Placental T2* and BOLD effect in response to hyperoxia in normal and growth-restricted pregnancies: multicenter cohort study.

OBJECTIVES: Blood-oxygen-level-dependent (BOLD) magnetic resonance imaging (MRI) facilitates the non-invasive in-vivo evaluation of placental oxygenation. The aims of this study were to identify and quantify a relative BOLD effect in response to hyperoxia in the human placenta and to compare it between pregnancies with and those without fetal growth restriction (FGR). METHODS: This was a prospective multicenter study (NCT02238301) of 19 pregnancies with FGR (estimated fetal weight (EFW) on ultrasound < 5th centile) and 75 non-FGR pregnancies (controls) recruited at two centers in Paris, France. Using a 1.5-Tesla MRI system, the same multi-echo gradient-recalled echo (GRE) sequences were performed at both centers to obtain placental T2* values at baseline and in hyperoxic conditions. The relative BOLD effect was calculated according to the equation 100 × (hyperoxic T2* - baseline T2*)/baseline T2*. Baseline T2* values and relative BOLD effect were compared according to EFW (FGR vs non-FGR), presence/absence of Doppler anomalies and birth weight (small-for-gestational age (SGA) vs non-SGA). RESULTS: We observed a relative BOLD effect in response to hyperoxia in the human placenta (median, 33.8% (interquartile range (IQR), 22.5-48.0%)). The relative BOLD effect did not differ significantly between pregnancies with and those without FGR (median, 34.4% (IQR, 24.1-48.5%) vs 33.7% (22.7-47.4%); P = 0.95). Baseline T2* Z-score adjusted for gestational age at MRI was significantly lower in FGR pregnancies compared with non-FGR pregnancies (median, -1.27 (IQR, -4.87 to -0.10) vs 0.33 (IQR, -0.81 to 1.02); P = 0.001). Baseline T2* Z-score was also significantly lower in those pregnancies that subsequently delivered a SGA neonate (n = 23) compared with those that delivered a non-SGA neonate (n = 62) (median, -0.75 (IQR, -3.48 to 0.29) vs 0.35 (IQR, -0.79 to 1.05); P = 0.01). CONCLUSIONS: Our study confirms a BOLD effect in the human placenta and that baseline T2* values are significantly lower in pregnancies with FGR. Further studies are needed to evaluate whether such parameters may detect placental insufficiency before it has a clinical impact on fetal growth. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

[Impact of sonography simulation in the training of midwifery students]. / Impact de l'intégration de la simulation en échographie obstétricale dans le cursus des étudiants sages-femmes.

OBJECTIVE: During their studies, French midwives need to acquire basic ultrasound skills to measure the amniotic fluid index, fetal biometry and identify fetal lie and placental positions. They have a clinical ultrasound training during their curriculum to acquire these skills. Assess the contribution that a training on an obstetrical ultrasound simulator (OUS) could make to the competence of midwives and to evaluate the best time to integrate it into their curriculum. METHODS: Forty students in their 4th and final year in midwifery were randomized into 2 groups. Group A learned with the traditional academic course, with a clinical ultrasound training which was followed by an evaluation on an OUS (E1A). Group B was evaluated on a simulator before the clinical ultrasound training (E1B). After these initial assessments, both groups were provided with learning and training sessions on OUS, and re-evaluated in the same exercise (E2A and E2B). Group B then completed its clinical ultrasound training and was evaluated one month later on the simulator (E3B). The evaluation consisted of scoring the biometry images according to previously published quality criteria, and of assessing their competence based on a published objective and structured assessment score of ultrasound skills (OSAUS). RESULTS: Evaluation 1 found comparable OSAUS scores (2.375/5 vs. 2.24/5 P=0.52) between the two groups (E1A vs. E1B) but a significantly higher image quality score for Group A (P=0.02). In Evaluation 2, an improvement was noted for both groups with comparable OSAUS averages between the two groups (P=0.76). After the clinical training of Group B, their OSAUS score (E3B) was significantly better than that of Group A (E1A) after their clinical training (3.45/5 vs. 2.375/5 [P=0.00017]). The same was true for the quality of their images (12.67/16 vs. 9.95/16 [P=0.003]). CONCLUSION: Ultrasound simulation-based training, as an adjunct to ultrasound clinical training, significantly improves obstetrical ultrasound skills. The best time to train on simulators seems to be prior to clinical training on real patients.

Fetal brain imaging following laser surgery in twin-to-twin surgery.

OBJECTIVE: To describe the incidence and nature of prenatal brain damage following fetoscopic laser selective coagulation (FLSC) of placental vessels for twin-to-twin transfusion syndrome (TTTS). DESIGN: Retrospective observational study. SETTING: Single center cohort. POPULATION: All consecutive cases referred for TTTS treated by FLSC between 2003 and 2015. METHODS: After the FLSC, patients were followed weekly by ultrasound. Fetal magnetic resonance imaging (MRI) scans were systematically planned at 30-32 weeks of gestation. MAIN OUTCOME MEASURES: Brain damage diagnosed prenatally by ultrasound or MRI. RESULTS: In total, 1023 cases were reviewed. Brain damage was diagnosed prenatally in 22/1023 (2.1%) cases. Diagnosis was performed by ultrasound prior to MRI in 18 (82%) cases. All lesions were within the spectrum of ischaemic haemorrhagic lesions. Postoperative twin anaemia polycythaemia sequence and recurrence of TTTS were significantly associated with brain damage. CONCLUSION: The incidence of prenatal brain damage is low following FSLC, and is strongly associated with incomplete surgery. TWEETABLE ABSTRACT: Following FSLC for TTTS, prenatal brain damage occurs in 2% of cases and is associated with incomplete surgery.

Vein of Galen aneurysmal malformation (VGAM) in the fetus: retrospective analysis of perinatal prognostic indicators in a two-center series of 49 cases.

OBJECTIVE: Vein of Galen aneurysmal malformation (VGAM) is a rare fetal anomaly, the neurological outcome of which can be good with appropriate perinatal management. However, most fetal series are too small to allow reliable statistical assessment of potential prognostic indicators. Our aim was to assess, in a two-center series of 49 cases, the prognostic value of several prenatal variables, in order to identify possible prenatal indicators of poor outcome, in terms of mortality and cerebral disability. METHODS: This was a retrospective study involving 49 cases of VGAM diagnosed prenatally and managed at two centers over a 17-year period (1999-2015). All cases had undergone detailed prenatal cerebral and cardiac assessment by grayscale ultrasound, color and pulsed-wave Doppler and magnetic resonance imaging (MRI). Ultrasound and MRI examination reports and images were reviewed and outcome information was obtained from medical reports. Volume of the VGAM (on ultrasound and MRI) was calculated and development of straight-sinus dilatation, ventriculomegaly and other major brain abnormalities was noted. Cardiothoracic ratio, tricuspid regurgitation and reversed blood flow across the aortic isthmus were evaluated on fetal echocardiography. Major brain lesions were considered by definition to be associated with poor outcome in all cases. Pregnancy and fetoneonatal outcome were known in all cases. Fetoneonatal outcome and brain damage were considered as dependent variables in the statistical evaluation. Poor outcome was defined as death, late termination of pregnancy due to association with related severe brain anomalies or severe neurological impairment. RESULTS: At a mean follow-up time of 20 (range, 0-72) months, 36.7% of the whole series and 52.9% of the cases which did not undergo late termination were alive and free of adverse sequelae. Five (10.2%) cases showed progression of the lesion between diagnosis and delivery. On univariate analysis, dilatation of the straight sinus, VGAM volume ≥ 20 000 mm3 and tricuspid regurgitation were all significantly related to poor outcome. However, on logistic regression analysis, the only variables associated significantly with poor outcome were tricuspid regurgitation and, to a lesser extent, VGAM volume ≥ 20 000 mm3 . The former was also the only variable associated with brain damage. CONCLUSIONS: Major brain lesions, tricuspid regurgitation and, to a lesser extent, VGAM volume ≥ 20 000 mm3 are the only prenatal variables associated with poor outcome in fetal VGAM. Prenatal multidisciplinary counseling should be based on these variables. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

[Outcome of triplet pregnancies managed for twin-to-twin transfusion syndrome: A single center experience]. / Issues des grossesses triples compliquées d'un syndrome transfuseur-transfusé : expérience d'un centre.

OBJECTIVES: Study the outcomes of triplet pregnancies (GGG) complicated with twin-to-twin transfusion syndrome (TTTS) treated with laser fetoscopy. METHODS: Retrospective study of interventions, outcomes and perinatal follow-up of GGG treated for TTS. RESULTS: Between 2002 and 2013, 25 GGG complicated by TTTS were seen in our center, 20 dichorionic and 5 monochorionic. The mean gestational age (GA) at diagnosis of TTTS was 19.7 GW (±2.4) with 2, 4, 16 and 1 pregnancies at Quintero's stage I, II, III and V, respectively. They had a fetoscopy at an average GA of 19 GW and 6 days. There were 3 (13.0%) late miscarriages. The average GA at delivery was of 29.6 GW overall (26.3 GW and 31.1 GW in monochorionic and dichorionic pregnancies respectively). The overall fetal survival rate was 57.97% (40% and 66.7% in the group of monochorionic dichorionic pregnancies, respectively). However, neonatal mortality (<28 days) is 17.5%. CONCLUSION: GGG operated by fetoscopy for TTTS have a survival rate of three, at least 2 and at least 1 fetus of 21.7%, 69.6% and 82.6% respectively. The overall fetal survival rate is 59.97%. There is a tendency for better survival rates in dichorionic GGG compared to monochorionic GGG (P=0.079).

[Obstetrical ultrasound simulator as a tool for improving teaching strategies for beginners: Pilot study and review of the literature]. / La simulation pour améliorer l'apprentissage de l'échographie obstétricale chez les débutants : étude pilote et revue de la littérature.

OBJECTIVES: The aim of this study was to evaluate the obstetrical ultrasound simulator as an initiation tool for teaching obstetrical ultrasound scanning for beginners. METHODS: Twenty medical students with no experience in ultrasound scan (US) received a basic theoretical ultrasonography course on US principles and 2nd trimester biometrical measurements. The participants were then divided into 2 groups (A, B). Only group A received a practical 2nd trimester scan training session on the simulator where they were asked to determine fetal and placental position, and to take the 3 biometrical standardized measurements. Group B had the same training session but with a real ultrasound machine and a pregnant volunteer. The 2 groups were then asked to perform an US session on real patients (22 weeks) during which they had to do the same US study. The time needed to complete the whole scan was analyzed. The quality of the measurements was compared based on the previously published Objective Quality Criteria scoring. RESULTS: The mean total score was significantly (P=0.001) better for group A (14.3±1.4) compared to group B 10.3 (±2.75) for group A and B respectively. The time needed to accomplish the whole exam tended to be longer for group A (569±174s) compared to group A (479±104s) (P=0.18). CONCLUSIONS: The simulator might be a useful initiation tool to obstetric ultrasound for those who never practiced. It might prove a time sparing procedure in the training process and allow trainees to reach a basic practice level before performing examinations on actual patients.

Pulmonary stenosis in complicated monochorionic twin pregnancies: prevalence, management and outcome.

OBJECTIVE: To review prevalence, management and prognostic factors of pulmonary stenosis (PS) in monochorionic diamniotic (MCDA) pregnancies complicated by twin-to-twin transfusion syndrome (TTTS). METHODS: Retrospective study over the last 10 years in a single referral center. We reviewed fetal echocardiography data of all MC twin cases with diagnosis of isolated PS. We assessed fetoscopy characteristics of those that underwent laser coagulation. We collected data regarding perinatal outcome, neonatal echocardiography and cardiac management. RESULTS: We found 24 cases of isolated PS among 2091 MCDA pregnancies. Among 1052 complicated MCDA that underwent fetal laser surgery, 22 (2.09%) developed PS of which 20 were diagnosed prenatally. Two cases were diagnosed in uncomplicated MCDA pregnancies (0.2%). Four of 22 (18.18%) cases with TTTS showed in utero regression after laser treatment. Thirteen newborns (65%) required valvular dilatation. Peak systolic velocities in the pulmonary artery trunk (PSV-PA) at diagnosis and the interval between the diagnosis of TTTS and that of PS were significantly different (p < 0.001 and p = 0.05 respectively) between PS requiring cardiac intervention and those who did not. CONCLUSION: An elevated PSV-PA at the time of PS diagnosis and a short time-interval between fetoscopic laser surgery and PS diagnosis are predictive of the need for interventional treatment after birth.

Placental elastography in a murine intrauterine growth restriction model.

OBJECTIVE: To compare placental elasticity in normal versus intrauterine growth restriction (IUGR) murine pregnancies using shear wave elastography (SWE). METHODS: Intrauterine growth restriction was created by ligation of the left uterine artery of Sprague-Dawley rats on E17. Ultrasonography (US) and elastography were performed 2 days later on exteriorized horns after laparotomy. Biparietal diameter (BPD) and abdominal diameter (AD) were measured and compared in each horn. Placental elasticity of each placenta was compared in the right and left horns, respectively, using the Young's modulus, which increases with increasing stiffness of the tissue. RESULTS: Two hundred seventeen feto-placental units from 18 rats were included. Fetuses in the left ligated horn had smaller biometric measurements than those in the right horn (6.7 vs 7.2 mm, p < 0.001, and 9.2 vs 11.2 mm, p < 0.001 for BPD and AD, respectively). Mean fetal weight was lower in the pups from the left than the right horn (1.65 vs 2.11 g; p < 0.001). Mean (SD) Young's modulus was higher for placentas from the left than the right horn (11.7 ± 1.5 kPa vs 8.01 ± 3.8 kPa, respectively; p < 0.001), indicating increased stiffness in placentas from the left than the right horn. There was an inverse relationship between fetal weight and placental elasticity (r = 0.42; p < 0.001). CONCLUSION: Shear wave elastography may be used to provide quantitative elasticity measurements of the placenta. In our model, placentas from IUGR fetuses demonstrated greater stiffness, which correlated with the degree of fetal growth restriction.

Fetal urine biochemistry at 13-23 weeks of gestation in lower urinary tract obstruction: criteria for in-utero treatment.

OBJECTIVES: To assess the value of fetal urine biochemistry before 23 weeks of gestation in cases of lower urinary tract obstruction (LUTO) to refine prognosis and to select potential candidates for in-utero intervention. METHODS: This was a retrospective study including 72 cases of LUTO with fetal urine sampled before 23 weeks and assayed for total protein, ß-2-microglobulin, sodium, chloride, calcium, phosphorus, glucose and gamma-glutamyl transpeptidase (GGTP). Two groups were defined according to renal outcome: 1) bilateral renal dysplasia on histological examination or renal failure at birth; 2) normal postnatal renal function or histologically normal appearance of the kidneys. Correlations between fetal urinary biochemical markers and postnatal renal function were studied. RESULTS: LUTO was isolated in 56/72 (77.8%) cases and was associated with other malformations in 16/72 (22.2%) cases. High GGTP levels (236 IU/L vs 5 IU/L; P < 0.0001) were observed in fetal urine in the five cases of urodigestive fistula. A significant difference between outcome groups was observed for ß-2-microglobulin (P = 0.0017), sodium (P = 0.0008), chloride (P = 0.0028) and calcium (P = 0.0092) but not for protein, glucose or phosphorus. Sensitivity and specificity in defining a poor renal prognosis were 80.6% and 89% for ß-2-microglobulin, 61.3% and 100% for sodium and 64.5% and 100% for calcium, respectively. CONCLUSIONS: Fetal urinalysis before 23 weeks of gestation allowed distinction between three groups: 1) fetuses with normal urine biochemistry for which fetal therapy should be discussed; 2) fetuses with abnormal urine biochemistry for which prognosis for renal outcome is poor and for which the benefit of fetal therapy is likely to be compromised; 3) fetuses with urodigestive fistula.

[Second trimester growth restriction and underlying fetal anomalies]. / Retard de croissance intra-utérin du deuxième trimestre : malformations associées et syndromes sous-jacents.

OBJECTIVES: To determine the incidence of chromosomal abnormalities, syndromic association and fetal defects associated with second trimester fetal growth restriction (FGR) in a tertiary referral center. PATIENTS AND METHODS: Retrospective review of all cases referred between 14 and 27 weeks with an abdominal circumference (AC)<5(th) centile between 2008 and 2012. Multiple pregnancies were excluded. Medical records were retrieved to look for the presence of associated malformations, aneuploidy and outcomes. RESULTS: A total of 8626 fetuses had ultrasonographic examination between 14 and 27 weeks. Of these, there were 239 cases (2.8%) with evidence of FGR as based on AC measurement. Thirty-seven fetuses had an abnormal karyotype or an identified syndromic association (15%). The most common chromosomal defect was Trisomy 18 (10 cases, 4.2%), 67 had at least one associated morphological abnormality without aneuploidy or syndromic association (28%). Most common associated abnormalities were relative short femur (5%), omphalocele (5%) and gastroschisis (4%). Last 135 cases were isolated fetal growth retardation (5%). Maternal age was higher (33 yr ± 5 yr versus 31 yr ± 5.6 yr, P < 0.01) and the z-score for the AC lower (2.5 ± 1 versus 2.15 ± 0.6) in the group with abnormal karyotype or syndromic association than in the group without associated malformation. Amniotic fluid was more often increased in the group with an abnormal karyotype or associated malformation (14% and 17%) than in the group without malformations (0%, P < 0.01). DISCUSSION AND CONCLUSION: This study describes abnormalities and outcomes associated with second trimester fetal growth retardation in a large population of patients. Our results suggest that the absence of associated malformation, degree of growth restriction, maternal age and the amniotic fluid index may help in the prenatal management and counseling of this high risk population.