transfusion. In 10 (20.8%) cases, an intrauterine haemostatic balloon (Bakri-Balloon, Cook Medical, Spencer, USA) was used to control the intra-operative hemorrhage. Hysterectomy was performed in eight cases (16.6%). No cases of hemodynamic instability or urinary complications were reported. No postoperative complications occurred. During follow-up, no long-term complications were observed and nine patients had a successful pregnancy.

CONCLUSIONS

Uterine arteries POPB is a promising technique that may be adopted in women with placenta praevia to prevent hemorrhagic complications.

Noninvasive assessment of fetal central nervous system insult: Potential application to prenatal diagnosis

OBJECTIVE

We have developed novel methods for isolating fetal central nervous system (CNS)-derived extracellular vesicles (FCEs) from maternal plasma as a non-invasive platform for testing aspects of fetal neurodevelopment in early pregnancy. We investigate the hypothesis that levels of defined sets of functional proteins in FCEs can be used to detect abnormalities in fetal neuronal and glial proliferation, differentiation, and survival.

METHOD

Maternal plasma was obtained between 10 and 19 weeks from women with current heavy EtOH exposure and matched controls. FCE levels of synaptophysin, synaptotagmin, synaptopodin, and neurogranin were quantified normalized to the exosome marker CD81. Quantitative RT-PCR was performed with specific primers for miR-9.

RESULTS

FCE cargo protein levels of synaptophysin, synaptotagmin, synaptopodin, and neurogranin were all significantly reduced in pregnancies exposed to current heavy EtOH use (P < .001 for all). Both synaptophysin and neurogranin appeared to be particularly discriminatory with no overlap between exposed and control subjects. Up to tenfold inhibition (90%) in MicroRNA-9 was observed in FCEs from EtOH exposed fetuses compared with controls.

CONCLUSION

Our results suggest that FCEs purified from maternal plasma may be a powerful tool to assess abnormal proliferation and differentiation of CNS stem cells as early as the late first trimester. What's already known about this topic? Exosomes/extracellular vesicles (ECVs) are emerging as exciting novel biomarkers in neurologic disease (Alzheimers) What does this study add? Evidence that Fetal CNS ECVs can be isolated from maternal blood The origin of the ECVs appears to be the fetal brain and not the placenta Findings with ECVs correlates with fetal exposure to alcohol. Potential for first trimester prenatal diagnosis of fetal neurologic disease.

How to obtain diagnostic planes of the fetal central nervous system using three-dimensional ultrasound and a context-preserving rendering technology

The antenatal evaluation of the fetal central nervous system (CNS) is among the most difficult tasks of prenatal ultrasound (US), requiring technical skills in relation to ultrasound and image acquisition as well as knowledge of CNS anatomy and how this changes with gestation. According to the International Guidelines for fetal neurosonology, the basic assessment of fetal CNS is most frequently performed on the axial planes, whereas the coronal and sagittal planes are required for the multiplanar evaluation of the CNS within the context of fetal neurosonology. It can be even more technically challenging to obtain "nonaxial" views with 2-dimensional (2D) US. The modality of 3-dimensional (3D) US has been suggested as a panacea to overcome the technical difficulties of achieving nonaxial views. The lack of familiarity of most sonologists with the use of 3D US and its related processing techniques may preclude its use even where it could play an important role in complementing antenatal 2D US assessment. Furthermore, once a 3D volume has been acquired, proprietary software allows it to be processed in different ways, leading to multiple ways of displaying and analyzing the same anatomical imaging or plane. These are difficult to learn and time consuming in the absence of specific training. In this article, we describe the key steps for volume acquisition of a 3D US volume, manipulation, and processing with reference to images of the fetal CNS, using a newly developed context-preserving rendering technique.

Magnetic resonance imaging of the placenta and gravid uterus: a pictorial essay

The placenta is commonly overlooked on magnetic resonance imaging of the pregnant patient, which is frequently performed for alternative reasons such as to characterize fetal or uterine anomalies or to investigate the etiology of acute pelvic pain in pregnancy. Placental disorders have potential for significant maternal and fetal morbidity and peripartum complications if not recognized and treated in a timely manner. The radiologist must be familiar with normal placental variants and the spectrum of benign to life-threatening conditions affecting the placenta so that the Obstetrician can be promptly notified and patient management altered, if necessary. In this pictorial essay, we will describe our MR protocol for placental imaging, provide an image-rich review of the normal placenta, placental variants, and a variety of pathological conditions affecting the placenta and gravid uterus.

A survey of pediatric diagnostic radiologists in North America: current practices in fetal magnetic resonance imaging

BACKGROUND

Fetal magnetic resonance imaging (MRI) is an imaging examination in evolution. Rapid developments over recent decades have led to better image quality, an increased number of examinations and greater impact on patient care.

OBJECTIVE

To gather data regarding current practices among established programs in North America and provide information to radiologists interested in implementing or growing a fetal MRI service.

MATERIALS AND METHODS

An electronic survey containing 15 questions relevant to the use of fetal MRI was submitted to pediatric radiologists and neuroradiologists. Items regarded scheduling and reporting logistics, magnet strength, patient positioning and patient preparation. Answers and comments were collected, and descriptive statistics were summarized.

RESULTS

One hundred and six survey responses were evaluated. Of the survey responses, 62/106 (58.5%) allow fetal MR scheduling any time during the day and 72/105 (68.6%) exclusively use 1.5-T strength platforms for fetal MRI, while only 7/105 (6.7%) use exclusively 3 T. Patient positioning is variable: supine, 40/106 (37.8%); left lateral decubitus, 22/106 (20.8%), and, patient's choice, 43/106 (40.6%). Of the centers responding, 51/104 (49.0%) require no particular fasting instructions, while 20/104 (19.2%) request the patient avoid caffeine before the scanning.

CONCLUSION

Logistical trends in performing fetal MRI may supplement the American College of Radiology's published technical standards and offer guidance to radiologists new to the field.