Evaluation of screening performance of first-trimester competing-risks prediction model for small-for-gestational age in Asian population

OBJECTIVE

To examine the external validity of the Fetal Medicine Foundation (FMF) competing-risks model for the prediction of small-for-gestational age (SGA) at 11-14 weeks' gestation in an Asian population.

METHODS

This was a secondary analysis of a multicenter prospective cohort study in 10 120 women with a singleton pregnancy undergoing routine assessment at 11-14 weeks' gestation. We applied the FMF competing-risks model for the first-trimester prediction of SGA, combining maternal characteristics and medical history with measurements of mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI) and serum placental growth factor (PlGF) concentration. We calculated risks for different cut-offs of birth-weight percentile (< 10th , < 5th or < 3rd percentile) and gestational age at delivery (< 37 weeks (preterm SGA) or SGA at any gestational age). Predictive performance was examined in terms of discrimination and calibration.

RESULTS

The predictive performance of the competing-risks model for SGA was similar to that reported in the original FMF study. Specifically, the combination of maternal factors with MAP, UtA-PI and PlGF yielded the best performance for the prediction of preterm SGA with birth weight < 10th percentile (SGA < 10th ) and preterm SGA with birth weight < 5th percentile (SGA < 5th ), with areas under the receiver-operating-characteristics curve (AUCs) of 0.765 (95% CI, 0.720-0.809) and 0.789 (95% CI, 0.736-0.841), respectively. Combining maternal factors with MAP and PlGF yielded the best model for predicting preterm SGA with birth weight < 3rd percentile (SGA < 3rd ) (AUC, 0.797 (95% CI, 0.744-0.850)). After excluding cases with pre-eclampsia, the combination of maternal factors with MAP, UtA-PI and PlGF yielded the best performance for the prediction of preterm SGA < 10th and preterm SGA < 5th , with AUCs of 0.743 (95% CI, 0.691-0.795) and 0.762 (95% CI, 0.700-0.824), respectively. However, the best model for predicting preterm SGA < 3rd without pre-eclampsia was the combination of maternal factors and PlGF (AUC, 0.786 (95% CI, 0.723-0.849)). The FMF competing-risks model including maternal factors, MAP, UtA-PI and PlGF achieved detection rates of 42.2%, 47.3% and 48.1%, at a fixed false-positive rate of 10%, for the prediction of preterm SGA < 10th , preterm SGA < 5th and preterm SGA < 3rd , respectively. The calibration of the model was satisfactory.

CONCLUSION

The screening performance of the FMF first-trimester competing-risks model for SGA in a large, independent cohort of Asian women is comparable with that reported in the original FMF study in a mixed European population. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Changing the standardised obstetric care by expanded carrier screening and counselling: a multicentre prospective cohort study

BACKGROUND

Expanded genetic screening before conception or during prenatal care can provide a more comprehensive evaluation of heritable fetal diseases. This study aimed to provide a large cohort to evaluate the significance of expanded carrier screening and to consolidate the role of expanded genetic screening in prenatal care.

METHODS

This multicentre, retrospective cohort study was conducted between 31 December 2019 and 21 July 2022. A screening panel containing 302 genes and next-generation sequencing were used for the evaluation. The patients were referred from obstetric clinics, infertility centres and medical centres. Genetic counsellors conducted consultation for at least 15 min before and after screening.

RESULTS

A total of 1587 patients were screened, and 653 pairs were identified. Among the couples who underwent the screening, 62 (9.49%) had pathogenic variants detected on the same genes. In total, 212 pathogenic genes were identified in this study. A total of 1173 participants carried at least one mutated gene, with a positive screening rate of 73.91%. Among the pathogenic variants that were screened, the gene encoding gap junction beta-2 (GJB2) exhibited the highest prevalence, amounting to 19.85%.

CONCLUSION

Next-generation sequencing carrier screening provided additional information that may alter prenatal obstetric care by 9.49%. Pan-ethnic genetic screening and counselling should be suggested for couples of fertile age.

Corrigendum: real-world management of abnormal scarring using topical silicone gel: expert consensus and case series from the Asian SCARS Expert Group

[This corrects the article DOI: 10.7573/dic.2023-4-3.].

Real-world management of abnormal scarring using topical silicone gel: expert consensus and case series from the Asian SCARS Expert Group

Preventing abnormal scar formation and correcting non-aesthetic mature scars are important to prevent physical and psychosocial consequences of abnormal scarring. Evidence-based guidelines for scar management in Asian patients recommend first-line silicone-based products. Dermatix®* Ultra and Dermatix Ultra Kids are topical silicone gels containing a vitamin C ester that helps lighten scar tissue. Herein, we report a case series including patients with hypertrophic and keloid scars treated with Dermatix, showing that Dermatix is effective for scar treatment and prevention, as well as expert consensus supporting the safe and effective use of Dermatix.

Nonlinear Stiffness and Nonlinear Damping in Atomically Thin MoS2 Nanomechanical Resonators

We report on experimental measurements and quantitative analyses of nonlinear dynamic characteristics in ultimately thin nanomechanical resonators built upon single-layer, bilayer, and trilayer (1L, 2L, and 3L) molybdenum disulfide (MoS₂) vibrating drumhead membranes. This synergistic study with calibrated measurements and analytical modeling on observed nonlinear responses has led to the determination of nonlinear damping and stiffness coefficients at cubic and quintic orders for these two-dimensional (2D) resonators operating in the very high frequency (VHF) band (up to ∼90 MHz). We find that the quintic force can be ∼20% of the Duffing force at larger amplitudes, and thus, it generally cannot be ignored in a nonlinear dynamics analysis. This study provides the first quantification of nonlinear damping and frequency detuning characteristics in 2D semiconductor nanomechanical resonators and elucidates their origins and dependency on engineerable parameters, setting a foundation for future exploration and utilization of the rich nonlinear dynamics in 2D nanomechanical systems.

Risk factors for anxiety and depression among pregnant women during the COVID-19 pandemic: Results of a web-based multinational cross-sectional study

OBJECTIVE

To assess risk factors for anxiety and depression among pregnant women during the COVID-19 pandemic using Mind-COVID, a prospective cross-sectional study that compares outcomes in middle-income economies and high-income economies.

METHODS

A total of 7102 pregnant women from 12 high-income economies and nine middle-income economies were included. The web-based survey used two standardized instruments, General Anxiety Disorder-7 (GAD-7) and Patient Health Questionnaire-9 (PHQ-9).

RESULT

Pregnant women in high-income economies reported higher PHQ-9 (0.18 standard deviation [SD], P < 0.001) and GAD-7 (0.08 SD, P = 0.005) scores than those living in middle-income economies. Multivariate regression analysis showed that increasing PHQ-9 and GAD-7 scales were associated with mental health problems during pregnancy and the need for psychiatric treatment before pregnancy. PHQ-9 was associated with a feeling of burden related to restrictions in social distancing, and access to leisure activities. GAD-7 scores were associated with a pregnancy-related complication, fear of adverse outcomes in children related to COVID-19, and feeling of burden related to finances.

CONCLUSIONS

According to this study, the imposed public health measures and hospital restrictions have left pregnant women more vulnerable during these difficult times. Adequate partner and family support during pregnancy and childbirth can be one of the most important protective factors against anxiety and depression, regardless of national economic status.

Combinatorial Analysis of Circulating Biomarkers and Maternal Characteristics for Preeclampsia Prediction in the First and Third Trimesters in Asia

We aim to establish a prediction model for pregnancy outcomes through a combinatorial analysis of circulating biomarkers and maternal characteristics to effectively identify pregnant women with higher risks of preeclampsia in the first and third trimesters within the Asian population. A total of two hundred and twelve pregnant women were screened for preeclampsia through a multicenter study conducted in four recruiting centers in Taiwan from 2017 to 2020. In addition, serum levels of sFlt-1/PlGF ratio, miR-181a, miR-210 and miR-223 were measured and transformed into multiples of the median. We thus further developed statistically validated algorithmic models by designing combinations of different maternal characteristics and biomarker levels. Through the performance of the training cohort (0.848 AUC, 0.73−0.96 95% CI, 80% sensitivity, 85% specificity, p < 0.001) and the validation cohort (0.852 AUC, 0.74−0.98 95% CI, 75% sensitivity, 87% specificity, p < 0.001) from one hundred and fifty-two women with a combination of miR-210, miR-181a and BMI, we established a preeclampsia prediction model for the first trimester. We successfully identified pregnant women with higher risks of preeclampsia in the first and third trimesters in the Asian population using the established prediction models that utilized combinatorial analysis of circulating biomarkers and maternal characteristics.

Human amniotic fluid stem cell therapy can help regain bladder function in type 2 diabetic rats

BACKGROUND

Diabetes mellitus (DM) is a serious and growing global health burden. It is estimated that 80% of diabetic patients have micturition problems such as poor emptying, urinary incontinence, urgency, and urgency incontinence. Patients with diabetic bladder dysfunction are often resistant to currently available therapies. It is necessary to develop new and effective treatment methods.

AIM

To examine the therapeutic effect of human amniotic fluid stem cells (hAFSCs) therapy on bladder dysfunction in a type 2 diabetic rat model.

METHODS

Sixty female Sprague-Dawley rats were divided into five groups: Group 1, normal-diet control (control); group 2, high-fat diet (HFD); group 3, HFD plus streptozotocin-induced DM (DM); group 4, DM plus insulin treatment (DM + insulin); group 5, DM plus hAFSCs injection via tail vein (DM + hAFSCs). Conscious cystometric studies were done at 4 and 12 wk after insulin or hAFSCs treatment to measure peak voiding pressure, voided volume, intercontraction interval, bladder capacity, and residual volume. Immunoreactivities and/or mRNA expression of muscarinic receptors, nerve growth factor (NGF), and sensory nerve markers in the bladder and insulin, MafA, and pancreatic-duodenal homeobox-1 (PDX-1) in pancreatic beta cells were studied.

RESULTS

Compared with DM rats, insulin but not hAFSCs treatment could reduce the bladder weight and improve the voided volume, intercontraction interval, bladder capacity, and residual volume (P < 0.05). However, both insulin and hAFSCs treatment could help to regain the blood glucose and bladder functions to the levels near controls (P > 0.05). The immunoreactivities and mRNA expression of M2- and M3-muscarinic receptors (M2 and M3) were increased mainly at 4 wk (P < 0.05), while the number of beta cells in islets and the immunoreactivities and/or mRNA of NGF, calcitonin gene-related peptide (CGRP), substance P, insulin, MafA, and PDX-1 were decreased in DM rats (P < 0.05). However, insulin and hAFSCs treatment could help to regain the expression of M2, M3, NGF, CGRP, substance P, MafA, and PDX-1 to near the levels of controls at 4 and/or 12 wk (P > 0.05).

CONCLUSION

Insulin but not hAFSCs therapy can recover the bladder dysfunction caused by DM; however, hAFSCs and insulin therapy can help to regain bladder function to near the levels of control.

The Exploration of miRNAs From Porcine Fallopian Tube Stem Cells on Porcine Oocytes

Fallopian tube is essential to fertilization and embryonic development. Extracellular vesicles (EVs) from Fallopian tube containing biological regulatory factors, such as lipids, proteins and microRNAs (miRNAs) serve as the key role. At present, studies on oocytes from porcine oviduct and components from EVs remain limited. We aim to explore the effect of EVs secreted by porcine fallopian tube stem cells (PFTSCs) on oocyte. When the fifth-generation PFTSCs reached 80–90% of confluency, the pig in vitro maturation medium was utilized, and the conditioned medium collected for oocyte incubations. To realize the functions of EVs, several proteins were used to determine whether extracted EVs were cell-free. Field emission scanning electron microscope and nanoparticle tracking analyzer were used to observe the morphology. By next generation sequencing, 267 miRNAs were identified, and those with higher expression were selected to analyze the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment maps. The selected miR-152-3p, miR-148a-3p, miR-320a-3p, let-7f-5p, and miR-22-3p, were predicted to target Cepb1 gene affecting MAPK pathway. Of the five miRNAs, miR-320a-3p showed significant difference in maturation rate in vitro maturation. The blastocyst rate of pig embryos was also significantly enhanced by adding 50 nM miR-320a-3p. In vitro culture with miR-320a-3p, the blastocyst rate was significantly higher, but the cleavage rate and cell numbers were not. The CM of PFTSCs effectively improves porcine oocyte development. The miRNAs in EVs are sequenced and identified. miR-320a-3p not only helps the maturation, but also increases the blastocyst rates.

Human amniotic fluid stem cells can alleviate detrusor dysfunction caused by bladder outlet obstruction in rats

The present study examined whether bladder detrusor dysfunction due to partial bladder outlet obstruction (pBOO) could be improved after the treatment of human amniotic fluid stem cells (hAFSCs). 72 female rats were grouped into sham operation, pBOO, and pBOO with hAFSCs treatment (pBOO + hAFSCs) for in vitro and in vivo studies. Bladder weight, bladder wall thickness, the ratio of collagen to smooth muscle and the levels of positive CD11b/c and HIS48 cells was significantly increased after pBOO but improved after hAFSCs treatment. Cystometries showed impaired bladder function after pBOO. Protein and mRNA levels of hypoxia inducible factor-1α, CCL2, interleukin-1β, transforming growth factor-β1 (TGF-β1), connective tissue growth factor (CTGF), α-smooth muscle actin, collagen I and collagen III were increased at 2 and/or 6 weeks, but proteins and mRNA expressions of protein gene product 9.5 were decreased at 2 and 6 weeks after pBOO. These abnormalities were improved after hAFSCs treatment. The expressions of TGF-β1 and CTGF in cultured detrusor cells of pBOO rats were increased but were improved after hAFSCs treatment. The present results showed hAFSCs treatment could improve bladder detrusor dysfunction in pBOO rats, which may be related to the reduction of inflammatory and pro-fibrotic markers in detrusor muscle cells.

Maternal outcome of selective feticide due to fetal anomaly in late trimester: A retrospective 10 years' experience in Taiwan

BACKGROUND

Feticide was suggested to avoid delivering children with abnormalities. Recently, twin pregnancies have increased. Selective feticide was proposed to achieve a good outcome of pregnancy. This study aimed to evaluate the performance of feticide in twin pregnancy with fetal anomaly.

METHODS

This was a retrospective study enrolled from 2009 to 2018. A total of 68 pregnancies with fetal anomalies received feticide. Potassium chloride was injected into the left ventricle to induce fetal asystole. Maternal and fetal characteristics of 16 dichorionic twins were documented to compare before and after 24th gestational week.

RESULTS

All pregnant women received feticide without any maternal or fetal complication. The reasons for choosing feticide were divided into four groups, including morphologic defect (61.8%), genetic-chromosomal abnormality (30.9%), obstetrical complication (5.9%), and maternal request (1.5%). Mean gestational age at delivery was significantly higher in dichorionic twins who underwent selective feticide before than after 24th gestational week (36.7 vs 33.4, p = 0.04).

CONCLUSION

Intracardiac injection of potassium chloride was effective for feticide and safe for mothers and fetuses. Selective feticide served as an alternative approach for twin pregnancy with fetal anomaly after sufficient discussion.

The impact of prenatal screening tests on prenatal diagnosis in Taiwan from 2006 to 2019: a regional cohort study

BACKGROUND

The purpose of this study is to evaluate the impact of prenatal screening tests on prenatal diagnosis in Taiwan's 14 years from 2006 to 2019.

METHODS

The prenatal screening methods evolved from the second-trimester serum screening to combined first-trimester screening (cFTS) and then followed by the non-invasive cell-free DNA prenatal test (NIPT). The data used by the Department of Statistics, the Ministry of Health and Welfare and Department of Household Registration, Ministry of the Interior public website.

RESULTS

This regional registry-based cohort retrospective study examined a total of 2,775,792 births from January 2006 to December 2019. The proportion of advanced maternal age (AMA) pregnancies increased from 11.63% in 2006 to 30.94% in 2019. Overall, invasive diagnostic testing was used in 87.22% of AMA pregnancies. The prenatal detection rate of trisomy 21 and 18 increased from 74.1% and 83.3% in 2006 to 96.9% and 98.8% in 2019, respectively.

CONCLUSION

During the second-trimester and cFTS periods, the percentage of AMA pregnancies increased every year and the number of invasive procedures also accompany with increased percentage of AMA. However, during the period that NIPT were implemented, the percentage of invasive procedures decreased.

Difficulties of Prenatal Genetic Counseling for a Subsequent Child in a Family With Multiple Genetic Variations

Many parents with a disabled child caused by a genetic condition appreciate the option of prenatal genetic diagnosis to understand the chance of recurrence in a future pregnancy. Genome-wide tests, such as chromosomal microarray analysis and whole-exome sequencing, have been increasingly used for prenatal diagnosis, but prenatal counseling can be challenging due to the complexity of genomic data. This situation is further complicated by incidental findings of additional genetic variations in subsequent pregnancies. Here, we report the prenatal identification of a baby with a MECP2 missense variant and 15q11.2 microduplication in a family that has had a child with developmental and epileptic encephalopathy caused by a de novo KCNQ2 variant. An extended segregation analysis including extended relatives, in addition to the parents, was carried out to provide further information for genetic counseling. This case illustrates the challenges of prenatal counseling and highlights the need to understand the clinical and ethical implications of genome-wide tests.

Reply to: Noninvasive prenatal testing for DiGeorge syndrome: is it ready for clinical practice?

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Human amniotic fluid stem cells can improve cerebral vascular remodelling and neurological function after focal cerebral ischaemia in diabetic rats

Diabetes causes vascular injury and carries a high risk of ischaemic stroke. Human amniotic fluid stem cells (hAFSCs) can enhance cerebral vascular remodelling and have the potential to improve neurological function after stroke in diabetic rats. Five groups of female rats were examined: (1) normal control, (2) type 1 diabetic (T1DM) rats induced by streptozotocin injection (DM), (3) non‐DM rats receiving 60‐minute middle cerebral artery occlusion (MCAO), (4) T1DM rats receiving 60‐minute MCAO (DM + MCAO) and (5) T1DM rats receiving 60‐minute MCAO and injection with 5 × 10⁶ hAFSCs at 3 h after MCAO (DM + MCAO + hAFSCs). Neurological function was examined before, and at 1, 7, 14, 21 and 28 days, and cerebral infarction volume and haemorrhage, cerebral vascular density, angiogenesis and inflammatory were examined at 7 and 28 days after MCAO. hAFSCs treatment caused a significant improvement of neurological dysfunction, infarction volume, blood‐brain barrier leakage, cerebral arterial density, vascular density and angiogenesis and a reduction of brain haemorrhage and inflammation compared with non‐treatment. Our results showed that the effect of hAFSCs treatment against focal cerebral ischaemia may act through the recovery of vascular remodelling and angiogenesis and the reduction of inflammation in ischaemic brain.

Taiwanese Clinical Experience with Noninvasive Prenatal Testing for DiGeorge Syndrome

OBJECTIVE

DiGeorge syndrome (DGS) is associated with microdeletions of chromosome 22q11. It is the second most common cause of congenital heart disease and is an important consideration whenever a conotruncal cardiac anomaly is identified. The availability of noninvasive prenatal testing (NIPT) is altering the practice of prenatal genetics and maternal-fetal medicine, resulting in a decline in invasive testing. Antenatal ultrasound and other biomarkers have their own limitation. NIPT was proposed to screen DGS with cell-free DNA in Taiwan. Here, we present our experience of prenatal diagnosis of DGS in our center.

METHODS

This was a retrospective study between November 1, 2019, and August 31, 2020, in Taiwan. Data were collected from 7,826 pregnant women self-referred for DGS screening with massive parallel shotgun sequencing-based NIPT. High-risk cases subsequently received amniocentesis for array comparative genomic hybridization (aCGH) to confirm the diagnosis. Characteristics of pregnancies were documented when participants received the test. Report of NIPT was completed 2 weeks after the test. Follow-up on high-risk cases was completed by telephone interview on January 30, 2021.

RESULTS

Thirteen cases showed high risk by NIPT, and 7 cases were confirmed by aCGH. The sensitivity and specificity were 100% (95% confidence interval [CI] 64.57-100.00%) and 99.92% (95% CI 99.83-99.96%). The prevalence of DGS was 1 in 1,118 pregnancies. The positive predictive rate was 53.85% (95% CI 29.14-76.79%). One true positive (TP) showed US anomaly, and 5 TPs selected termination.

DISCUSSION/CONCLUSION

NIPT demonstrated good performance in DGS screening. Detection of 22q11.2 deletion could be combined with routine screening to facilitate proper intervention.

Fallopian tube stem cell medium of porcine and bovine: In vitro regenerative effect on maturation and parthenogenesis of porcine oocytes

Assisted reproductive technology (ART) has been widely developed over the decades. This advanced technology has shown efficacy in the conception and breeding of an animal. However, several issues such as polyspermy, low maturation rate, and low development rate in vitro remain unresolved. Fallopian tube derived cells are proposed to promote the maturation and development of oocyte. This study aims to characterize porcine (PFTSC) and bovine fallopian tube stem cell (BFTSC) while comparing allogeneic and xenogeneic paracrine effects on porcine oocyte. FTSC of Taiwan yellow cattle (B. indicus) and porcine (Landrace x Yorkshire dam x Duroc) were isolated and identified. Conditioned media (Medium 199 or PZM-3) from porcine and bovine was collected and added to porcine cells during in vitro maturation (IVM) and in vitro culture (IVC). Both PFTSC and BFTSC expressed little CD44, CD105, and CD4. Both cells were induced to transform into chondrocytes, very few cells gave rise to osteocytes and adipocytes. IVM test showed a significant elevation of maturation rate in both groups (Porcine: 66.5 ± 3.5% > 55.9 ± 1.7%, p < .05; Bovine: 68.9 ± 2.3% > 55.9 ± 1.7%, p < .05). IVC test demonstrated markedly reduction of blastocyst in both groups. In a diluted conditioned medium with different concentration, 25% and 50% PFTSC showed a decrease in blastocyst rate which is significantly different, but BFTSC demonstrated no significant difference. PFTSC and BFTSC possessed properties of stem cells. Conditioned media from both PFTSC and BFTSC could improve maturation rate but not blastocyst rate in vitro.

The association between weight gain at different stages of pregnancy and risk of gestational diabetes mellitus

AIMS/INTRODUCTION

Women with excessive gestational weight gain (GWG) are at a higher risk for complications during pregnancy, such as preeclampsia. However, the association between excessive GWG and gestational diabetes mellitus (GDM) remains unclear.

MATERIALS AND METHODS

We retrospectively reviewed 8,352 women from our obstetric database with singleton pregnancies who gave birth after 28 completed weeks of gestation between January 1, 2012, and December 31, 2016, excluding pregnancies complicated by fetal anomalies, fetal death, and overt diabetes. Diagnosis of GDM was based on the criteria recommended by the International Association of Diabetes and Pregnancy Study Groups. We used two classification methods to define excessive GWG: a weight gain above the 90th percentile of the population, or exceeding the upper range recommended by the Institute of Medicine, stratified by pre-pregnancy body mass index. Statistical analysis was performed using multiple logistic regression to determine the association between excessive GWG and the risk of GDM.

RESULTS

Overall, 1,129 women (13.5%) were diagnosed with GDM. There was no difference in GWG between women with and without GDM in the first trimester and before GDM screening. Women with GDM had significantly less GWG in the second trimester, after GDM screening, and throughout the whole gestation than women without GDM. No correlation was found between excessive GWG in the first and second trimesters, before GDM screening, and the later development of GDM.

CONCLUSIONS

Our results indicate that excessive GWG prior to GDM screening is not associated with an increased risk of GDM.

Prenatal diagnosis and management of monozygotic twins discordant for severe fetal abnormalities

OBJECTIVE

We present prenatal diagnosis and management of monozygotic (MZ) twins discordant for severe fetal abnormalities.

CASE REPORT

A 36-year-old woman underwent amniocentesis at 18 weeks of gestation because of advanced maternal age, and hydrops fetalis, a giant cystic hygroma of 5 × 3.5 cm and left hydronephrosis in a co-twin. The other co-twin was structurally normal. Amniocentesis revealed a karyotype of 46,XY in both co-twins. Simultaneous polymorphic DNA marker analysis using the DNAs extracted from maternal blood and uncultured amniocytes confirmed MZ twinning. The woman underwent a successful selective fetal reduction by radiofrequency ablation at 22 weeks of gestation. At 28 weeks of gestation, premature rupture of membranes occurred, and a 1280-g normal male baby and a 275-g dead malformed co-twin were delivered. The normal co-twin was phenotypically normal and was doing well at age seven weeks.

CONCLUSIONS

Prenatal diagnosis of MZ twins discordant for structural abnormalities should include a differential diagnosis of MZ twinning, and a zygosity test is necessary under such a circumstance.

A landscape of micronutrient status in women through the reproductive years: Insights from seven regions in Asia

Optimal micronutrient status is critical to the health of women, particularly during their reproductive years. A woman’s health and nutritional status during the preconception stage thus has significant implications for pregnancy outcomes and her offspring’s health later in life. In this review, we evaluated micronutrient intakes and status (iron, folate, and vitamin B12) of women in their reproductive years and during pregnancy, along with associated health consequences and dietary causes, across seven regions in Asia, namely, Hong Kong, Indonesia, the Philippines, Singapore, Taiwan, Thailand, and Vietnam. A structured literature search, targeting peer-reviewed publication databases, as well as data from international and national sources in the public domain, was conducted. Our review of the nutritional landscape demonstrates that micronutrient deficiency–related conditions, especially anemia and its associated health consequences, are common among Asian women of reproductive age, yet the dietary causes are poorly studied. Inadequate or borderline dietary intake of micronutrients and low consumption of micronutrient supplements were evident, despite existing recommendations, food fortification, and supplementation strategies. Evaluation of current programs through nutrition monitoring and improvement of supplementation strategies, such as supplementing with multiple micronutrients, alongside food-based programs, will help better support the health of women through their reproductive years.

From non-invasive to invasive fetal therapy: A comprehensive review and current update

"Fetus as patient" indicates fundamental concept of fetal therapy. With advance in maternal serum analysis and fetal imaging, prenatal screening has become standard of care. Accurate diagnosis in early gestation allows intervention to reverse pathophysiology and delay progression immediately. Non-invasive, minimally invasive and invasive therapies demonstrate their therapeutic potential in certain diseases. Recently, stem cell and gene therapies have been developed to avoid irreversible impairment. To elevate efficacy of treatment modality, extensive studies should be conducted according to regulatory authority. Striking a balance between scientific and ethical integrity is essential, so long-term follow up should be arranged for protecting mother and fetus.

Real-World Practices and Attitudes Towards Intimate Self- Care: Results From An International Women's Survey

OBJECTIVE

Vulvovaginal health is important to women's overall health, fertility, sexuality, self-perception, self-confidence and intimacy. It is important to identify the existing perceptions and levels of knowledge about intimate care practices from women in different countries, and with different cultures, religions, and perspectives to help women overcome barriers to optimal intimate care.

METHODS

An anonymous online survey about general and intimate hygiene routines/habits was distributed across 10 countries (England, France, Germany, Italy, Portugal, Russia, China, Philippines, Taiwan, Thailand). The sample consisted of around 10,000 women (aged 18 to 60 years) recruited through an online panel.

RESULTS

The survey indicates that for many women, cleaning the intimate area is not just about hygiene, but also about taking care of themselves. Intimate care practices, performed daily, varies widely among the countries (from 38% to 91%). Italy, Philippines Portugal, Russia and Thailand were the countries with higher percentage. Intimate care is mainly associated with hygiene and health benefit, but interestingly women engage in intimate care more often with age. Most women worldwide are comfortable talking about female genitalia but still consider it a taboo topic, particularly among younger generations. Asian countries continue to carry negative connotations.

CONCLUSIONS

This survey is the first of its kind for number of women involved in this research and for multi-cultural design. Women perceive that practicing intimate care positively impacts their health and wellbeing. However, intimate care is still not one of the most frequent daily routines for many women.

Risk factors and adverse maternal and perinatal outcomes for women with dichorionic twin pregnancies complicated by gestational diabetes mellitus: A retrospective cross-sectional study

AIMS/INTRODUCTION

The association between gestational diabetes mellitus (GDM) and adverse maternal and perinatal outcomes in twin pregnancies remains unclear. This study was undertaken to highlight risk factors for GDM in women with dichorionic (DC) twins, and to determine the association between GDM DC twins and adverse maternal and perinatal outcomes in a large homogeneous Taiwanese population.

MATERIALS AND METHODS

A retrospective cross-sectional study was carried out on 645 women with DC twins, excluding pregnancies complicated by one or both fetuses with demise (n = 22) or congenital anomalies (n = 9), who gave birth after 28 complete gestational weeks between 1 January 2001 and 31 December 2018. Univariable and multiple logistic regression analyses were carried out.

RESULTS

Maternal age >34 years (adjusted odds ratio 2.52; 95% confidence interval 1.25-5.07) and pre-pregnancy body mass index >24.9 kg/m2 (adjusted odds ratio 2.83, 95% confidence interval 1.47-5.46) were independent risk factors for GDM in women with DC twins. Newborns from women with GDM DC twins were more likely to be admitted to the neonatal intensive care unit (adjusted odds ratio 1.70, 95% confidence interval 1.06-2.72) than newborns from women with non-GDM DC twins. Other pregnancy and neonatal outcomes were similar between the two groups.

CONCLUSIONS

Advanced maternal age and pre-pregnancy overweight or obesity are risk factors for GDM in women with DC twins. Except for a nearly twofold increased risk of neonatal intensive care unit admission of newborns, the pregnancy and neonatal outcomes for women with GDM DC twins are similar to those for women with non-GDM DC twins.

Risk factors for abnormal postpartum glycemic states in women diagnosed with gestational diabetes by the International Association of Diabetes and Pregnancy Study Groups criteria

AIMS/INTRODUCTION

To evaluate the rate of postpartum glycemic screening tests (PGST) in women with gestational diabetes mellitus (GDM), and to investigate risk factors for abnormal PGST results.

MATERIALS AND METHODS

We retrospectively analyzed the obstetric data of 1,648 women with GDM who gave birth after 28 completed weeks of gestation between 1 July 2011 and 31 December 2019 at Taipei Chang Gung Memorial Hospital, Taiwan. GDM was diagnosed by the International Association of Diabetes and Pregnancy Study Groups criteria. PGST was carried out at 6-12 weeks postpartum with a 75-g, 2-h oral glucose tolerance test, and the results were classified into normal, prediabetes and diabetes mellitus. Multiple logistic regression was used to assess the associations between various risk factors and abnormal PGST results.

RESULTS

In total, 493 (29.9%) women underwent PGST and 162 (32.9%) had abnormal results, including 135 (27.4%) with prediabetes and 27 (5.5%) with diabetes mellitus. Significant risk factors for postpartum diabetes mellitus included insulin therapy during pregnancy (adjusted odds ratio [OR] 10.79, 95% confidence interval [CI] 4.07-28.58), birthweight >4,000 g (adjusted OR 10.22, 95% CI 1.74-59.89) and preterm birth <37 weeks' gestation (adjusted OR 3.33, 95% CI 1.09-10.22); whereas prepregnancy body mass index >24.9 kg/m2 (adjusted OR 1.99, 95% CI 1.24-3.21) was the major risk factor for postpartum prediabetes.

CONCLUSIONS

Less than one-third of women with GDM underwent PGST, and nearly one-third of these women had abnormal results. Future efforts should focus on reducing the barriers to PGST in women with GDM.

Effect of Hydrocortisone on Angiotensinogen (AGT) Mutation-Causing Autosomal Recessive Renal Tubular Dysgenesis

We has identified a founder homozygous E3_E4 del: 2870 bp deletion + 9 bp insertion in AGT gene encoding angiotensinogen responsible for autosomal recessive renal tubular dysgenesis (ARRTD) with nearly-fatal outcome. High-dose hydrocortisone therapy successfully rescued one patient with an increased serum Angiotensinogen (AGT), Ang I, and Ang II levels. The pathogenesis of ARRTD caused by this AGT mutation and the potential therapeutic effect of hydrocortisone were examined by in vitro functional studies. The expression of this truncated AGT protein was relatively low with a dose-dependent manner. This truncated mutation diminished the interaction between mutant AGT and renin. The truncated AGT also altered the glucocorticoid receptor (GR)-dependent transactivation, indicating that AGT may affect the development of proximal convoluted tubule by alteration of glucocorticoid-dependent transactivation. In hepatocytes, hydrocortisone increased the AGT level by accentuating the stability of mutant AGT and increasing its binding with renin. Therefore, hydrocortisone may exert the therapeutic effect through the enhanced stability and interaction with renin of truncated AGT in patients carrying this AGT mutation.

A novel de novo mutation in COL2A1 gene associated with fetal skeletal dysplasia

OBJECTIVE

Skeletal dysplasias, caused by genetic mutations, are a heterogenous group of heritable disorders affecting bone development during fetal life. Stickler syndrome, one of the skeletal dysplasias, is an autosomal dominant connective tissue disorder caused by abnormal collagen synthesis owing to a genetic mutation in COL2A1.

CASE REPORT

We present the case of a 38-year-old multipara woman whose first trimester screening showed a normal karyotype. However, the bilateral femur and humerus length symmetrically shortened after 20 weeks. Next-generation sequencing for mutations in potential genes leading to skeletal dysplasia detected a novel de novo mutation (c.1438G > A, p.Gly480Arg) in COL2A1, causing Stickler syndrome type 1. This pathogenic mutation might impair or destabilize the collagen structure, leading to collagen type II, IX, and XI dysfunction.

CONCLUSION

We identified a novel de novo mutation in COL2A1 related to the STL1 syndrome and delineated the extent of the skeletal dysplasia disease spectrum.

A Taiwan's experience: A case report and review of literature of successful early intrauterine treatment with radiofrequency ablation in twin reversed arterial perfusion (TRAP) sequence

Acardiac twin or twin reversed arterial perfusion (TRAP) sequence is a rare medical complication of Monozygotic twins. Taiwanese Obstetricians usually treat TRAP sequence conservatively. Occasionally, repeated amnio-reduction is performed to decompress the polyhydramnios caused by the TRAP sequence, even though there was no correction of the pathophysiologic mechanism. Radiofrequency ablation is a minimally invasive, percutaneous technique that can effectively obliterate blood supply to an acardiac twin to preserve and protect the pump twin. This recent technique has never been used before for the treatment of the TRAP sequence in Taiwan. This article reported the first-hand experience of acardiac twin management with RFA in Taipei Chang Gung Memorial Hospital.

Application of cattle placental stem cells for treating ovarian follicular cyst

BACKGROUND

High humidity and temperature in Taiwan have significant effects on the reproductivity of Holstein cattle, resulting in the occurrence of bovine ovarian follicular cyst (OFC). Because of economic loss from OFC, manual rupture and hormone injection have been advocated for the management of OFC. However, these incomplete treatments increase hormone resistance in cattle. Mesenchymal stem cells (MSCs) derived from placental stem cells (PSCs) demonstrate potential properties for the treatment of several diseases via promoting angiogenesis and immune modulation.

AIM

To establish the possibility of cattle placental stem cells (CPSCs) as a treatment modality for OFC of cows in Taiwan.

METHODS

The cows with OFC were divided into three groups: control (BC1 and BC2), hormone (H1 and H2), and CPSC (PS1 and PS2) treatment groups. In the hormone treatment group, the cows were given gonadotrophin-releasing hormone (GnRH)-prostaglandin-GnRH intramuscular injection with or without drainage of follicular fluid. In the CPSC treatment group, CPSCs were isolated from the placenta after labor. With the identification of surface antigen on stem cells, the cows were administered ovarian injection of 1 × 10⁶ or 6 × 10⁶ CPSCs with drainage. In all groups, OFC was scanned by ultrasound once a week for a total of seven times. The concentrations of estradiol and progesterone in serum were tested in the same period. The estrus cycle was analyzed by food intake and activity. If estrus was detected, artificial insemination was conducted. Then the cow was monitored by ultrasound for confirmation of pregnancy.

RESULTS

After 7 d of culture, CPSCs were successfully isolated from placental pieces. CPSCs significantly proliferated every 24 h and had high expression of MSC markers such as cluster of differentiation 44, as determined by flow cytometry. Ultrasound showed lower numbers of OFCs with drainage of follicular fluid. We achieved recovery rates of 0%, 50%, 50%, 75%, 75% and 75% in BC1, BC2, H1, H2, PS1, and PS2, respectively. Higher concentrations of progesterone were detected in the CPSC treatment groups. However, both hormone and CPSC treatment groups had no significant difference in the concentration of estradiol. The estrus rate was 0%, 100%, 25%, 75%, 75% and 75% in BC1, BC2, H1, H2, PS1, and PS2, respectively. The two fetuses were born in H2 and PS1. In brief, cows with CPSC injection achieved higher recovery, estrus, and inseminated conception rates.

CONCLUSION

CPSCs have efficacy in treating cows with OFC, and thus, may serve as an alternative treatment for reproductive disorders.

Current update of first trimester preeclampsia screening in Asia

In consideration of high prevalence of preeclampsia, enormous studies attempted to look for strategies in early gestation. Hence, a powerful screening should be built up in first trimester. Then, Aspirin could be administrated for proper prevention. The objective of this article is reviewing the screening for preeclampsia in first trimester recently. To identify the high-risk group precisely, an effective model should be recommended to Asian population. Articles related to first trimester screening of PE in Asia from databases of PubMed, ScienceDirect and Scopus were searched for this narrative review. The criteria included randomized clinical trials, observational prospective and retrospective cohort studies, case-control studies, systematic review and meta-analysis and professional review articles. Screening models combining maternal factors, biophysical factors, ultrasound studies and biochemical factors achieved high predictive performance of preeclampsia. In Asia, the detection rate of the Fetal Medicine Foundation is superior to those of the American College of Obstetricians and Gynecologists and the National Institute for Health and Care Excellence. Consequently, this effective model from the Fetal Medicine Foundation should be continuously used for screening in first trimester for the Asian.

Autosomal Recessive Renal Tubular Dysgenesis Caused by a Founder Mutation of Angiotensinogen

Introduction

Autosomal recessive renal tubular dysgenesis (ARRTD) caused by inactivation mutations in AGT, REN, ACE, and AGTR is a very rare but fatal disorder with an unknown prevalence.

Methods

We report 6 Taiwanese individuals with ARRTD from 6 unrelated families diagnosed by renal histology. Clinical features, outcome, and prevalence of carrier heterozygosity were examined.

Results

All patients exhibited antenatal oligohydramnios, postnatal anuria, pulmonary hypoplasia, and profound hypotension refractory to interventions. Angiotensinogen (AGT) protein levels were diminished in the liver, along with reduced serum AGT, angiotensin I (Ang I) and angiotensin II (Ang II) levels. Neonatal demise occurred in all but 1 case. All individuals carried the same homozygous E3_E4 del:2870bp deletion+9bp insertion in AGT, which led to a truncated protein (1-292 amino acid). The allelic frequency of this heterozygous AGT mutation was approximately 1.2% (6/500), suggesting that ARRTD may not be exceedingly rare in Taiwan. This mutation results in skipping of exons encoding the serpin domain of AGT, which is important for renin interaction and the generation of truncated protein. In silico modeling revealed a diminished interaction between mutant AGT and renin. One patient survived after responding to high-dose hydrocortisone therapy, with resolution of profound hypotension, accompanied by an increase in serum AGT, Ang I, and Ang II levels.

Conclusion

This AGT mutation may lead to the diminished interaction with renin and decreased Ang I and Ang II generation. Hydrocortisone may potentially rescue cases of ARRTD caused by this truncated AGT.

First-trimester pre-eclampsia biomarker profiles in Asian population: multicenter cohort study

OBJECTIVES

To (i) evaluate the applicability of the European-derived biomarker multiples of the median (MoM) formulae for risk assessment of preterm pre-eclampsia (PE) in seven Asian populations, spanning the east, southeast and south regions of the continent, (ii) perform quality-assurance (QA) assessment of the biomarker measurements and (iii) establish criteria for prospective ongoing QA assessment of biomarker measurements.

METHODS

This was a prospective, non-intervention, multicenter study in 4023 singleton pregnancies, at 11 to 13 + 6 weeks' gestation, in 11 recruiting centers in China, Hong Kong, India, Japan, Singapore, Taiwan and Thailand. Women were screened for preterm PE between December 2016 and June 2018 and gave written informed consent to participate in the study. Maternal and pregnancy characteristics were recorded and mean arterial pressure (MAP), mean uterine artery pulsatility index (UtA-PI) and maternal serum placental growth factor (PlGF) were measured in accordance with The Fetal Medicine Foundation (FMF) standardized measurement protocols. MAP, UtA-PI and PlGF were transformed into MoMs using the published FMF formulae, derived from a largely Caucasian population in Europe, which adjust for gestational age and covariates that affect directly the biomarker levels. Variations in biomarker MoM values and their dispersion (SD) and cumulative sum tests over time were evaluated in order to identify systematic deviations in biomarker measurements from the expected distributions.

RESULTS

In the total screened population, the median (95% CI) MoM values of MAP, UtA-PI and PlGF were 0.961 (0.956-0.965), 1.018 (0.996-1.030) and 0.891 (0.861-0.909), respectively. Women in this largely Asian cohort had approximately 4% and 11% lower MAP and PlGF MoM levels, respectively, compared with those expected from normal median formulae, based on a largely Caucasian population, whilst UtA-PI MoM values were similar. UtA-PI and PlGF MoMs were beyond the 0.4 to 2.5 MoM range (truncation limits) in 16 (0.4%) and 256 (6.4%) pregnancies, respectively. QA assessment tools indicated that women in all centers had consistently lower MAP MoM values than expected, but were within 10% of the expected value. UtA-PI MoM values were within 10% of the expected value at all sites except one. Most PlGF MoM values were systematically 10% lower than the expected value, except for those derived from a South Asian population, which were 37% higher.

CONCLUSIONS

Owing to the anthropometric differences in Asian compared with Caucasian women, significant differences in biomarker MoM values for PE screening, particularly MAP and PlGF MoMs, were noted in Asian populations compared with the expected values based on European-derived formulae. If reliable and consistent patient-specific risks for preterm PE are to be reported, adjustment for additional factors or development of Asian-specific formulae for the calculation of biomarker MoMs is required. We have also demonstrated the importance and need for regular quality assessment of biomarker values. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Therapeutic effects of conditioned - DPBS from amniotic stem cells on lactating cow mastitis

OBJECTIVE

Bovine mastitis results in economic loss due to decrease in milk production. Antibiotic ointments are commonly used for treating. However, residue and anti-microbial resistance warranted attention progressively. Fortunately, stem cell anti-inflammatory properties and paracrine expression of cytokines accelerates wound healing and suppresses inflammatory reactions in mastitis. The objective of this study is to use the conditioned-Dulbecco's pluripotent stem cells (DPBS) from amniotic membrane stem cells (AMSCs) in treating bovine mastitis.

MATERIALS AND METHODS

The cows with mastitis were divided into two groups. In antibiotic control group, the cows were given tetraneomycin ointment. In conditioned-DPBS of AMSCs treatment group, amniotic membrane was collected for AMSCs after delivery. With expression of surface antigen and potential of tri-linage differentiation, AMSCs were injected into mammary glands. Then, milk was sampled every three days to monitor the effect of both treatments. The quality of milk was measured with pH, titratable acidity, free calcium ions and somatic cell count.

RESULTS

Our results demonstrated the Bovine AMSCs expressed CD44, low levels of CD4 and no CD105. Bovine AMSCs demonstrated the differentiation capability in the tri-cell lineages. Mastitis treatment with conditioned-DPBS from AMSCs (experimental group) and conventional antibiotics (control group) showed insignificant difference in pH value and titratable acidity. The level of ionic calcium concentration in the conditioned-DPBS group decreased from 3rd day to 12th day, while the level in the antibiotic group decreased from 0 day to 12th day. The somatic cell number was similar in both groups, which meet the standard of Taiwan milk collection.

CONCLUSION

In conclusion, conditioned-DPBS from bovine AMSCs has the therapeutic potential to treat bovine mastitis and may replace antibiotics therapy in the future.

Association between maternal anemia at admission for delivery and adverse perinatal outcomes

BACKGROUND

Maternal anemia is a risk factor for poor pregnancy outcomes and threatens maternal or fetal life. Anemia increases the risk of low birth weight and preterm birth. We aimed to determine the cutoff level of hemoglobin and risk factors for maternal anemia at admission for delivery and investigate the association between maternal anemia and adverse perinatal outcomes in contemporary Taiwanese women.

METHODS

About 32,234 women admitted to the Taipei Chang Gung Memorial Hospital from 2001 to 2016 were enrolled in this retrospective observational cohort study. The prevalence of pre-delivery maternal anemia in Taiwan and the maternal demographic and perinatal outcomes associated with maternal anemia was assessed.

RESULTS

The 10th and 5th percentile hemoglobin levels of the test cohort (2001-2008, n = 15,602) were 10.8 g/dL and 9.9 g/dL, respectively. In the study cohort (2009-2016, n = 13,026), women who were multiparous, who were aged >34 years, with history of cesarean delivery, and with history of uterine fibroids had higher prevalence of anemia. Anemic women were at increased risk of cesarean delivery, primary cesarean delivery, premature rupture of membranes, early preterm birth <34 weeks, having very low birth weight infants (<1,500 g), having large for gestational age infants, and neonatal intensive care center transfer, but at lower risk of having small for gestational age infants.

CONCLUSION

Maternal anemia at delivery is a risk factor for primary cesarean delivery and adverse maternal and neonatal outcomes. Furthermore, we hypothesize that maternal anemia might increase fetoplacental vasculogenesis and angiogenesis as an adaptive response.

Prospective evaluation of screening performance of first-trimester prediction models for preterm preeclampsia in an Asian population

BACKGROUND

The administration of aspirin <16 weeks gestation to women who are at high risk for preeclampsia has been shown to reduce the rate of preterm preeclampsia by 65%. The traditional approach to identify such women who are at risk is based on risk factors from maternal characteristics, obstetrics, and medical history as recommended by the American College of Obstetricians and Gynecologists and the National Institute for Health and Care Excellence. An alternative approach to screening for preeclampsia has been developed by the Fetal Medicine Foundation. This approach allows the estimation of patient-specific risks of preeclampsia that requires delivery before a specified gestational age with the use of Bayes theorem-based model.

OBJECTIVE

The purpose of this study was to examine the diagnostic accuracy of the Fetal Medicine Foundation Bayes theorem-based model, the American College of Obstetricians and Gynecologists, and the National Institute for Health and Care Excellence recommendations for the prediction of preterm preeclampsia at 11-13⁺⁶ weeks gestation in a large Asian population STUDY DESIGN: This was a prospective, nonintervention, multicenter study in 10,935 singleton pregnancies at 11-13⁺⁶ weeks gestation in 11 recruiting centers across 7 regions in Asia between December 2016 and June 2018. Maternal characteristics and medical, obstetric, and drug history were recorded. Mean arterial pressure and uterine artery pulsatility indices were measured according to standardized protocols. Maternal serum placental growth factor concentrations were measured by automated analyzers. The measured values of mean arterial pressure, uterine artery pulsatility index, and placental growth factor were converted into multiples of the median. The Fetal Medicine Foundation Bayes theorem-based model was used for the calculation of patient-specific risk of preeclampsia at <37 weeks gestation (preterm preeclampsia) and at any gestation (all preeclampsia) in each participant. The performance of screening for preterm preeclampsia and all preeclampsia by a combination of maternal factors, mean arterial pressure, uterine artery pulsatility index, and placental growth factor (triple test) was evaluated with the adjustment of aspirin use. We examined the predictive performance of the model by the use of receiver operating characteristic curve and calibration by measurements of calibration slope and calibration in the large. The detection rate of screening by the Fetal Medicine Foundation Bayes theorem-based model was compared with the model that was derived from the application of American College of Obstetricians and Gynecologists and National Institute for Health and Care Excellence recommendations.

RESULTS

There were 224 women (2.05%) who experienced preeclampsia, which included 73 cases (0.67%) of preterm preeclampsia. In pregnancies with preterm preeclampsia, the mean multiples of the median values of mean arterial pressure and uterine artery pulsatility index were significantly higher (mean arterial pressure, 1.099 vs 1.008 [P<.001]; uterine artery pulsatility index, 1.188 vs 1.063[P=.006]), and the mean placental growth factor multiples of the median was significantly lower (0.760 vs 1.100 [P<.001]) than in women without preeclampsia. The Fetal Medicine Foundation triple test achieved detection rates of 48.2%, 64.0%, 71.8%, and 75.8% at 5%, 10%, 15%, and 20% fixed false-positive rates, respectively, for the prediction of preterm preeclampsia. These were comparable with those of previously published data from the Fetal Medicine Foundation study. Screening that used the American College of Obstetricians and Gynecologists recommendations achieved detection rate of 54.6% at 20.4% false-positive rate. The detection rate with the use of National Institute for Health and Care Excellence guideline was 26.3% at 5.5% false-positive rate.

CONCLUSION

Based on a large number of women, this study has demonstrated that the Fetal Medicine Foundation Bayes theorem-based model is effective in the prediction of preterm preeclampsia in an Asian population and that this method of screening is superior to the approach recommended by American College of Obstetricians and Gynecologists and the National Institute for Health and Care Excellence. We have also shown that the Fetal Medicine Foundation prediction model can be implemented as part of routine prenatal care through the use of the existing infrastructure of routine prenatal care.

Bifurcation Generated Mechanical Frequency Comb

We demonstrate a novel response of a nonlinear micromechanical resonator when operated in a region of strong, nonlinear mode coupling. The system is excited with a single drive signal and its response is characterized by periodic amplitude modulations that occur at timescales based on system parameters. The periodic amplitude modulations of the resonator are a consequence of nonlinear mode coupling and are responsible for the emergence of a "frequency-comb" regime in the spectral response. By considering a generic model for a 1∶3 internal resonance, we demonstrate that the novel behavior results from a saddle node on an invariant circle (SNIC) bifurcation. The ability to control the operating parameters of the micromechanical structures reported here makes the simple micromechanical resonator an ideal test bed to study the dynamic response of SNIC behavior demonstrated in mechanical, optical, and biological systems.

Long-Term Hematopoietic Engraftment of Congenic Amniotic Fluid Stem Cells After in Utero Intraperitoneal Transplantation to Immune Competent Mice

Clinical success of in utero transplantation (IUT) using allogeneic hematopoietic stem cells (HSCs) has been limited to fetuses that lack an immune response to allogeneic cells due to severe immunological defects, and where transplanted genetically normal cells have a proliferative or survival advantage. Amniotic fluid (AF) is an autologous source of stem cells with hematopoietic potential that could be used to treat congenital blood disorders. We compared the ability of congenic and allogeneic mouse AF stem cells (AFSC) to engraft the hematopoietic system of time-mated C57BL/6J mice (E13.5). At 4 and 16 weeks of age, multilineage donor engraftment was higher in congenic versus allogeneic animals. In vitro mixed lymphocyte reaction confirmed an immune response in the allogeneic group with higher CD4 and CD8 cell counts and increased proliferation of stimulated lymphocytes. IUT with congenic cells resulted in 100% of donor animals having chimerism of around 8% and successful hematopoietic long-term engraftment in immune-competent mice when compared with IUT with allogeneic cells. AFSCs may be useful for autologous cell/gene therapy approaches in fetuses diagnosed with congenital hematopoietic disorders.

Structural optimization for nonlinear dynamic response

Much is known about the nonlinear resonant response of mechanical systems, but methods for the systematic design of structures that optimize aspects of these responses have received little attention. Progress in this area is particularly important in the area of micro-systems, where nonlinear resonant behaviour is being used for a variety of applications in sensing and signal conditioning. In this work, we describe a computational method that provides a systematic means for manipulating and optimizing features of nonlinear resonant responses of mechanical structures that are described by a single vibrating mode, or by a pair of internally resonant modes. The approach combines techniques from nonlinear dynamics, computational mechanics and optimization, and it allows one to relate the geometric and material properties of structural elements to terms in the normal form for a given resonance condition, thereby providing a means for tailoring its nonlinear response. The method is applied to the fundamental nonlinear resonance of a clamped-clamped beam and to the coupled mode response of a frame structure, and the results show that one can modify essential normal form coefficients by an order of magnitude by relatively simple changes in the shape of these elements. We expect the proposed approach, and its extensions, to be useful for the design of systems used for fundamental studies of nonlinear behaviour as well as for the development of commercial devices that exploit nonlinear behaviour.

Trisomy 21 mid-trimester amniotic fluid induced pluripotent stem cells maintain genetic signatures during reprogramming: implications for disease modeling and cryobanking

Trisomy 21 is the most common chromosomal abnormality and is associated primarily with cardiovascular, hematological, and neurological complications. A robust patient-derived cellular model is necessary to investigate the pathophysiology of the syndrome because current animal models are limited and access to tissues from affected individuals is ethically challenging. We aimed to derive induced pluripotent stem cells (iPSCs) from trisomy 21 human mid-trimester amniotic fluid stem cells (AFSCs) and describe their hematopoietic and neurological characteristics. Human AFSCs collected from women undergoing prenatal diagnosis were selected for c-KIT(+) and transduced with a Cre-lox-inducible polycistronic lentiviral vector encoding SOX2, OCT4, KLF-4, and c-MYC (50,000 cells at a multiplicity of infection (MOI) 1-5 for 72 h). The embryonic stem cell (ESC)-like properties of the AFSC-derived iPSCs were established in vitro by embryoid body formation and in vivo by teratoma formation in RAG2(-/-), γ-chain(-/-), C2(-/-) immunodeficient mice. Reprogrammed cells retained their cytogenetic signatures and differentiated into specialized hematopoietic and neural precursors detected by morphological assessment, immunostaining, and RT-PCR. Additionally, the iPSCs expressed all pluripotency markers upon multiple rounds of freeze-thawing. These findings are important in establishing a patient-specific cellular platform of trisomy 21 to study the pathophysiology of the aneuploidy and for future drug discovery.

Escape statistics for parameter sweeps through bifurcations

We consider the dynamics of systems undergoing parameter sweeps through bifurcation points in the presence of noise. Of interest here are local codimension-one bifurcations that result in large excursions away from an operating point that is transitioning from stable to unstable during the sweep, since information about these "escape events" can be used for system identification, sensing, and other applications. The analysis is based on stochastic normal forms for the dynamic saddle-node and subcritical pitchfork bifurcations with a time-varying bifurcation parameter and additive noise. The results include formulation and numerical solution for the distribution of escape events in the general case and analytical approximations for delayed bifurcations for which escape occurs well beyond the corresponding quasistatic bifurcation points. These bifurcations result in amplitude jumps encountered during parameter sweeps and are particularly relevant to nano- and microelectromechanical systems, for which noise can play a significant role.

Spectrum of an oscillator with jumping frequency and the interference of partial susceptibilities

We study an underdamped oscillator with random frequency jumps. We describe the oscillator spectrum in terms of coupled susceptibilities for different-frequency states. Depending on the parameters, the spectrum has a fine structure or displays a single asymmetric peak. For nanomechanical resonators with a fluctuating number of attached molecules, it is found in a simple analytical form. The results bear on dephasing in various types of systems with jumping frequency.

Catastrophic sliding bifurcations and onset of oscillations in a superconducting resonator

This paper presents a general analysis and a concrete example of the catastrophic case of a discontinuity-induced bifurcation in so-called Filippov nonsmooth dynamical systems. Such systems are characterized by discontinuous jumps in the right-hand sides of differential equations across a phase space boundary and are often used as physical models of stick-slip motion and relay control. Sliding bifurcations of periodic orbits have recently been shown to underlie the onset of complex dynamics including chaos. In contrast to previously analyzed cases, in this work a periodic orbit is assumed to graze the boundary of a repelling sliding region, resulting in its abrupt destruction without any precursive change in its stability or period. Necessary conditions for the occurrence of such catastrophic grazing-sliding bifurcations are derived. The analysis is illustrated in a piecewise-smooth model of a stripline resonator, where it can account for the abrupt onset of self-modulating current fluctuations. The resonator device is based around a ring of NbN containing a microbridge bottleneck, whose switching between normal and super conducting states can be modeled as discontinuous, and whose fast temperature versus slow current fluctuations are modeled by a slow-fast timescale separation in the dynamics. By approximating the slow component as Filippov sliding, explicit conditions are derived for catastrophic grazing-sliding bifurcations, which can be traced out as parameters vary. The results are shown to agree well with simulations of the slow-fast model and to offer a simple explanation of one of the key features of this experimental device.

Reliability and reproducibility of vertical diffusion cells for determining release rates from semisolid dosage forms

PURPOSE

USP has formed Advisory Panels to ensure the integrity of laboratory procedures for non-oral routes of administration and expects that the panels will recommend performance tests (performance qualification, PQ) for these dosage forms as well as performance verification tests (PVT) for those PQ tests. An integral part of PQ is PVT, in which a standard formulation is first tested in a metrologically sound collaborative study to set acceptance criteria. Individual laboratories can then test the performance of their product by comparing their results to those obtained from the USP collaborative study. These studies are guided by metrological principles, e.g., those of the International Organization for Standardization (ISO) 43-1, which succinctly states that "one of the main uses of proficiency testing schemes is to assess laboratories' ability to perform tests competently."

MATERIALS AND METHODS

Four laboratories conducted two collaborative studies to determine the reliability and reproducibility--understood in metrological terms--of release rates from semisolid dosage forms using the vertical diffusion cell (VDC).

RESULTS

The experiments reported here from the second study found that the major contributor to variability is the interlaboratory component that may include intermediate precision considerations other than analyst. Because all laboratories used the same model equipment, one might expect that the observed reproducibility CV was lower than if the laboratories used different models or equipment made by different manufacturers. Also, more variability was observed with the creams than the other dosage forms.

CONCLUSIONS

The results from the preliminary collaborative study found inconsistency among the laboratories. After operator training, the results from the second study were more consistent, suggesting the initial results were associated with variations among the laboratories in performing the methods and procedures and conducting the protocols. Those results emphasize that although the in vitro release procedure is simple and reproducible, training is needed. The data presented suggest that testing of in vitro release by VDCs should be considered as a PVT for topical semisolid dosage forms. Thus, a standard semisolid product is needed, along with a means for setting acceptance criteria. The SUPAC-SS Guidance may be helpful in the latter regard.

Maternal anxiety about prenatal screening for group B streptococcus disease and impact of positive colonization results

OBJECTIVE

Universal screening for colonization by group B streptococcus (GBS) is the recommended strategy to reduce incidence of colonization in newborns and prevent neonatal GBS-related disease. This study was designed to assess maternal anxiety levels about prenatal screening and psychological impact of positive colonization test results.

METHODS

A total of 71 women who screened positively for GBS colonization and 112 screen-negative women (controls) were recruited. Anxiety levels were measured by the Spielberger State Trait-anxiety Inventory just before the GBS screening test, 1-week after testing, and 1-week after delivery. After delivery of their infants, all participants were asked to respond with a Likert scale line about attitudes toward being tested for GBS colonization.

RESULTS

Women with GBS colonization reported significantly greater psychological distress on state-anxiety scores after the full report was received. The trait- and state-anxiety scores before GBS screen testing and after delivery did not differ between the groups. Both groups of women were strongly positive about being screened for GBS in the current pregnancy and in future pregnancies.

CONCLUSION

Women with GBS colonization did not have a sustained increase in anxiety; therefore, clinician concerns about causing maternal anxiety should not be an impediment to test for GBS.

Metabolic changes during glucose tolerance tests in migraine attacks

(1) Intravenous glucose tolerance tests have been carried out on 6 migraine sufferers on two occasions. The first study was carried out during a migraine attack and the second was performed in an attack-free period. The patients had fasted overnight and the investigations were carried out in the morning. Samples of venous blood were taken for measurement of concentrations of glucose, lactate, pyruvate, free fatty acids (FFA), glycerol, ketone-bodies, insulin and growth hormone. (2) an impaired tolerance to glucose was found during the migraine attacks compared with the control studies. Elevated ketone and FFA levels were found during the attacks and may have accounted for the glucose intolerance. The elevation of plasma FFA levels during the migraine attacks paralleled changes in blood glycerol concentrations suggesting increased lipolysis during the attacks. Growth hormone and cortisol were raised and insulin was depressed during attacks. (3) Our observations, in which the patients acted as their own controls, imply increased lipolysis during migraine attacks and are in contrast to previously reported studies. The patterns of metabolic and hormonal changes are consistent with a stress response during the attacks and the significance in relation to the causation of the attacks is discussed.