Preeclamptic serum and soluble fms-like tyrosine kinase-1 suppress endothelial inward rectifier potassium currents

INTRODUCTION

Inward rectifier K+ (Kir) channel, a major factor determining endothelial membrane potential, regulates Ca2+ influx and vasodilator release, which is impaired in preeclamptic blood vessels. Previously, human umbilical vein endothelial cell (HUVEC) Kir currents were shown to decrease after incubating in preeclamptic plasma. We aimed to demonstrate whether sFlt-1, which is high in preeclamptic blood, could inhibit Kir channel function and expression.

METHODS

HUVECs were cultured in regular medium, regular medium with added sFlt-1, or serum from preeclampsia patients or normal pregnant women (Control, sFlt-1, PE, or NP, respectively). Using whole-cell patch clamp technique, we identified Kir currents with the Kir blocker 2 mM BaCl2 and compared the currents among groups. The expression of Kir 2.1 and 2.2 channels were determined using immunofluorescent staining.

RESULTS

sFlt-1 and PE groups exhibited similar Kir currents, while NP group possessed significantly larger currents, similar to Control group currents. Moreover, sFlt-1 and sFlt-1/PlGF ratio showed strong negative correlation with Kir currents (r = -0.71 and -0.70, respectively; P < 0.05). There were no significant differences in mean fluorescence intensity representing Kir 2.1 and 2.2 channels expression in all four groups.

DISCUSSION

This is the first report to demonstrate sFlt-1 inhibition against Kir currents, which could lead to maternal endothelial dysfunction and hypertension seen in preeclampsia. However, channel expression was unaffected by sFlt-1 incubation, suggesting dysfunctions of channel or other processes (e.g., membrane translocation). The present data could pave the way for novel therapies targeting sFlt-1 or Kir to alleviate hypertension in preeclampsia.

Pharmacogenomics of Preeclampsia therapies: Current evidence and future challenges for clinical implementation

Preeclampsia is a pregnancy-specific disorder, and it is a leading cause of maternal and perinatal morbidity and mortality. The application of pharmacogenetics to antihypertensive agents and dose selection in women with preeclampsia is still in its infancy. No current prescribing guidelines from the clinical pharmacogenetics implementation consortium (CPIC) exist for preeclampsia. Although more studies on pharmacogenomics are underway, there is some evidence for the pharmacogenomics of preeclampsia therapies, considering both the pharmacokinetic (PK) and pharmacodynamic (PD) properties of drugs used in preeclampsia. It has been revealed that the CYP2D6*10 variant is significantly higher in women with preeclampsia who are non-responsive to labetalol compared to those who are in the responsive group. Various genetic variants of PD targets, i.e., NOS3, MMP9, MMP2, TIMP1, TIMP3, VEGF, and NAMPT, have been investigated to assess the responsiveness of antihypertensive therapies in preeclampsia management, and they indicated that certain genetic variants of MMP9, TIMP1, and NAMPT are more frequently observed in those who are non-responsive to anti-hypertensive therapies compared to those who are responsive. Further, gene-gene interactions have revealed that NAMPT, TIMP1, and MMP2 genotypes are associated with an increased risk of preeclampsia, and they are more frequently observed in the non-responsive subgroup of women with preeclampsia. The current evidence is not rigorous enough for clinical implementation; however, an institutional or regional-based retrospective analysis of audited data may help close the knowledge gap during the transitional period from a traditional approach (a "one-size-fits-all" strategy) to the pharmacogenomics of preeclampsia therapies.

A conditional standard for the customized fetal growth trajectory in twin pregnancy

BACKGROUND

The difference in the birth weights between twins and singletons grows with advancing gestation. Although many fetal weight standards based on ultrasonographic measurements have been created for tracking fetal growth in twin pregnancies, their applicability to other groups is limited by the fact that they are population specific.

OBJECTIVE

This study aimed to generate conditional centiles for growth assessment of twin fetuses and to compare them with other population-based growth standards for singleton and twin fetuses.

STUDY DESIGN

This was a retrospective, longitudinal study of ultrasound-based estimated fetal weight data of normal twin fetuses delivered after 34 weeks of gestation. Linear mixed effects models that adjusted for maternal characteristics, fetal gender, and chorionicity were used to evaluate the relationship between estimated fetal weight and gestational age. The estimated fetal weight reference values were calculated using conditional centile based on the estimated fetal weight at an earlier gestational age. To compare our results with previous studies, fetal growth curves were generated using a formula we created that included maternal characteristics and the estimated fetal weight at 24 weeks of gestation in these studies. In a subgroup analysis of our low-risk twin babies born at full term, we calculated the number of fetuses who were reclassified as being in the bottom 10th percentile using each of the previous population-based standard.

RESULTS

A total of 2644 ultrasounds with a median of 4 scans per fetus from 572 twin pregnancies were included in this analysis. In the cohort, 36% of the fetuses were monochorionic. Maternal age, body mass index, and the interaction between fetal gender and chorionicity were significantly associated with estimated fetal weight. The predicted growth curves matched the growth standard for twins. In our low-risk group, when the singleton standard was used, the incidence of estimated fetal weight <10th percentile was above 20% from gestational week 24 to 38, and this incidence varied when reclassified using other population-based twin standards.

CONCLUSION

This conditional growth chart was specifically designed to assess fetal growth in twin pregnancies, but it is generalizable to other populations.

Mentoring a surgical team towards procedural competence in the early learning curve for selective fetoscopic laser photocoagulation

INTRODUCTION

Selective fetoscopic laser photocoagulation (SFLP) for twin-to-twin transfusion syndrome (TTTS) is challenging for new surgeons at the start of their learning curve. We described an approach utilising telementoring and team-based training to facilitate rapid attainment of the skills required for safe and efficient practice with a limited caseload.

METHODS

We conducted a prospective observational study of SFLP performed by the novice primary surgical team in three stages: under direct on-site supervision from an expert mentor (Group 1), with remote tele-guidance from that mentor (Group 2) and independently (Group 3), at an academic tertiary hospital in Singapore. The primary team undertook regular training on high-fidelity tissue models to accelerate skills acquisition and complement the surgical performance.

RESULTS

9 patients diagnosed with Stage 2 TTTS were assessed for procedural characteristics, surgical outcomes and perinatal survival following SFLP. There were no significant differences in operative duration, anastomoses ablated, gestational age or birth weight at delivery. The complications observed were: recurrent TTTS (22.2% of pregnancies), twin anaemia polycythaemia sequence (33.3%), preterm prelabour membrane rupture (22.2%) and delivery at < 32 weeks (44.4%). ≥ 1 twin was live-born in 88.9% of cases, while postnatal survival to six months of ≥ 1 twin occurred in 77.8% of cases.

CONCLUSION

Systematic mentoring and specialised skills training are useful in aiding new surgeons to negotiate the steep learning curve and achieve good outcomes at the start of a new practice, particularly in the setting of low patient numbers. This is best paired with dedicated model training to achieve and maintain surgical dexterity for this complex procedure.

Ablative effect of the interstitial laser setting in the human placental model

AIM

To assess the impact of laser power and time on interstitial ablation generated by neodymium-doped yttrium aluminium garnet (Nd:YAG) and diode laser in the human placental model.

METHODS

The experiment was carried out in a simulation model of interstitial laser ablation on ex-vivo placental tissue. One-hundred and forty-four pieces of fresh placentae were interstitially ablated with Nd:YAG or diode laser at various power (15, 20, 25, 30 W)-time (5, 10, 15 s) combinations. The ablation tissues were evaluated using both sonographic and histopathologic measurements.

RESULTS

Laser generator, power, and time significantly affected the ablation size (p < 0.001). The coagulation zone continuously increased with extending time at the power of 15, 20, and 25 W. When adjusting to the power of 30 W, increased time from 10 to 15 s did not induce the larger coagulation diameter. The maximal diameter was obtained at the laser power of 20 W for 15 s. The ablation from the diode laser was greater than that from Nd:YAG laser. The sonographic evaluation overestimated the ablation size by an average of 24%.

CONCLUSION

Diode laser destroys greater tissue than Nd:YAG laser. Different power settings of interstitial laser ablation produce diverse patterns of correlation between laser time and coagulation size.

Prospective Evaluation of International Prediction of Pregnancy Complications Collaborative Network Models for Prediction of Preeclampsia: Role of Serum sFlt-1 at 11-13 Weeks' Gestation

The study aimed to investigate whether serum sFlt-1 (soluble fms-like tyrosine kinase-1) at 11-13 weeks' gestation in pregnancies that subsequently developed preeclampsia was different from those without preeclampsia and compare screening performance of the International Prediction of Pregnancy Complications (IPPIC) reported models, which include various combinations of maternal factors, systolic blood pressure, diastolic blood pressure, PlGF (placental growth factor) and sFlt-1 and the competing risk (CR) models, which include various combinations of maternal factors, mean arterial pressure (MAP) and PlGF for predicting any-onset, early-onset, and late-onset preeclampsia. This was a prospective multicenter study in 7877 singleton pregnancies. The differences of the predictive performance between the IPPIC and CR models were compared. There were 141 women (1.79%) who developed preeclampsia, including 13 cases (0.17%) of early-onset preeclampsia and 128 cases (1.62%) of late-onset preeclampsia. In pregnancies that developed preeclampsia compared to unaffected pregnancies, median serum sFlt-1 levels and its MoMs were not significantly different (p>0.05). There was no significant association between gestational age at delivery and log₁₀ sFlt-1 and log₁₀ sFlt-1 MoM (p>0.05). The areas under the curve of CR models were significantly higher than the IPPIC models for the prediction of any-onset and late-onset preeclampsia but not for early-onset preeclampsia. In conclusion, there are no significant differences in the maternal serum sFlt-1 levels at 11-131 weeks' gestation between women who subsequently develop preeclampsia and those who do not. Moreover, the CR models for the prediction of any-onset and late-onset preeclampsia perform better than the IPPIC reported model.

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.

Teaching and training the total percutaneous fetoscopic myelomeningocele repair

Skin-over-biocellulose for Antenatal Fetoscopic Repair (SAFER) is a recently developed technique for fully percutaneous fetoscopic repair of myelomeningocele. The formation of a neo-dura mater triggered by the use of a biocellulose patch over the placode obviates the need of primary repair of fetal dura mater, and seems to further improve neurodevelopmental outcome. Insufflation of humidified carbon dioxide into the amniotic cavity requires proper training and a different equipment set from those used in the classic "under-water" fetoscopy. To shorten the learning curve of novice teams, we have developed a structured training course encompassing three critical steps: (1) visiting the proctor center, (2) selection of the first case, and (3) on-site training of the surgical team. Upon the site arrival, there will be: (1) theoretical lecture for all specialists involved in the fetal care, (2) simulation training, and (3) surgical proctoring. Proctor team can take over the surgery if the local team cannot complete. This training course has been successfully used in five different countries: Israel, Chile, Italy, USA and England and all local teams are already performing surgeries solo without any failures or maternal morbidity. Teaching new procedures in fetal medicine is challenging, because of the small number of candidate cases, and the direct relation of good outcomes and the number of cases operated. This proposed training modules may be adopted by other teams that want to embark on this type of novel minimally invasive treatment.

Minimizing cross transmission of SARS-CoV-2 in obstetric ultrasound during COVID-19 pandemic

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-associated infection (COVID-19) is affecting populations worldwide. This statement may serve as guidance for infection prevention and safe ultrasound practices during the COVID-19 pandemic. Ultrasound examination is a fundamental part of obstetric care, yet it is a potential vector for transmission of SARS-CoV-2. Decontamination methods should always be implemented for ultrasound equipment, especially in the presence of suspected or confirmed COVID-19 cases. There must be workflow policies to protect pregnant women and healthcare providers from nosocomial cross transmission of SARS-CoV-2. Cleaning and disinfecting of equipment must be in accordance with their potential of pathogen transmission. Consider using telemedicine and genetic technologies as an adjunctive of obstetric ultrasound to reduce patient crowding. Patient triage and education of healthcare providers of infection prevention are crucial to minimize cross contamination of SARS-CoV-2 during obstetric ultrasound.

Clinical Experiences of Intravenous Hydralazine and Labetalol for Acute Treatment of Severe Hypertension in Pregnant Thai Women

Response to acute treatment of severe hypertension during pregnancy in Asian women was not known. Labor and delivery checklists of Thai women treated with intravenous hydralazine or labetalol for systolic blood pressure (SBP) ≥ 160 or diastolic blood pressure (DBP) ≥ 110 mm Hg from January 2011 to December 2013 were reviewed as parts of an audit. Primary outcome was prompt achievement of SBP 140-150 and DBP 90-100 mm Hg after the first bolus. Secondary outcomes were medication-related undesired effects. The mean ± standard deviation age and prevalence of chronic hypertension in hydralazine (n = 62) versus labetalol (n = 64) groups were 32.5 ± 6 versus 29.9 ± 6.8 years and 50% versus 21.9%, respectively (P < .05). Magnesium sulfate was promptly administered on admission to every woman to prevent seizure. Targeted blood pressure was timely achieved in 41.9% and 67.2% of the hydralazine and labetalol groups, respectively (P < .05). Nonreassuring fetal heart rate occurred in 51.6% and 32.8% of the hydralazine and labetalol groups, respectively (P = .05). The prevalence of cesarean section and Apgar score < 7 were not significantly different (P > .05). Real-life clinical experiences suggested significant advantages of intravenous labetalol over hydralazine in pregnant women with severe hypertension.

Morphology, intrafetal vascular pattern, and umbilical artery Doppler indices of acardiac twins

BACKGROUND

Twin reversed arterial perfusion (TRAP) sequence consists of acardiac twin (A) paradoxically perfused by pump twin (P) through an umbilical artery (UA). We proposed characterization of acardiac twins with intrafetal vascular pattern (IVP), and assessed its correlation with morphology and UA Doppler indices.

METHODS

We prospectively evaluated 21 cases of TRAP sequence. Morphology (acardia vs hemicardia) and IVP (simple vs complex) of acardiac twins were characterized with ultrasound and color Doppler. Twins weight ratio (A/P Wt) and UA Doppler indices of acardiac and pump twins including (1) difference of systolic/diastolic ratio (UA ∆S/D), (2) difference of resistance index (UA ∆RI), and (3) ratio of pulsatility index (UA PI A/P) were calculated.

RESULTS

The median (min, max) gestational age at diagnosis was 18 (11, 27) weeks. Acardia (n = 14) were associated with simple IVP (n = 16) (P < .05). After exclusion of acardia with complex IVP (n = 1), the A/P Wt, UA ∆S/D, UA ∆RI, and UA PI A/P of acardia with simple IVP (n = 13), hemicardia with simple IVP (n = 3), and hemicardia with complex IVP (n = 4) were not significantly different (P > .05).

CONCLUSIONS

Most of acardiac twins were acardia with simple IVP. Morphology and IVP of acardiac twins were not associated with UA Doppler indices.

Clinical performance of DNA-based prenatal screening using single-nucleotide polymorphisms approach in Thai women with singleton pregnancy

Background

To review the performance of noninvasive prenatal screening (NIPS) using targeted single‐nucleotide polymorphisms (SNPs) approach in mixed‐risk Thai women.

Methods

Retrospective analysis of data for detection of trisomy 21 (T21), 18 (T18), 13 (T13), monosomy X (XO), other sex chromosome aneuploidies (SCA), and triploidy/vanishing twins (VT) from a single commercial laboratory.

Results

Mean (±SD) gestational age and maternal weight were 13.2 (±2.1) weeks and 125.7 (±22.4) pounds, respectively (n = 8,572). From 462/8,572 (5.4%) no‐calls; 1/462 (0.2%) was uninformative SNPs, and 1/462 chose amniocentesis. Redraw settled 323/460 (70%) samples with low fetal fraction (FF); and 8,434/8,572 (98.4%) were finally reportable, with 131 high risks (1.6%). The median (min‐max) FF of reportable (n = 8,434) and unreportable samples (n = 137) samples were 10.5% (2.6–37.9) and 3.8% (1–14.1), respectively (p < .05). Fetal karyotypes were available in 106/131 (80.9%) and 52/138 (37.7%) high risk and repeated no‐calls, respectively. The positive predictive values (PPVs) for T21 (n = 47), T18 (n = 15), T13 (n = 7), XO (n = 8), other SCA (n = 7), and triploidy/VT were 94%, 100%, 58.3%, 66.7%, 70%, and 57.1%, respectively. None of repeated no‐calls had aneuploidies.

Conclusion

SNP‐based NIPS has high PPVs for T21 and T18. Although the proprietary SNPs library is not population‐specific, uninformative SNPs are uncommon.

Additional benefits of three-dimensional ultrasound for prenatal assessment of twins

Three-dimensional ultrasound (3DUS) may provide additional information for prenatal assessment of twins. It may improve the diagnostic confidence of dating, nuchal translucency (NT) and chorionicity assignment in twin pregnancies. The "virtual 3DUS placentoscopy" can guide selective fetoscopic laser photocoagulation (SFLP) to treat twin-twin transfusion syndrome (TTTS). Volumetric assessment of the dysmorphic acardiac twin with the Virtual Organ Computer-aided Analysis (VOCAL) software is more accurate than the conventional ultrasound measurement. Twin anemia polycythemia (TAP) sequence and selective intrauterine growth restriction (sIUGR) may be clinically monitored with 3DUS placental volume (PV) and power Doppler vascular indices. Congenital anomalies are more common in twins. Evaluation of fetal anomalies with 3DUS could assist perinatal management. The 3DUS power Doppler can provide a better understanding of true and false umbilical cord knots, which are commonly found in monoamniotic (MA) twins. Single demise in monochorionic (MC) twin pregnancies can cause severe neurologic morbidity in the surviving co-twin. Prenatal prediction of brain injury in the surviving co-twin with unremarkable neurosonographic examination is difficult. The 3DUS power Doppler may aid in prenatal detection of subtle abnormal cerebral perfusion. Prenatal assessment of conjoined twins with 3DUS is important if emergency postnatal surgical separation is anticipated. There is no significant additional advantage in using real-time 3DUS to guide prenatal interventions. Assessment of the cervix and pelvic floor during twin pregnancies is enhanced with 3DUS. Due to lack of high-quality studies, routine prenatal 3DUS in twin pregnancies needs to be balanced with risks of excessive ultrasound exposure.

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.

Intrapartum prediction of birth weight with a simplified algorithmic approach derived from maternal characteristics

Objective To derive and validate a population-specific multivariate approach for birth weight (BW) prediction based on quantitative intrapartum assessment of maternal characteristics by means of an algorithmic method in low-risk women. Methods The derivation part (n = 200) prospectively explored 10 variables to create the best-fit algorithms (70% correct estimates within ±10% of actual BW) for prediction of BW at term; vertex presentation with engagement. The algorithm was then cross validated with samples of unrelated cases (n = 280) to compare the accuracy with the routine abdominal palpation method. Results The best-fit algorithms were parity-specific. The derived simplified algorithms were (1) BW (g) = 100 [(0.42 × symphysis-fundal height (SFH; cm)) + gestational age at delivery (GA; weeks) - 25] in nulliparous, and (2) BW (g) = 100 [(0.42 × SFH (cm)) + GA - 23] in multiparous. Cross validation showed an overall 69.3% accuracy within ±10% of actual BW, which exceeded routine abdominal palpation (60.4%) (P = 0.019). The algorithmic BW prediction was significantly more accurate than routine abdominal palpation in women with the following characteristics: BW 2500-4000 g, multiparous, pre-pregnancy weight <50 kg, current weight <60 kg, height <155 cm, body mass index (BMI) <18.5 kg/m2, cervical dilatation 3-5 cm, station <0, intact membranes, SFH 30-39 cm, maternal abdominal circumference (mAC) <90 cm, mid-upper arm circumference (MUAC) <25 cm and female gender of the neonates (P < 0.05). Conclusion An overall accuracy of term BW prediction by our simplified algorithms exceeded that of routine abdominal palpation.

Retrospective analysis of 113 consecutive cases of placenta accreta spectrum from a single tertiary care center

Objective: Placenta accreta spectrum (PAS) remains a major cause of maternal morbidity. We sought to assess the characteristics and treatment outcomes of PAS managed at a tertiary care center with high volume of PAS.Study design: Electronic medical records of all patients with diagnosis of PAS from June 2010 to October 2016 were reviewed. Details of obstetric backgrounds, predelivery diagnosis, peripartum management, and outcomes were analyzed.Results: One hundred thirteen women with PAS were identified from 50,448 deliveries during the study period. Vaginal delivery, emergency, and elective cesarean section were accomplished in 41.6, 30.1, and 28.3%, respectively. There was no maternal mortality. Approximately 41.6% of women with PAS had peripartum hysterectomy. There was a fair inverse correlation between intraoperative blood loss and gestational weeks at delivery (r = -0.311; p=.001), but not gestational weeks at diagnosis (p = .249). Cases with predelivery diagnosis (n = 29) had higher intraoperative blood loss than those diagnosed postdelivery (n = 84) (p<.001). Anterior PAS (n = 58) is associated with attachment to previous uterine scar, antepartum bleeding, and intraoperative blood loss compared to posterior PAS (n = 44) (p<.05). The PAS patients with previous uterine surgery had the highest chance of peripartum hysterectomy (p<.001).Conclusions: Contradictory to previous reports, our data suggest a more severe spectrum of PAS in those with predelivery detection earlier gestational weeks at delivery. Peripartum hysterectomy was highest in anterior PAS that attached to the previous uterine scar.

A retrospective review of on-admission factors on attainment of therapeutic serum concentrations of magnesium sulfate in women treated for a diagnosis of preeclampsia

Introduction: There is little information on the effect of maternal characteristics and on-admission laboratory parameters to the therapeutic serum magnesium sulfate (MgSO₄) levels in women with preeclampsia (PE). We sought to identify factors that may predict timely attainment of therapeutic serum magnesium levels after intravenous administration for seizure prophylaxis.Materials and methods: On-admission factors of 360 women with PE who received intravenous MgSO₄ (4-g loading and 2-g/h maintenance) for seizure prophylaxis were retrospectively reviewed. Parameters of those who attained therapeutic serum concentrations (4.8-8.4 mg/dL) within 2 h (Group A) and those who did not (Group B) were compared.Results: There was no seizure or magnesium toxicity in this cohort. Median (min-max) level of serum magnesium was 4.3 (2.5-8.4) mg/dL. Women in Group A (n = 105) had lower gestational age, body mass index (BMI), and platelets count, higher blood urea nitrogen (BUN), serum creatinine, uric acid, direct bilirubin, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, prothrombin, and partial thromboplastin times than those in Group B (n = 255) (p < .05). Women with mild PE were less likely to attain therapeutic serum magnesium levels compared with those with severe phenotypes (adjusted OR 23.57, 95% CI 8.20-67.76 versus adjusted OR 14.72, 95% CI 3.56-60.89, respectively; p < .05), which may be explained by their significantly lower serum BUN and uric acid (p < .05).Conclusions: On-admission factors, especially BMI and renal clearance indices, of women with PE may affect timely attainment of therapeutic serum magnesium levels. Validation of its clinical impact requires further study focusing on women with severe PE.

Time and temperature dependence of radiofrequency ablation in the human placenta

OBJECTIVE

The objective of the study is to compare radiofrequency (RF) effects on fresh placentae with varying levels of sustained time (Ts) and degrees of target temperature (°t).

METHOD

A total of 108 pieces of fresh placentae were coagulated with a 2-cm RF needle at 60 W in an organ bath. The vertical and horizontal diameters (Vd, Hd) of tissue coagulation visualized by ultrasound were measured. The impacts of 12 different Ts-°t combinations on the ablation size ascertained on pathological examination (Vd_p , Hd_p ) were compared using 2-way ANOVA. The agreement between sonographic and pathological findings was assessed using Bland-Altman analysis.

RESULTS

Considerable changes in the Vd_p and Hd_p were associated with increasing the Ts and °t. The impact of RF on tissue coagulation was greatest when the °t was set at 100°C, with further destruction as the Ts progressed to 7 minutes of exposure. The ablation size estimated by ultrasound exhibited an overestimation by an average of 5.65% and 21.02% for Vd and Hd, respectively.

CONCLUSION

A prolonged Ts at a higher °t contributes to progressive placental tissue destruction by RF, with maximum destruction at 100°C for 7 minutes in an ex vivo nonperfused placenta. Tissue injury that is apparent on ultrasound may extend beyond pathological damage.

Advanced ultrasound for prenatal interventions

Ultrasound is an integral part of prenatal interventions. Doppler studies and 3-dimensional ultrasound (3DUS) are frequently used to determine whether fetal surgery is required. The operator's experience remains crucial for reducing procedure-related morbidity. Real-time 3DUS (or 4DUS) can simultaneously display the needle tip in three orthogonal planes, providing reassurance that no fetal parts are in the path. In experienced hands, 4DUS guidance may not be more effective than B-mode, but its value for less-experienced operators remains to be determined. Recent developments in needle, shunt, and video endoscopic technologies may compliment the use of image-guided in utero procedures. Future developments of higher-dimensional transducers and image software may improve the utility of ultrasound for invasive obstetric interventions.

Model Surgical Training: Skills Acquisition in Fetoscopic Laser Photocoagulation of Monochorionic Diamniotic Twin Placenta Using Realistic Simulators

Fetoscopic laser coagulation of arterio-venous anastomoses (AVA) in a monochorionic placenta is the standard of care for twin-twin transfusion syndrome (TTTS), but is technically challenging and can lead to significant complications. Acquiring and maintaining the necessary surgical skills require consistent practice, a critical caseload, and time. Training on realistic surgical simulators can potentially shorten this steep learning curve and enables several proceduralists to acquire procedure-specific skills simultaneously. Here we describe realistic simulators designed to allow the user familiarity with the equipment and specific steps required in the surgical treatment of TTTS, including fetoscopic handling, approaches to anterior and posterior placenta, recognition of anastomoses, and efficient coagulation of vessels. We describe the skills that are especially important in conducting placental laser coagulation that the surgeon can practice on the model and apply in a clinical case. These models can be adapted easily depending on the availability of materials and require standard fetoscopy equipment. Such training systems are complementary to traditional surgical apprenticeships and can be useful aids for fetal medicine units that provide this clinical service.

Prediction and prevention of pre-eclampsia in Asian subpopulation

The benefit of the early administration of aspirin to reduce preterm pre-eclampsia among screened positive European women from multivariate algorithmic approach (ASPRE trial) has opened an intense debate on the feasibility of universal screening. This review aims to assess the new perspectives in the combined screening of pre-eclampsia in the first trimester of pregnancy and the chances for prevention using low-dose aspirin with special emphasis on the particularities of the Asian population. PubMed, CENTRAL and Embase databases were searched from inception until 15 November 2017 using combinations of the search terms: preeclampsia, Asian, prenatal screening, early prediction, ultrasonography, pregnancy, biomarker, mean arterial pressure, soluble fms-like tyrosine kinase-1, placental growth factor, pregnancy-associated plasma protein-A and pulsatility index. This is not a systematic review or meta-analysis, so the risk of bias of the selected published articles and heterogeneity among the studies need to be considered. The prevalence of pre-eclampsia and serum levels of biochemical markers in Asian are different from Caucasian women; hence, Asian ethnicity needs to be corrected for in the algorithmic assessment of multiple variables to improve the screening performance. Aspirin prophylaxis may still be viable in Asian women, but resource implication needs to be considered. Asian ethnicity should be taken into account before implementing pre-eclampsia screening strategies in the region. The variables included can be mixed and matched to achieve an optimal performance that is appropriate for economical restriction in individual countries.

Circulating soluble fms-like tyrosine kinase-1 and placental growth factor from 10 to 40 weeks' pregnancy in normotensive women

INTRODUCTION

Circulating soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) are potential markers for preeclampsia. The objective was to construct and analyse the reference ranges of serum levels of sFlt-1 and PlGF throughout the course of pregnancy in low-risk Thai pregnant women.

METHODS

We enrolled 110 low-risk, Thai women singleton pregnancy from 10 to 40 gestational weeks. Serum concentrations of sFlt-1 and PlGF were measured with an automated assay. The reference ranges of serum levels of sFlt-1, PlGF and sFlt-1/PlGF ratio were constructed and assessed for possible correlations with gestational age, maternal factors [age, parity, tobacco use, artificial reproductive technologies (ARTS) and body mass index (BMI)], and pregnancy outcomes (gestational age at delivery, development of preeclampsia, neonatal birth weight and placental weight).

RESULTS

None of the subjects developed preeclampsia. Serum sFlt-1 concentrations significantly elevated from 20 to 40 gestational weeks (P=0.003). Significant elevation and dropping of serum PlGF levels and sFlt-1/PlGF ratios were observed at 10 to 29 and 30 to 40 weeks of gestation, respectively (P<0.001). There was an inversed correlation between serum PlGF levels at 20 to 29 gestational weeks and neonatal birth weights (r=-0.48, P<0.05). There were no associations between serum levels of sFlt-1, PlGF, or sFlt-1/PlGF ratios and maternal BMI, gestational age at delivery, or placental weight (P>0.05). Effects from parity, smoking and ARTS were inconclusive.

CONCLUSION

Robust change of serum PlGF levels suggests for its broader clinical application compared to sFlt-1. Prediction of preeclampsia using serum analytes may be gestational period specific.

Three-dimensional ultrasound for prenatal assessment of conjoined twins: additional advantages?

Conjoined twins are a rare, but serious, complication of monozygotic twins. Early prenatal diagnosis of conjoined twins is increasingly made with transvaginal ultrasound and color Doppler studies. Most prenatally diagnosed conjoined twins are terminated due to the high perinatal mortality, but advancement in pediatric surgery has allowed for successful postnatal separation in a small number of cases, and some parents may consider this option over termination of pregnancy. It is important to get a detailed prenatal ultrasound for the site and extent of fusion for an accurate categorization. Three-dimensional ultrasound (3DUS) provides images that can facilitate counselling for the parents. Additional information that impacts on diagnosis, prognostication, and perinatal management of conjoined twins could be obtained from selective use of 3DUS, particularly those with atypical fetal union. Most of the proposed additional benefits of 3DUS are based on case reports. Magnetic resonance imaging (MRI) has been increasingly used for the purpose of identifying intricate organ sharing. Because of the rarity of this condition, and the heterogeneity of fetal fusion, added benefits of either 3DUS or MRI for prenatal diagnosis and perinatal management of conjoined twins have not been demonstrated by well-conducted clinical trials. This article aims to review clinical application of various 3DUS display modes in prenatal assessment of conjoined twins, focusing on their potential additional benefits, risks and misuses. 3DUS may help detecting additional findings that are not possible with 2DUS, but, it has not been scientifically shown to improve the survival rate of the twins or reduce maternal morbidity.

Rapid initiation of fetal therapy services with a system of learner-centred training under proctorship: the National University Hospital (Singapore) experience

INTRODUCTION

Management of complicated monochorionic twins and certain intrauterine structural anomalies is a pressing challenge in communities that still lack advanced fetal therapy. We describe our efforts to rapidly initiate selective feticide using radiofrequency ablation (RFA) and selective fetoscopic laser photocoagulation (SFLP) for twin-to-twin transfusion syndrome (TTTS), and present the latter as a potential model for aspiring fetal therapy units.

METHODS

Five pregnancies with fetal complications were identified for RFA. Three pregnancies with Stage II TTTS were selected for SFLP. While RFA techniques utilising ultrasonography skills were quickly mastered, SFLP required stepwise technical learning with an overseas-based proctor, who provided real-time hands-off supervision.

RESULTS

All co-twins were live-born following selective feticide; one singleton pregnancy was lost. Fetoscopy techniques were learned in a stepwise manner and procedures were performed by a novice team of surgeons under proctorship. Dichorionisation was completed in only one patient. Five of six twins were live-born near term. One pregnancy developed twin anaemia-polycythaemia sequence, while another was complicated by co-twin demise.

DISCUSSION

Proctor-supervised directed learning facilitated the rapid provision of basic fetal therapy services by our unit. While traditional apprenticeship is important for building individual expertise, this system is complementary and may benefit other small units committed to providing these services.

Delivery modes in case of fetal malformations

An estimated 276,000 babies die within 4 weeks of birth every year, worldwide, from congenital anomalies. Better quality ultrasound screening can increase the detection of these fetal malformations in the prenatal period. Prenatal counseling for the pregnant woman and her family, regarding the nature of the disease and prognosis is necessary. Options for management in prenatal, perinatal, intrapartum, neonatal, and childhood periods need to be thoroughly discussed, so that the family can make an informed decision. A multidisciplinary approach is usually needed once a decision has been made to optimize fetal outcome, to plan for the timing and location as well as the mode of delivery. In most of the cases, vaginal delivery can be attempted. An elective cesarean delivery should be reserved for maternal concern of dystocia, certain fetal conditions that cesarean delivery will optimize perinatal outcome, or if the parents have a psychosocial determination to have a live-born infant.

Is intrauterine surgery justified? Report from the working group on ultrasound in obstetrics of the World Association of Perinatal Medicine (WAPM)

Fetal surgery involves a large number of heterogeneous interventions that vary from simple and settled procedures to very sophisticated or still-in-development approaches. The overarching goal of fetal interventions is clear: to improve the health of children by intervening before birth to correct or treat prenatally diagnosed abnormalities. This article provides an overview of fetal interventions, ethical approaches in fetal surgery, and benefits obtained from antenatal surgeries.

Fetal magnetic resonance imaging and ultrasound

Magnetic resonance imaging (MRI) has been increasingly adopted in obstetrics practice in the past three decades. MRI aids prenatal ultrasound and improves diagnostic accuracy for selected maternal and fetal conditions. However, it should be considered only when high-quality ultrasound cannot provide certain information that affects the counseling, prenatal intervention, pregnancy course, and delivery plan. Major indications of fetal MRI include, but are not restricted to, morbidly adherent placenta, selected cases of fetal brain anomalies, thoracic lesions (especially in severe congenital diaphragmatic hernia), and soft tissue tumors at head and neck regions of the fetus. For fetal anatomy assessment, a 1.5-Tesla machine with a fast T2-weighted single-shot technique is recommended for image requisition of common fetal abnormalities. Individual judgment needs to be applied when considering usage of a 3-Tesla machine. Gadolinium MRI contrast is not recommended during pregnancy. MRI should be avoided in the first half of pregnancy due to small fetal structures and motion artifacts. Assessment of fetal cerebral cortex can be achieved with MRI in the third trimester. MRI is a viable research tool for noninvasive interrogation of the fetus and the placenta.

3D/4D sonography - any safety problem

Gray-scale image data are processed in 3D ultrasound by repeated scans of multiple planes within a few seconds to achieve one surface rendering image and three perpendicular plane images. The 4D image is achieved by repeating 3D images in short intervals, i.e. 3D and 4D ultrasound are based on simple B-mode images. During 3D/4D acquisition, a fetus in utero is exposed by ultrasound beam for only a few seconds, and it is as short as real-time B-mode scanning. Therefore, simple 3D imaging is as safe as a simple B-mode scan. The 4D ultrasound is also as safe as a simple B-mode scan, but the ultrasound exposure should be shorter than 30 min. The thermal index (TI) and mechanical index (MI) should both be lower than 1.0, and the ultrasound study is regulated by the Doppler ultrasound if it is combined with simple 3D or 4D ultrasound. Recently, some articles have reported the functional changes of animal fetal brain neuronal cells and liver cell apoptosis with Doppler ultrasound. We discuss cell apoptosis by ultrasound in this report. Diagnostic ultrasound safety is achieved by controlling the output pulse and continuous ultrasound waves using thermal and mechanical indices, which should be <1.0 in abdominal and transvaginal scan, pulsed Doppler, as well as 3D and 4D ultrasound. The lowest spatial peak temporal average (SPTA) intensity of the ultrasound to suppress cultured cell growth is 240 mW/cm2, below which no ultrasound effect has been reported. An ultrasound user must be trained to recognize the ultrasound bioeffects; thermal and mechanical indices, and how to reduce these when they are higher than 1.0 on the monitor display; and guide the proper use of the ultrasound under the ALARA principle, because the user is responsible for ensuring ultrasound safety.

Controversial ultrasound findings in mid trimester pregnancy. Evidence based approach

Mid trimester fetal anatomy scan is a fundamental part of routine antenatal care. Some U/S soft markers or controversial U/S signs are seen during the scan and create some confusion regarding their relation to fetal chromosomal abnormalities. Example of these signs: echogenic focus in the heart, echogenic bowel, renal pyelectasis, ventriculomegaly, polydactely, club foot, choroid plexus cyst, single umbilical artery. We are presenting an evidence based approach from the literature for management of these controversial U/S signs.

Ultrasound in Africa: what can really be done?

Today we are living in a globalized world in which information on what is happening in one part of the world is easily communicated to other parts of the world. This happens thanks to advancement in science and technology. One area where technology has made the greatest impact is heath care provision. Ultrasound technology is now playing a critical role in health care provision particularly in Obstetrics and Gynaecology. This has significantly assisted in provision of quality health care to pregnant women and their unborn infants and in reducing maternal and neonatal morbidity and mortality in the developed world. Africa the continent with greatest health care challenges and with the highest maternal and neonatal mortalities is yet to fully utilize this important technology. The need for this technology is great as the conditions requiring its application abound. The effective application of Ultrasound however faces serious challenges in Africa. To successfully entrench Ultrasound in quality Obstetrics and Gynaecology care various approaches must be adopted to overcome the challenges. The aim of this paper is to identify the benefits and the challenges inimical to the application Ultrasound in Obstetrics and Gynecology in Africa. It also examines what needs to be done to achieve better application of Ultrasound in Obstetrics and Gynecology.

Fetal Anomalies in Twin Pregnancies

Twinning increases the chances of structural anomaly in the fetus. Discordance in physical development of the fetuses raises both ethical and management dilemma. Chorionicity plays an important role when selective feticide is an option. Anomalies found in singleton pregnancy can also be found in twins. Certain anomalies, such as acardiac fetus, are unique to monochorionic (MC) twin gestations. These anomalies may require in utero intervention to salvage its normal co-twin. Structural abnormalities, such as obstruction in fetal gastrointestinal tract resulting in polyhydramnios, can threaten the loss of the whole pregnancy. In MC twins, demise of the anomalous fetus can result in either demise or cerebral palsy of its co-twin. Fetal cord occlusion of the anomalous fetus can be offered to prevent these deleterious effects to its normal co-twin. Discordance of karyotypes in dichorionic (DC) twins is increasingly diagnosed in prenatal period. Selective feticide in this situation is simpler, but more ethical concerns are being raised. The technical and ethical considerations related to various kinds of discordance fetal malformations in the twin pair will be discussed in this review article.

How to cite this article

Wataganara T, Nawapun K, Phithakwatchara N. Fetal Anomalies in Twin Pregnancies. Donald School J Ultrasound Obstet Gynecol 2016;10(3):308-312.

Maternal Vitamin D Status and Its Related Factors in Pregnant Women in Bangkok, Thailand

Background

There are few data focusing on the prevalence of vitamin D deficiency in tropical countries.

Objectives

We determined the vitamin D status in pregnant women and examined the factors associated with vitamin D deficiency.

Design and Methods

A cross-sectional study of 147 pregnant Thai women aged 18–45 years at Siriraj Hospital (a university hospital in Bangkok, Thailand) was undertaken. Clinical data and plasma levels of 25-hydroxyvitamin D [25(OH)D], intact parathyroid hormone (iPTH), calcium, albumin, phosphate and magnesium were obtained in pregnant women at delivery.

Results

The prevalence of hypovitaminosis D [defined as 25(OH)D <75 nmol/L] in pregnant women at delivery was 75.5% (95% confidence interval (CI), 67.7–82.2%). Of these, vitamin D insufficiency [defined as 25(OH)D 50–74.9 nmol/L] was found in 41.5% (95% CI, 33.4–49.9%) and vitamin D deficiency [25(OH)D <50 nmol/L] was found in 34.0% (95% CI, 26.4–42.3%) of women. The mean 25(OH)D concentration was 61.6±19.3 nmol/L. The correlation between 25(OH)D and iPTH was weak (r = –0.29, P<0.01). Factors associated with vitamin D deficiency by multiple logistic regression were: pre-pregnancy body mass index (BMI in kg/m², odds ratio (OR), 0.88, 95% CI 0.80–0.97, P = 0.01) and season of blood collection (winter vs. rainy, OR, 2.62, 95% CI 1.18–5.85, P = 0.02).

Conclusions

Vitamin D deficiency is common among pregnant Thai women. The prevalence of vitamin D deficiency increased in women who had a lower pre-pregnancy BMI and whose blood was collected in the winter. Vitamin D supplementation may need to be implemented as routine antenatal care.

Fetal long QT syndrome manifested as atrioventricular block and ventricular tachycardia: a case report and a review of the literature

Fetal onset of congenital long QT syndrome (LQTS) is a rare manifestation, and prenatal diagnosis is difficult. This report describes a boy who presented with both atrioventricular (AV) block and ventricular tachycardia during the antenatal period. The early postnatal electrocardiogram showed prolongation of the QT interval and AV block, subsequently leading to a polymorphic ventricular tachycardia torsade de pointes. This unique feature of congenital LQTS has a poor outcome, but the boy was successfully treated with beta-blockers and implantation of an automated cardioverter-defibrillator. The intrauterine manifestation of fetal AV block and ventricular tachycardia should raise a high suspicion of congenital LQTS, and the strong association with a malignant clinical course should warrant special evaluation. The literature on the prenatal diagnosis, fetal therapy, and neonatal outcome of this condition also are reviewed.

PP122. Lack of correlation between placental weight and circulating soluble fms-like tyrosine kinase-1 and placental growth factor suggests trophoblastic activity as a major contributor to the serum pool

INTRODUCTION

Serum levels of soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) are altered in preeclampsia and fetal growth restriction. Whether the alterations result from mere variation in trophoblastic mass or trophoblastic activity in these diseases is still elusive.

OBJECTIVES

Using placental weight as a surrogate for trophoblastic mass, we explored the relationship between placental weight at delivery and serum levels of sFlt-1 and PlGF at various gestational ages in normotensive pregnant Thai women.

METHODS

One hundred and forty two serum samples from healthy, normotensive, singleton Thai pregnant women were prospectively collected from 6 gestational age intervals; 10-14, 15-19, 20-24, 25-29, 30-34, and 35-40weeks'. Analysis for the levels of sFlt-1 and PlGF was made from fresh specimens, using a commercially available automated system. Placental weight at delivery was followed in participants who remained unaffected with preeclampsia or fetal growth restriction until the time of delivery.

RESULTS

Statistical analyses were achieved from 140 participants. Quartiles for these markers were calculated for each gestational age interval. Serum sFlt-1 levels continuously increased through the pregnancy. Serum PlGF levels reached its peak levels at menstrual period of 25-29weeks', and then declined. Serum sFlt-1/PlGF ratios were consistently lower than that of the European population throughout the pregnancy. No significant correlation is found between placental weight at delivery, and serum levels of either sFlt-1 or PlGF at any gestational age interval.

CONCLUSION

Ethnic variation of serum angiogenic markers is shown in this study. Lack of correlation between placental weight and serum angiogenic markers in normotensive individuals suggest that trophoblastic activity, and not number of the trophoblast, contribute to the alterations in circulating pool. This may facilitate a better understanding for its potential clinical applications of these biomarkers for other placental related diseases.