Accuracy of sonographic fetal weight estimation and prediction of birth-weight discordance in twin pregnancy: large single-center study.

OBJECTIVES: To determine the accuracy of sonographic fetal weight estimation in predicting birth weight (BW) and BW discordance in twin gestations, and to evaluate maternal and fetal characteristics that may affect the accuracy of this assessment. METHODS: This was a retrospective cohort study of all twins delivered at a single tertiary medical center between 2010 and 2021. Twin gestations for which sonographic estimation of fetal weight was performed within the week preceding delivery were included. Statistical analysis was performed to evaluate the strength of the correlation between sonographic estimated fetal weight (EFW) and BW, and to determine the impact of maternal and fetal factors on the accuracy of sonographic estimation. RESULTS: The study included 2154 twin pregnancies. There was a strong correlation between sonographic EFW and corresponding BW for all twins (r = 0.922; P < 0.001). Strong correlations were observed for both the presenting and non-presenting cotwin (r = 0.921 and r = 0.922, respectively; both P < 0.001), as well as the larger and smaller cotwin (r = 0.928 and r = 0.934, respectively; both P < 0.001). The overall mean ± SD absolute error of sonographic EFW was 7.41 ± 6.81%. This error was greater for the non-presenting cotwin compared with the presenting cotwin (7.99 ± 6.12% vs 7.17 ± 5.64%; P < 0.001), and for the smaller cotwin compared with the larger cotwin (8.56 ± 7.50% vs 6.58 ± 5.47%; P < 0.001). Advanced gestational age at scanning was correlated inversely with the mean absolute error of sonographic EFW. Multivariate logistic regression indicated that an earlier gestational age at scanning, being the non-presenting cotwin and being the smaller cotwin were independent risk factors for sonographic EFW inaccuracy. Pregnancies in which the presenting twin was estimated to be the smaller cotwin had twice the rate of false-positive BW discordance compared with pregnancies in which the presenting twin was estimated to be the larger cotwin (36.0% vs 13.0% for BW discordance > 15%, 35.0% vs 17.0% for BW discordance > 20% and 37.7% vs 12.1% for BW discordance > 25%; all P < 0.001). The error in sonographic EFW discordance was not related to chorionicity, the position of the presenting fetus or gestational age at the time of fetal weight estimation. CONCLUSIONS: Sonographic estimation of fetal weight within 7 days before delivery accurately predicts BW in twin pregnancy. Sonographic EFW accuracy is reduced for the non-presenting twin, the smaller cotwin and when delivery occurs at an earlier gestational age. Sonographic estimation of fetal weight discordance is less accurate when the presenting twin is the smaller cotwin. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Subarachnoid Space Measurements in Apparently Healthy Fetuses Using MR Imaging.

BACKGROUND AND PURPOSE: The fetal subarachnoid space size serves as an indicator of normal brain development. The subarachnoid space is commonly measured by an ultrasound examination. Introduction of MR imaging for fetal brain evaluation enables standardization of MR imaging-driven subarachnoid space parameters for a more accurate evaluation. This study aimed to determine the normal range of MR imaging-derived subarachnoid space size in fetuses according to gestational age. MATERIALS AND METHODS: A cross-sectional study based on a retrospective assessment of randomly selected brain MR images of apparently healthy fetuses performed between 2012 and 2020 at a large tertiary medical center was performed. Demographic data were collected from the mothers' medical records. Subarachnoid space size was measured at 10 reference points using the axial and coronal planes. Only MR imaging scans obtained between weeks 28 and 37 of pregnancy were included. Scans with low-quality images, multiple pregnancy, and cases with intracranial pathologic findings were excluded. RESULTS: Overall, 214 apparently healthy fetuses were included (mean maternal age, 31.2 [SD, 5.4] years). Good interobserver and intraobserver agreement was observed (intraclass correlation coefficient > 0.75 for all except 1 parameter). For each gestational week, the 3rd, 15th, 50th, 85th, and 97th percentiles of each subarachnoid space measurement were described. CONCLUSIONS: MR imaging-derived subarachnoid space values at a specific gestational age provide reproducible measurements, probably due to the high resolution of MR imaging and adherence to the true radiologic planes. Normal values for brain MR imaging could provide valuable reference information for assessing brain development, thus being an important tool in the decision-making process of both clinicians and parents.

Congenital hypotonia: systematic approach for prenatal detection.

OBJECTIVES: Congenital hypotonic conditions are rare and heterogeneous, and some are severely debilitating or lethal. Contrary to its prominent postnatal manifestation, the prenatal presentation of hypotonia is frequently subtle, inhibiting prenatal detection. We aimed to characterize the prenatal sonographic manifestation of congenital hypotonia throughout pregnancy, evaluate the yield of diagnostic tests and propose diagnostic models to increase its prenatal detection. METHODS: This was a retrospective observational study of singleton pregnancies with congenital hypotonia, diagnosed either prenatally or immediately after birth, at a single tertiary center between the years 2012 and 2020. Prenatally, hypotonia was diagnosed if a fetus showed sonographic or clinical signs suggestive of hypotonia and had a confirmed underlying genetic condition, or in the absence of a known genetic abnormality if the fetus exhibited multiple prominent signs suggestive of hypotonia. Postnatally, it was diagnosed in neonates displaying reduced muscle tone leading to reduced spontaneous movement, reduced swallowing or feeding difficulty. We reviewed the medical records of pregnant patients carrying fetuses subsequently diagnosed with congenital hypotonia and assessed the yield of ultrasound scans, fetal magnetic resonance imaging, computed tomography and genetic tests. The detection rate of sonographic signs suggesting fetal hypotonia was calculated. The prevalence of non-specific signs, including polyhydramnios, persistent breech presentation, intrauterine growth restriction and maternal perception of reduced fetal movement, were compared between the study group and the local liveborn singleton population. Potential detection rates of different theoretical semiotic diagnostic models, differing in the threshold for referral for a targeted scan, were assessed based on the cohort's data. RESULTS: The study group comprised 26 cases of congenital hypotonia, of which 10 (38.5%) were diagnosed prenatally, and the controls included 95 105 singleton live births, giving a prevalence of congenital hypotonia of 1:3658. Nuchal translucency thickness and the early anomaly scan at 13-17 weeks were normal in all 22 and 23 cases, respectively, in which this was performed. The mid-trimester scan performed at 19-25 weeks was abnormal in four of 24 (16.7%) cases. The overall prenatal detection rate of congenital hypotonic conditions in our cohort was 38.5%. Only cases which underwent a targeted scan were detected and, among the 16 cases which underwent this scan, the prenatal detection rate was 62.5% compared with 0% in pregnancies that did not undergo this scan (P = 0.003). An abnormal genetic diagnosis was obtained in 21 (80.8%) cases using the following modalities: chromosomal microarray analysis (CMA) in two (9.5%), whole-exome sequencing (WES) in 14 (66.7%) and methylation analysis in five (23.8%). CMA was abnormal in 8% (2/25) of the cases and WES detected a causative genetic mutation in 87.5% (14/16) of the cases in which these were performed. Comparison of non-specific signs in the study group with those in the local singleton population showed that hypotonic fetuses had significantly more polyhydramnios (64.0% vs 3.0%, P < 0.0001), persistent breech presentation (58.3% vs 4.2%, P < 0.0001), intrauterine growth restriction (30.8% vs 3.0%, P < 0.0001) and maternal perception of reduced fetal movement (32.0% vs 4.7%, P < 0.0001). Prenatally, the most commonly detected signs supporting a diagnosis of hypotonia were structural anomaly (62.5%, 10/16), reduced fetal movement (46.7%, 7/15), joint contractures (46.7%, 7/15) and undescended testes ≥ 30 weeks (42.9%, 3/7 males). Proposed diagnostic strategies that involved performing a targeted scan for a single non-specific ultrasound sign or two such signs, and then carrying out a comprehensive genetic evaluation for any additional sign, offered theoretical detection rates in our cohort of 88.5% and 57.7%, respectively. CONCLUSIONS: Congenital hypotonic conditions are rare and infrequently detected prenatally. Sonographic signs are visible from the late second trimester. A targeted scan increases prenatal detection significantly. Comprehensive genetic testing, especially WES, is the cornerstone of diagnosis in congenital hypotonia. Theoretical diagnostic models which may increase prenatal detection are provided. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Early Fetal Corpus Callosum: Demonstrating Normal Growth and Detecting Pathologies in Early Pregnancy.

BACKGROUND AND PURPOSE: A malformed corpus callosum carries a risk for abnormal neurodevelopment. The advent of high-frequency transducers offers the opportunity to assess corpus callosum development in early pregnancy. The aim of the study was to construct a reference chart of the fetal corpus callosum length on ultrasound between 13 and 19 weeks of gestation and to prospectively examine growth patterns in pathologic cases. MATERIALS AND METHODS: We performed a prospective cross-sectional study between 2020 and 2022 in well-dated, low-risk, singleton pregnancies between 13 and 19 weeks of gestation. A standardized image was obtained in the midsagittal plane. Imaging criteria were used as a confirmation of the early corpus callosum. Measurements were taken by 4 trained sonographers. Intra- and interobserver variability was assessed. Corpus callosum length in centiles were calculated for each gestational week. RESULTS: One hundred eighty-seven fetuses were included in the study. All cases met inclusion criteria. At 13 weeks of gestation, the margins of the early corpus callosum were sufficiently clear to be measured in 80% (20/25) of fetuses. A cubic polynomial regression model best described the correlation between corpus length and gestational age. The correlation coefficient (r 2) was 0.929 (P < .001). Intra- and interobserver variability had high interclass correlation coefficients (>0.99). Presented is the earliest published case of agenesis of corpus callosum and a case of dysgenetic corpus callosum in Rubinstein-Taybi syndrome. CONCLUSIONS: Provided is a nomogram of the early fetal corpus callosum. Applying imaging criteria helped to identify a case of complete agenesis of the corpus callosum as early as 14 weeks.

Esophageal atresia and tracheoesophageal fistula: prenatal sonographic manifestation from early to late pregnancy.

OBJECTIVE: Esophageal atresia and/or tracheoesophageal fistula (EA/TEF) remains one of the most frequently missed congenital anomalies prenatally. The aim of our study was to elucidate the sonographic manifestation of EA/TEF throughout pregnancy. METHODS: This was a retrospective study of data obtained from a tertiary center over a 12-year period. The prenatal ultrasound scans of fetuses with EA/TEF were assessed to determine the presence and timing of detection of three principal signs: small/absent stomach and worsening polyhydramnios, both of which were considered as 'suspected' EA/TEF, and esophageal pouch, which was considered as 'detected' EA/TEF. We assessed the yield of the early (14-16 weeks' gestation), routine mid-trimester (19-26 weeks) and third-trimester (≥ 27 weeks) anomaly scans in the prenatal diagnosis of EA/TEF. RESULTS: Seventy-five cases of EA/TEF with available ultrasound images were included in the study. A small/absent stomach was detected on the early anomaly scan in 3.6% of fetuses scanned, without a definitive diagnosis. On the mid-trimester scan, 19.4% of scanned cases were suspected and 4.3% were detected. On the third-trimester anomaly scan, 43.9% of scanned cases were suspected and 33.9% were detected. An additional case with an esophageal pouch was detected on magnetic resonance imaging (MRI) in the mid-trimester and a further two were detected on MRI in the third trimester. In total, 44.0% of cases of EA/TEF in our cohort were suspected, 33.3% were detected and 10.7% were suspected but, eventually, not detected prenatally. CONCLUSIONS: Prenatal diagnosis of EA/TEF on ultrasound is not feasible before the late second trimester. A small/absent stomach may be visualized as early as 15 weeks' gestation. Polyhydramnios does not develop before the mid-trimester. An esophageal pouch can be detected as early as 22 weeks on a targeted scan in suspected cases. The detection rates of all three signs increase with advancing pregnancy, peaking in the third trimester. The early and mid-trimester anomaly scans perform poorly as a screening and diagnostic test for EA/TEF. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Revisiting short- and long-term outcome after fetal first-trimester primary cytomegalovirus infection in relation to prenatal imaging findings.

OBJECTIVE: To determine the short- and long-term outcome of pregnancies with proven first-trimester fetal cytomegalovirus (CMV) infection in a large prospective cohort. METHODS: This was a prospective cohort study of pregnancies with documented primary maternal CMV infection in the first trimester and evidence of fetal infection, referred for further evaluation between January 2011 and January 2018. Maternal serological diagnosis of primary CMV infection was documented by seroconversion. Vertical CMV transmission was identified by amniocentesis with polymerase chain reaction (PCR) for the CMV genome. After birth, fetal infection was re-tested by PCR in neonatal urine or saliva samples. All patients underwent serial prenatal ultrasound scans and fetal magnetic resonance imaging (MRI) at 32-33 weeks' gestation. All neonates underwent ocular fundus examination, an ultrasound brain scan and hearing evaluation, and were followed periodically for a median of 2 years (range, 6 months to 10 years). Follow-up information was obtained from hospital charts and by telephone interviews with parents. The CMV-associated outcomes assessed were sensorineural hearing loss (SNHL), neurodevelopmental abnormality, composite clinical outcome (including SNHL and neurodevelopmental abnormality) and composite outcome (additionally including termination of pregnancy (TOP)). The association between prenatal ultrasound or MRI findings and abnormal outcome was assessed. RESULTS: Primary CMV infection in the first trimester occurred in 123 patients. The rate of an abnormal ultrasound finding was 30.9%, and the rate of an abnormal MRI finding was 30.1% overall and 14.1% in the subgroup of patients with normal ultrasound. Of the 85 patients with normal ultrasound, 12 had an abnormal MRI finding, of whom five (5.9%) had true anatomical findings. Fifteen patients decided to terminate the pregnancy owing to abnormal prenatal findings on either ultrasound or MRI. Overall, the rate of CMV-associated postnatal and childhood sequelae was 27.8%, with a rate of 16.7% for SNHL and 11.1% for neurodevelopmental abnormalities, mostly slight motor or verbal delay. Approximately half of the cases with CMV-associated sequelae did not have any abnormal prenatal imaging findings. Abnormal prenatal findings on ultrasound were not associated significantly with SNHL, neurodevelopmental delay or composite clinical outcome (P = 0.084, 0.109 and 0.176, respectively), but they were associated with the composite outcome including TOP (P < 0.001). We identified a non-significant trend for a higher rate of SNHL in the group with abnormal ultrasound than in those with normal ultrasound. For abnormal MRI findings, we found a correlation only with neurodevelopmental abnormality and composite outcome (P = 0.014 and P < 0.001, respectively). CONCLUSIONS: The risk of childhood sequelae after first-trimester fetal CMV infection is most often associated with abnormal prenatal imaging findings. However, normal imaging does not rule out the development of SNHL and minor neurodevelopmental abnormalities. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Immediate postpartum ultrasound evaluation for suspected retained placental tissue in patients undergoing manual removal of placenta.

OBJECTIVES: Approximately 1% of term deliveries are complicated by retained products of conception. Untreated, this condition may cause bleeding, infection and intrauterine adhesions. This study assessed whether performing routine bedside uterine ultrasound immediately after manual removal of the placenta reduced the occurrence of undiagnosed, retained products of conception and its associated complications. STUDY DESIGN: A retrospective study was conducted using the records of patients who delivered and underwent manual removal of placenta at a single obstetrics center over a 6-year period. The outcomes of patients who were assessed using immediate bedside ultrasound were compared to a similar group who were treated based on clinical evaluation alone. All patients underwent ultrasound examination prior to discharge. Outcome variables included the rate of additional interventions (medical or surgical), abnormal pre-discharge uterine ultrasound findings, postpartum hemorrhage rate, puerperal fever and length of hospital stay. RESULTS: A total of 399 charts were reviewed. Immediate post-procedural ultrasound was performed in 235 patients. The remaining 164 women did not undergo immediate post-procedural ultrasound. All patients underwent an ultrasound examination prior to discharge. Among the patients who had an immediate post-procedural ultrasound, 12 (5.1%) received immediate re-intervention (2 methergine, 6 curettage and 4 manual uterine revision) vs. no intervention in the second group (p<0.001). No statistically significant difference was found between the group of patients who had immediate post-procedural ultrasound and those who did not, in the rates of postpartum hemorrhage (3.1% vs. 0.7%, p=0.13), abnormal ultrasound findings prior to discharge (14.9% vs. 14.8%, p=0.96) or additional late intervention (7.2% vs. 7.9%, p=0.79), respectively. CONCLUSIONS: Our findings suggest that immediate, bedside uterine ultrasound examination after manual removal of placenta might not change patient outcomes. Furthermore, it might increase unnecessary interventions. Further studies are needed to prospectively assess the benefit of routine uterine ultrasound examination after manual removal of placenta.

ELNES study of chemical solution deposited SrO(SrTiO(3))(n) Ruddlesden-Popper films: experiment and simulation.

This article analyzes electron energy-loss near-edge fine structures of the SrO(SrTiO(3))(n=1) Ruddlesden-Popper system and of the parent compounds SrTiO(3) and SrO by comparison with first principles calculations. For that, the fine structures of chemical solution deposited Ruddlesden-Popper films have been experimentally recorded by means of transmission electron microscopy. Moreover, density of states computations using an all-electron density-functional code have been performed. It is shown that the appearance and shape of the experimental O-K and Ti-L(2,3) fine structure features result from the crystallography-dependent electronic structure of the investigated oxides, which display technologically interesting dielectric as well as lattice-structural properties.

On the applicability of high frequency acoustic shear mode biosensing in view of thickness limitations set by the film resonance.

The IC-compatible thin film bulk acoustic resonator (FBAR) technology has made it possible to move the thickness excited shear mode sensing of biological layers into a new sensing regime using substantially higher operation frequencies than the conventionally used quartz crystal microbalance (QCM). The limitations of the linear range set by the film resonance using viscoelastic protein films are here for the first time addressed specifically for FBARs operating at 700 MHz up to 1.5 GHz. Two types of protein multilayer sensing were employed; one utilizing alternating layers of streptavidin and biotinated BSA and the other using stepwise cross-linking of fibrinogen with EDC/NHS activation of its carboxyl groups. In both cases the number of protein layers within the linear regime is well above the number of protein layers usually used in biosensor applications, further verifying the applicability of the FBAR as a biosensor. Theoretical calculations are also presented using well established physical models to illustrate the expected behavior of the FBAR sensor, in view of both the frequency and the dissipation shifts.

Switching Ti valence in SrTiO3 by a dc electric field.

A (001) SrTiO3 wafer has been investigated in situ at room temperature under application of a static electric field of varying polarity by fluorescence x-ray absorption near edge structure (XANES) analysis at the Sr-K and Ti-K absorption edges. The XANES spectra show a clear shift of the Ti-K absorption edge energy. The shift is attributed to a change of the Ti valence state in a volume invoked by diffusion of the oxygen ions and vacancies. No shift was observed for the Sr-K absorption edge energy. Theoretical calculations support these findings.

The referral problem in the field of alcohol abuse.

This paper reports on referral sources and the disposition of 409 problem drinkers who were contacted over a two-year period for participation in a 17-week alcohol abuse treatment program. A longitudinal follow-up design was used with 103 persons to evaluate various learning-based techniques in moderating their drinking habits. Referrals were analyzed by source (75% were legal referrals), percentage completing the program (70%, 72%, and 69% for self, legal, and mental health referrals), and "success" at one year. Legal referrals reported a significantly smaller pretreatment alcohol intake than self and mental health referrals. However, the decrease in alcohol intake for legal and nonlegal referrals were almost identical. The stigma of alcoholism as a disease and the coercion associated with referral by legal agencies were considered to be factors in acceptance of treatment and in treatment outcome.

Comments on the relationship between locus of control and alcohol abuse.

Studies that report conflicting relationships between alcohol abuse and locus of control were reviewed. Possible explanations for the results were presented, as were data that indicate that locus of control may be related to age and to social desirability, but not to alcohol abuse. It was suggested that in the absence of a clear theoretical rationale for relating locus of control to alcohol abuse, the contradictory findings are not surprising.