First alongside midwifery led unit in a high complexity public hospital in Spain: Maternal and neonatal outcomes

PROBLEM

Midwifery led units are rare in Spain.

BACKGROUND

Midwife-Led Care (MLC) is a widely extended model of care and, within this, the alongside midwifery-led units (AMLU) are those hospital-based and located in close connection with obstetric units. In Spain, CL is the first center belonging to the National Health System of these characteristics.

AIM

To evaluate the first year of activity of this pioneering unit.

METHODS

An observational cross-sectional study was carried out to assess maternal and neonatal outcomes of births facilitated at CL by comparing with those births that fulfilled the criteria to be admitted at the AMLU but were assisted at the standard obstetric care unit of the hospital.

FINDINGS

174 (20,3%) women and birthing people decided to give birth at CL, whereas 684 (79,7%) gave birth at the Obstetric Unit of the Hospital. Women assisted at the AMLU had lower intervention rates (episiotomy, epidural analgesia) and a higher rate of breastfeeding practice. There were no statistical differences in maternal outcomes (postpartum hemorrhage, third-or-four-degree laceration) or neonatal outcomes (Apgar< 7 at 5 min; birth weight < 2500 gr; macrosomia; shoulder dystocia, neonatal care transfer).

DISCUSSION

There were differences in transfers from MLU to OU between nulliparous and multiparous; the main reason for transfer is the request for analgesia. Epidural analgesia should be considered when analyzing maternal outcomes.

CONCLUSION

An alongside midwifery-led unit is a safe option with a low incidence of complications. This model of care can be positively implemented at the Public Healthcare System.

Multicentre randomised trial of screening with sFlt1/PlGF and planned delivery to prevent pre-eclampsia at term: protocol of the PE37 study

INTRODUCTION

Pre-eclampsia affects ~5%-7% of pregnancies. Although improved obstetric care has significantly diminished its associated maternal mortality, it remains a leading cause of maternal morbidity and mortality in the world. Term pre-eclampsia accounts for 70% of all cases and a large proportion of maternal-fetal morbidity related to this condition. Unlike in preterm pre-eclampsia, the prediction and prevention of term pre-eclampsia remain unsolved. Previously proposed approaches are based on combined third-trimester screening and/or prophylactic drugs, but these policies are unlikely to be widely implementable in many world settings. Recent evidence shows that the soluble fms-like tyrosine kinase-1 (s-Flt-1) to placental growth factor (PlGF) ratio measured at 35-37 weeks' gestation predicts term pre-eclampsia with an 80% detection rate. Likewise, recent studies demonstrate that induction of labour beyond 37 weeks is safe and well accepted by women. We hypothesise that a single-step universal screening for term pre-eclampsia based on sFlt1/PlGF ratio at 35-37 weeks followed by planned delivery beyond 37 weeks reduces the prevalence of term pre-eclampsia without increasing the caesarean section rates or worsening the neonatal outcomes.

METHODS AND ANALYSIS

We propose an open-label randomised clinical trial to evaluate the impact of a screening of term pre-eclampsia with the sFlt-1/PlGF ratio followed by planned delivery in asymptomatic nulliparous women at 35-37 weeks. Women will be assigned 1:1 to revealed (sFlt-1/PlGF known to clinicians) versus concealed (unknown) arms. A cut-off of >90th centile is used to define the high risk of subsequent pre-eclampsia and offer planned delivery from 37 weeks. The efficacy variables will be analysed and compared between groups primarily following an intention-to-treat approach, by ORs and their 95% CI. This value will be computed using a Generalised Linear Mixed Model for binary response (study group as fixed effect and the centre as intercept random effect).

ETHICS AND DISSEMINATION

The study is conducted under the principles of Good Clinical Practice. This study was accepted by the Clinical Research Ethics Committee of Hospital Clinic Barcelona on 20 November 2020. Subsequent approval by individual ethical committees and competent authorities was granted. The study results will be published in peer-reviewed journals and disseminated at international conferences.

TRIAL REGISTRATION NUMBER

NCT04766866.

Modeling road traffic safety based on point patterns of wildlife-vehicle collisions

Wildlife-vehicle collisions represent one of the main coexistence problems that appear between human populations and the environment. In general terms, this affects road safety, wildlife management, and the building of road infrastructures. These accidents are a great danger to the life and safety of car drivers, cause property damage to vehicles, and affect wildlife populations. In this work, we develop a new approach based on algorithms used to obtain minimum paths between vertices in weighted networks to get the optimal (safest) route between two points (departure and destination points) in a road structure based on wildlife-vehicle collision point patterns together with other road variables such as traffic volume (traffic flow information), road speed limits, and vegetation density around roads. For this purpose, we have adapted the road structure into a mathematical linear network as described in the field of Graph Theory and added weights to each linear segment based on the intensity of accidents. Then, the resulting network structure allows us to consider some graph theory methodologies to manipulate and apply different calculations to analyze the network. This new approach has been illustrated with a real data set involving the locations of 491 wildlife-vehicle collisions in a square region (40 km × 40 km) around the city of Lleida, during the period 2010-2014, in the region of Catalonia, North-East of Spain. Our results show the usefulness of our new approach to model road traffic safety based on point patterns of wildlife-vehicle collisions. As such, optimal path selection on linear networks based on wildlife-vehicle collisions can be considered to find the safest path between two pairs of points, avoiding more dangerous routes and even routes containing hotspots of accidents.

Neurofibromatosis type 1 families with first-degree relatives harbouring distinct NF1 pathogenic variants. Genetic counselling and familial diagnosis: what should be offered?

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder caused by pathogenic variants in NF1 Recently, NF1 testing has been included as a clinical criterion for NF1 diagnosis. Additionally, preconception genetic counselling in patients with NF1 focuses on a 50% risk of transmitting the familial variant as the risk of having a sporadic NF1 is considered the same as the general population.

METHODS

829 individuals, 583 NF1 sporadic cases and 246 patients with NF1 with documented family history, underwent genetic testing for NF1. Genotyping and segregation analysis of NF1 familial variants was determined by microsatellite analysis and NF1 sequencing.

RESULTS

The mutational analysis of NF1 in 154 families with two or more affected cases studied showed the co-occurrence of two different NF1 germline pathogenic variants in four families. The estimated mutation rate in those families was 3.89×10^-3, 20 times higher than the NF1 mutation rate (~2×10^-4) (p=0.0008). Furthermore, the co-occurrence of two different NF1 germline pathogenic variants in these families was 1:39, 60 times the frequency of sporadic NF1 (1:2500) (p=0.003). In all cases, the de novo NF1 pathogenic variant was present in a descendant of an affected male. In two cases, variants were detected in the inherited paternal wild-type allele.

CONCLUSIONS

Our results, together with previous cases reported, suggest that the offspring of male patients with NF1 could have an increased risk of experiencing de novo NF1 pathogenic variants. This observation, if confirmed in additional cohorts, could have relevant implications for NF1 genetic counselling, family planning and NF1 genetic testing.

Assessment of an intervention to optimise antenatal management of women admitted with preterm labour and intact membranes using amniocentesis-based predictive risk models: study protocol for a randomised controlled trial (OPTIM-PTL Study)

INTRODUCTION

The majority of women admitted with threatened preterm labour (PTL) do not delivery prematurely. While those with microbial invasion of the amniotic cavity (MIAC) represent the highest risk group, this is a condition that is not routinely ruled out since it requires amniocentesis. Identification of low-risk or high-risk cases might allow individualisation of care, that is, reducing overtreatment with corticosteroids and shorten hospital stay in low-risk women, while allowing early antibiotic therapy in those with MIAC. Benefits versus risks of amniocentesis-based predictor models of spontaneous delivery within 7 days and/or MIAC have not been evaluated.

METHODS AND ANALYSIS

This will be a Spanish randomised, multicentre clinical trial in singleton pregnancies (23.0-34.6 weeks) with PTL, conducted in 13 tertiary centres. The intervention arm will consist in the use of amniocentesis-based predictor models: if low risk, hospital discharge within 24 hours of results with no further medication will be recommended. If high risk, antibiotics will be added to standard management. The control group will be managed according to standard institutional protocols, without performing amniocentesis for this indication. The primary outcome will be total antenatal doses of corticosteroids, and secondary outcomes will be days of maternal stay and the occurrence of clinical chorioamnionitis. A cost analysis will be undertaken. To observe a reduction from 90% to 70% in corticosteroid doses, a reduction in 1 day of hospital stay (SD of 2) and a reduction from 24% to 12% of clinical chorioamnionitis, a total of 340 eligible patients randomised 1 to 1 to each study arm is required (power of 80%, with type I error α=0.05 and two-sided test, considering a dropout rate of 20%). Randomisation will be stratified by gestational age and centre.

ETHICS AND DISSEMINATION

Prior to receiving approval from the Ethics Committee (HCB/2020/1356) and the Spanish Agency of Medicines and Medical Devices (AEMPS) (identification number: 2020-005-202-26), the trial was registered in the European Union Drug Regulating Authorities Clinical Trials database (2020-005202-26). AEMPS approved the trial as a low-intervention trial. All participants will be required to provide written informed consent. Findings will be disseminated through workshops, peer-reviewed publications and national/international conferences.

PROTOCOL VERSION

V.4 10 May 2021.

TRIAL REGISTRATION NUMBERS

NCT04831086 and Eudract number 2020-005202-26.

COVID-19 and pregnancy: An opportunity to correct an historic gender bias

Current literature and clinical guidelines do not include pregnant women as an a priori risk group for COVID‐19. However, a gender vision of health begs the question: Why are pregnant women not considered a risk group for COVID‐19? The answer is clear: historically, most community scientific studies have not considered female gender, or pregnancy as a state, to be a focus of special interest or effort. Unfortunately, this bias seems to be maintained in the COVID‐19 epidemic: most current guidelines for diagnosing SARS‐CoV‐2 infection during pregnancy apply the same standard criteria as for the general population.

Improving fire season definition by optimized temporal modelling of daily human-caused ignitions

Wildfire suppression management is usually based on fast control of all ignitions, especially in highly populated countries with pervasive values-at-risk. To minimize values-at-risk loss by improving response time of suppression resources it is necessary to anticipate ignitions, which are mainly caused by people. Previous studies have found that human-ignition patterns change spatially and temporally depending on socio-economic activities, hence, the deployment of suppression resources along the year should consider these patterns. However, full suppression capacity is operational only within legally established fire seasons, driven by past events and budgets, which limits response capacity and increases damages out of them. The aim of this study was to assess the temporal definition of fire seasons from the perspective of human-ignition patterns for the case study of Spain, where people cause over 95% of fires. Humans engage in activities that use fire as a tool in certain periods within a year, and in locations linked to specific spatial factors. Geographic variables (population, infrastructures, physiography and land uses) were used as explanatory variables for human-ignition patterns. The changing influence of these geographic variables on occurrence along the year was analysed with day-by-day logistic regression models. Daily models were built for all the municipal units in the two climatic regions in Spain (Atlantic and Mediterranean Spain) from 2002 to 2014, and similar models were grouped within continuous periods, designated as ignition-based seasons. We found three ignition-based seasons in the Mediterranean region and five in the Atlantic zones, not coincidental with calendar seasons, but with a high degree of agreement with current legally designated operational fire seasons. Our results suggest that an additional late-winter-early-spring fire season in the Mediterranean area and the extension of this same season in the Atlantic zone should be re-considered for operational purposes in the future.

Prenatal Evaluation of the Fetal Conus Medullaris on a Routine Scan

Objective: To assess the ability to identify the conus medullaris (CM) and measure the conus-sacrum distance (CS distance) on a routine scan and the relationship with maternal and fetal factors. Methods: This was a prospective study. The assessment of the CM and the CS distance and the influence of the body mass index (BMI), gestational age (GA) and fetal position were analyzed. The correlation between the femur length (FL) and the GA with the CS distance was evaluated. Results: A total of 696 fetuses were analyzed. The CM could be visualized in 82.3% of the cases, and the CS distance could be analyzed in 81.2% of the cases. The CM assessment was statistically associated with BMI and fetal position but not with GA. The CS distance assessment was statistically associated with BMI and GA but not with fetal position. We determined a significant association between the FL/CS distance and between the GA/CS distance. Conclusions: Assessment of the CM is possible on most routine scans. The CS distance could be introduced to routine scans for the assessment of prenatal skin-covered spinal dysraphism. High BMI, advanced GA and breech presentation could be potential factors limiting the feasibility of evaluating the CM.

Initial experience with non-invasive prenatal testing of cell-free DNA for major chromosomal anomalies in a clinical setting

OBJECTIVE

To evaluate non-invasive prenatal testing (NIPT) of cell-free DNA (cfDNA) as a screening method for major chromosomal anomalies (CA) in a clinical setting.

METHODS

From January to December 2013, Panorama™ test or Harmony™ prenatal test were offered as advanced NIPT, in addition to first-trimester combined screening in singleton pregnancies.

RESULTS

The cohort included 333 pregnant women with a mean maternal age (MA) of 37 years who underwent testing at a mean gestational age of 14.6 weeks. Eighty-four percent were low-risk pregnancies. Results were provided in 97.3% of patients at a mean reporting time of 12.9 calendar days. Repeat sampling was performed in six cases and results were obtained in five of them. No results were provided in four cases. Four cases of Down syndrome were detected and there was one discordant result of Turner syndrome. We found no statistical differences between commercial tests except in reporting time, fetal fraction and MA. The cfDNA fraction was statistically associated with test type, maternal weight, BMI and log βhCG levels.

CONCLUSIONS

NIPT has the potential to be a highly effective screening method for major CA in a clinical setting.

Analysis of three different strategies in prenatal screening for Down's syndrome in twin pregnancies

OBJECTIVES

To compare the performance of three different strategies in prenatal screening for Down's syndrome in twins [nuchal translucency, the combined test, the combined test + ductus venosus pulsatility index (DVPI)].

METHODS

We included 277 twin pregnancies with two cases of trisomy 21 (both dichorionic). We performed a computer simulation of Down's syndrome NT screening, combined test screening and the combined test with the addition of DVPI screening using the commercialized software SsdwLab6. The strategies were compared using the area under the receiver operating characteristic curve.

RESULTS

NT screening false-positive rate (FPR) was 10.9% (95% CI: 8.3-13.5). The combined test FPR was 6.2% (95% CI: 4.1-8.2%) and the combined test plus DVPI was 6% (95% CI: 4-8). FPR was higher in advanced maternal age patients. Detection rate was 100% in all cases. The area under the curve was 0.987 (95% CI: 0.972-0.994) in NT screening; 0.987 (95% CI: 0.978-0.997) in the combined test and 0.983 (95% CI: 0.977-0.996) in the combined test + DVPI.

CONCLUSIONS

Down's syndrome screening is feasible in twins with low FPR. The results of this study are similar to the results achieved in singletons. The combined test appears to be the most effective. The addition of DVIP does not significantly improve the prenatal screening for trisomy 21.

Cumulative sum plots and retrospective parameters in first-trimester ductus venosus quality assurance

OBJECTIVE

This study aimed to evaluate the application of two quality assurance methods to the ductus venosus pulsatility index (DVPI), as a first-trimester aneuploidy marker, including retrospective assessment of distribution parameters and cumulative sum (CUSUM) plots.

METHODS

The DVPI was measured in 14 444 singleton fetuses at 11+0 to 13+6 weeks in two Fetal Medicine centers during a 4-year period. Sonologist-specific quality assurance distribution parameters, previously described for nuchal translucency, were assessed: the median multiples of the median (MoM), the logarithmic standard deviation of DVPI MoMs and the weekly DVPI percent decrease. Quality assurance results were compared between median MoMs and MoM-based CUSUM plots.

RESULTS

When sonologist-specific DVPI distribution parameters were retrospectively applied for quality assurance, a 1.0 median MoM, a 0.1 median logarithmic standard deviation and a 3.4 median weekly DVPI drop percentage were observed. CUSUM plots showed good agreement with 0.9-1.1 MoMs range for median MoM, in the assessment of sonologist-specific performances.

CONCLUSION

Retrospective and prospective DVPI quality assurance methods appear to be applicable to DVPI at 11+0 to 13+6 weeks. Its use should be encouraged if DVPI is to be added to first-trimester Down syndrome or cardiac defects screening.

First trimester risk assessment for trisomy 21 in twin pregnancies combining nuchal translucency and first trimester biochemical markers

OBJECTIVE

The aim is to describe the performance of first-trimester combined risk assessment in twin pregnancies.

METHODS

Maternal serum free beta-human chorionic gonadotrophin and pregnancy-associated plasma protein A (PAPP-A) were determined at 8 to 12 weeks and fetal nuchal translucency (NT) was measured at 11 to 13+6 weeks. The individual risk was estimated for each fetus using the combined test in dichorionic twins. In monochorionic twins, the mean risk assessment of the two fetuses was used. An invasive diagnostic procedure was offered when the risk was ≥ 1 : 270 in either one of the fetuses.

RESULTS

From February 2007 to June 2011, 447 twin pregnancies were enrolled in this study. There were 402 (89.9%) dichorionic and 45 (10.1%) monochorionic twins. In dichorionic twins, mean crown-rump length (CRL) was 63.9 mm; median NT multiples of the median (MoM) was 0.97; median Β-hCG was MoM 1.74; median PAPP-A was 1.72. In monochorionic twins, mean CRL was 61.9 mm; median NT MoM was 0. 98; median Β-hCG MoM was 1.44; and median PAPP-A was 1.51. Two pregnancies with Down syndrome were detected by first trimester screening, both in dichorionic twins. The false positive rate was 5.7% (95% confidence interval 4.1-7.3) and 4.4% (95% confidence interval 0.1-8.8%) in dichorionic and monochorionic twins, respectively.

CONCLUSIONS

The combined test in twins appears to be a good method for Down syndrome screening with a high detection rate and an acceptable false-positive rate.

Is the addition of the ductus venosus useful when screening for aneuploidy and congenital heart disease in fetuses with normal nuchal translucency?

OBJECTIVE

The aim of this study was to examine the possible role of Doppler ultrasound assessment of ductus venosus (DV) blood flow at 11⁺⁰-13⁺⁶ weeks' gestation in fetuses with normal nuchal translucency (NT) in screening for autosomal trisomies (AT) and for congenital heart diseases (CHD) in chromosomally normal fetuses.

METHODS

First-trimester combined screening for trisomy 21 (T21) was carried out prospectively for 7 years in singleton pregnancies. NT and the pulsatility index for DV (DVPI) were calculated. The DV was analyzed according to its association with AT and CHD. The detection rate (DR), false-positive rate (FPR), positive predictive value (PPV), and odds ratio (OR) for abnormal DV were calculated.

RESULTS

Abnormal DV as an early marker of euploid CHD gives a DR of 12.5%, an FPR of 4.3%, a PPV of 1.4%, and a negative predictive value (NPV) of 99.5%, with an OR of 3.1 (95% CI 1.3-7.4). Moreover, abnormal DV as an early marker of AT shows a DR of 35.7%, an FPR of 4.3%, a PPV of 1.2%, an NPV of 99.9%, and an OR of 12.3 (95% CI 4.1-36), and the values are 33.3, 4.3, 0.97, and 99.9% and 11 (95% CI 3.2-36.9), respectively, for T21.

CONCLUSIONS

Our data supports the association between increased DVPI and CHD or AT. The sensitivity of this marker is not strong enough to be used a screening test.

Endoscopic, bioptic, and manometric findings in eosinophilic esophagitis before and after steroid therapy: a case series

BACKGROUND AND AIM

Eosinophilic esophagitis can be associated with a wide range of endoscopic patterns. The aim of the present case series report is to describe and classify endoscopic appearances before and after corticoid therapy in relation to histopathology and manometry.

PATIENTS AND METHODS

In 30 patients (m : f, 27 : 3; mean age 36.2 years) with eosinophilic esophagitis, endoscopic findings were prospectively classified according to luminal diameter and mucosal pattern. Manometric and bioptic histopathologic findings were also recorded. Endoscopy was repeated following a 3-month course of steroid therapy.

RESULTS

In total, 20 % of patients showed a concentric esophageal stricture, and in 57 % simultaneous contraction rings were visible. Mucosal alterations consisted of granular mucosa (20 %), longitudinal furrows (33 %) and transversal undulations (3 %). Lower esophageal sphincter dysfunction and distal esophageal dysfunctional manometry were seen in 73 % and 57 % of cases, respectively. Following steroids, the esophagus showed a normal caliber in 97 % of patients, and 63 % of patients had normal mucosa.

CONCLUSIONS

The most frequent findings were narrowing of the esophageal lumen, which returned to normal following steroid treatment to a larger extent than mucosal alterations.

Budesonide combined with ursodeoxycholic acid in primary biliary cirrhosis with advanced liver damage

We describe two patients with primary biliary cirrhosis who rapidly suffered progressive liver failure and developed jaundice, despite having undergone correct therapy using ursodeoxycholic acid. Both cases showed an extraordinary clinical and biochemical response 2 months after budesonide was added to standard therapy, leading to recovery of normal liver function.

Genomic affinities between maize and Zea perennis using classical and molecular cytogenetic methods (GISH-FISH)

In this study we have analysed and compared the genomic composition, meiotic behaviour, and meiotic affinities of Zea perennis and Zea mays ssp. mays. To do so we studied the parental taxa and the interspecific hybrid Zea perennis x Zea mays ssp. mays, using classical cytogenetic methods, as well as GISH and FISH. GISH enabled us to recognize the genomic source of each chromosome involved in the meiotic configurations of this hybrid, and established the genomic affinities between their parental species. The results obtained here reinforce the hypothesis of the amphiploid origin of Zea perennis and, together with previous research, indicate that the chromosomes with divergent repetitive sequences in maize and Zea luxurians could be the remnants of a relict parental genome not shared with Zea perennis.

Simple approach to prenatal diagnosis of transposition of the great arteries

OBJECTIVE

To analyze the most relevant anomalies, seen in a sequential segmental transverse views approach to imaging the fetal heart, that provide clues to the diagnosis of complete transposition of the great arteries (TGA).

METHODS

We reviewed retrospectively all the cases of isolated TGA diagnosed in our center or submitted for a second opinion through the spatio-temporal image correlation (STIC) telemedicine (TELE-STIC) program. Only transverse cardiac sweeps were obtained. Digital video clips and STIC volumes were reviewed. The abnormal features on four-chamber, five-chamber, three-vessel (3V) and three vessels and trachea (3VT) views were analyzed.

RESULTS

The study population consisted of eight fetuses with TGA with normal extracardiac anatomy. The gestational age ranged from 13 to 32 (mean, 23) weeks. The maternal age ranged from 25 to 42 (mean, 32) years. A normal four-chamber view was seen in seven cases. Only one case demonstrated a significant ventricular septal defect. At the level of the five-chamber view a straight course arterial vessel arose from the left ventricle with lateral branches in all fetuses. In the 3V view, the ascending aorta was seen reaching more anteriorly than was the pulmonary artery in six cases. At the level of the 3VT view, two vessels (transverse aortic arch and superior vena cava) rather than three were seen in all cases.

CONCLUSION

Our proposed sequential segmental approach to imaging the fetal heart apparently allows, in five-chamber and 3VT views, clear and confident signs to be detected that aid diagnosis of TGA.

The genome organization and diversification of maize and its allied species revisited: evidences from classical and FISH-GISH cytogenetic analysis

The present review summarizes our classical and molecular cytogenetic investigations in the genus Zea. The results obtained from the meiotic behavior analysis of Zea species and hybrids, confirm the amphiploid nature of all species in the genus, with a basic number of x = 5 chromosomes. All species with 2n = 20 are diploidized allotetraploids, whereas Z. perennis (2n = 40) is an allooctoploid with four genomes somewhat divergent from one another. These analyses also revealed the existence of postzygotic reproductive isolation among Zea species. Our studies using genomic in situ hybridization (GISH) provide evidence about the evolutionary relationships among maize and its allied species, and reveal remarkable genomic divergences. Particularly, knob sequences were not completely shared between taxa previously considered to be closely related. Our data strongly suggest that the teosinte Z. mays parviglumis is not the only progenitor of cultivated maize. Introgression of Tripsacum into cultivated maize cannot be discarded.

GISHGenomic in situ hybridization reveals cryptic genetic differences between maize and its putative wild progenitor Zea mays subsp. parviglumis

The aim of this paper is to test with genomic in situ hybridization the genomic affinities between maize and its putative progenitor Zea mays subsp. parviglumis. Blocking procedures were applied for the purpose of improving discrimination among chromosome regions. Unlabeled genomic DNA from Z. mays subsp. parviglumis as a blocking agent and labeled genomic DNA from maize were hybridized on maize chromosomes. On the other hand, mitotic metaphases from Z. mays subsp. parviglumis were blocked with unlabeled genomic DNA of maize and hybridized with labeled genomic DNA from Z. mays subsp. parviglumis. Both experiments showed that either maize or Z. mays subsp. parviglumis chromosomes have their own unique sequences. This means an unexpected degree of divergence if Z. mays subsp. parviglumis is the only progenitor of maize, a result that is discussed in relation to our previous genomic in situ hybridization observations and to the different scenarios proposed about the origin of maize.

Three-dimensional yolk and gestational sac volume. A prospective study of prognostic value

OBJECTIVE

To evaluate the relative prognostic value of ultrasound findings during the first-trimester scan by univariate and logistic regression analysis in a group of asymptomatic women.

STUDY DESIGN

A total of 125 asymptomatic pregnant women with a singleton conceptus, concordance between menstrual age and crown-rump length, and documented fetal activity, 25 for each gestational age between 6 and 10 weeks, were enrolled in the study and underwent a transvaginal sonographic examination. The following data were collected: yolk sac mean diameter and volume, gestational sac mean diameter and volume, fetal heart rate, maternal age, gestational age and presence of a retrochorial hematoma. The outcome variable was abortion, defined as pregnancy loss at any time up to 20 weeks' gestation. Normograms were constructed for volumes, mean diameters and fetal heart rate. Receiver-operator characteristic curves were performed in order to dichotomize maternal and gestational age. Univeriate analysis was performed by Fisher's exact test. Logistic regression was performed to test the relationship between independent variables and pregnancy outcome.

RESULTS

In univariate analysis, the variables significantly associated with spontaneous abortion were maternal age > 34 years, yolk sac volume outside the 5th to 95th percentile, gestational sac volume < the 5th percentile and fetal heart rate outside the 5th to 95th percentile. In regression analysis only maternal age > 34 years, gestational sac mean diameter < 5th percentile and fetal heart rate outside the 5th to 95th percentile were significant in predicting abortion.

CONCLUSION

Our data suggest that new three-dimensional parameters are of no clinical benefit in the prediction of abortion in nonbleeding, first-trimester pregnancy, when conventional sonographic parameters are used.

Cardiac defects in chromosomally normal fetuses with increased nuchal translucency at 10-14 weeks of gestation

OBJECTIVE

To examine the prevalence, distribution and spectrum of cardiac defects in chromosomally normal fetuses with increased nuchal translucency thickness.

PATIENTS AND METHODS

During a 4-year period, targeted fetal echocardiography was used in 353 chromosomally normal fetuses with increased nuchal translucency thickness at 10-14 weeks' gestation. The cardiac scan was performed at 18-22 weeks. In the last 138 cases enrolled, an additional scan at 12-16 weeks was carried out. The follow-up included the findings at necropsy or in the pediatric examination. A complete follow-up was achieved in 97%.

RESULTS

Cardiac defects were present in 32 (9.1%) cases, increasing from 5.3% in those with a nuchal translucency thickness of > or = 95th centile (3.9 mm) to 24% when thickness > or = 6 mm (p < 0.001). In 31 cases (97%), the cardiac defect was diagnosed antenatally; in 24 cases (77%) this diagnosis was confirmed later. In the remaining seven cases, the autopsy examination was not available. A wide range of cardiac defects was observed, with the most common being atrioventricular septal defect and tricuspid atresia.

CONCLUSIONS

Euploid fetuses with increased nuchal translucency thickness have a significantly increased risk of cardiac defects. This is a marker of different types of heart anomalies and constitutes an additional indication for targeted fetal echocardiography. Most of the cardiac defects can be detected by fetal echocardiography.

References intervals for fetal biometrical parameters

OBJECTIVE

To establish normal reference intervals for biparietal diameter, head circumference, abdominal circumference, and length of femur, a cross-sectional study.

STUDY DESIGN

Five hundred singleton fetuses for each week at gestations between 23 and 41 weeks with a total of 9500 fetuses. Antenatal ultrasound measurements from all consecutive pregnant women referred to the ultrasound unit for scanning of fetal condition are prospectively entered in a data bank. For the purpose of this study, sonographic measurements were collected retrospectively and each fetus contributed just one value to the reference sample.

RESULTS

The mean curve of the four biometrical parameters varied with gestational age, with flattening of the curves at the end of gestation and increased width of normal ranges with increasing gestational age. Maximal weekly increases occurred at 24 weeks' gestation for head circumference, abdominal circumference, and length of femur and at 26 weeks' gestation for biparietal diameter. The four biometrical parameters, however, showed 50% increases in size at 33 weeks' gestation.

CONCLUSIONS

These fetal size reference intervals are clinically relevant and can be used for populations with epidemiological features and distribution of neonatal birth weights similar to our data.

Measurement of nuchal translucency as a single strategy in trisomy 21 screening: should we use any other marker?

OBJECTIVE

To evaluate the role of nuchal translucency thickness as a single marker in screening for trisomy 21 at 10-16 weeks' gestation.

METHODS

From December 1996 to October 2001, nuchal translucency was measured in 11,281 consecutive early second trimester fetuses referred to our unit for prenatal care and delivery. Scans were performed by eight experienced ultrasonographers, under strict methodological criteria.

RESULTS

Chromosomal abnormalities were found in 118 cases (52 trisomy 21). Using nuchal translucency greater than the 95th centile as a cut-off, the overall detection rate was 71.2% with a specificity of 95.4%, and a positive predictive value of 14%. In the trisomy 21 selected group, detection rate, specificity, and positive predictive value for nuchal translucency were 92.3%, 95.4%, and 8.5%, respectively. The detection rate of trisomy 21 reached 100% when nuchal translucency was measured between 10 and 14 weeks' gestation, maintaining the same specificity.

CONCLUSION

Early second trimester nuchal translucency measurement can achieve prenatal detection rates of trisomy 21 greater than 95% with a 5% false-positive rate. With a detection rate so high, the benefits of using additional markers may be less than previously considered. Although maternal age, other sonographic or Doppler markers, and maternal serum biochemistry might play a role in prenatal strategies to detect fetal chromosomal abnormalities, the high detection rate of trisomy 21 fetuses using nuchal translucency as a single parameter suggests that early nuchal translucency measurement between 10 and 14 weeks' gestation can be a simple screening strategy for this condition.

The role of ductus venosus blood flow assessment in screening for chromosomal abnormalities at 10-16 weeks of gestation

OBJECTIVE

To evaluate the role of ductus venosus blood flow assessment at 10-16 weeks' gestation in screening for chromosomal abnormalities.

METHODS

Ductus venosus blood flow was prospectively evaluated in 1371 consecutive pregnancies between 10 and 16 weeks of gestation. The pulsatility index for veins was calculated. All cases were screened for chromosomal defects combining maternal age and fetal nuchal translucency thickness.

RESULTS

A chromosomal abnormality was found in 20 cases. The overall detection rate, specificity, positive predictive value, negative predictive value and odds ratio for chromosomal abnormalities were 65%, 95.7%, 18.3%, 99.5% and 41 (95% CI 16-108), respectively, when using the 95th centile pulsatility index as a cut-off.

CONCLUSIONS

These preliminary results suggest that evaluation of the ductus venosus pulsatility index at 10-16 weeks' gestation is a useful second-line screening test for chromosomal defects. A combination of nuchal translucency measurement and ductus venosus assessment might increase specificity while maintaining an optimal detection rate for chromosomal abnormalities. Such a policy could identify 55% of all chromosomal abnormalities and about 69% of autosomal trisomies, reducing the need for invasive testing to less than 1%.

Selective versus non-selective laser photocoagulation of placental vessels in twin-to-twin transfusion syndrome

OBJECTIVE

We have recently described a surgical technique for the treatment of twin-to-twin transfusion syndrome (TTTS) that allows precise identification of vascular anastomoses (selective laser photocoagulation of communicating vessels, or S-LPCV). The purpose of this study was to compare S-LPCV with the previous non-selective technique (NS-LPCV) that targeted all vessels crossing the dividing membrane.

MATERIALS AND METHODS

Patients with TTTS were treated with NS-LPCV from May 1994 to June 1997 and with S-LPCV from July 1997 to December 1999. TTTS was defined as polyhydramnios of > or = 8 cm maximum vertical pocket (MVP) in the recipient twin and oligohydramnios of < or = 2 cm MVP in the donor twin. Outcome was measured as survival per number of pregnancies and per number of fetuses together with limited morbidity data.

RESULTS

NS-LPCV was used in 18 patients and 74 were treated with S-LPCV. Three patients interrupted their pregnancies electively after surgery (S-LPCV) and were removed from further analysis. Survival of at least one fetus was higher in S-LPCV (83.1%) than in NS-LPCV (61.1%) (P = 0.04), mostly due to a lower rate of dual intra-uterine fetal demise in S-LPCV (5.6%) than in NS-LPCV (22%) (P = 0.05). There were more hydropic fetuses in the NS-LPCV group (27%) than in the S-LPCV group (5.4%), but this difference did not account for the results. There was no difference in the survival per number of fetuses between the two groups.

CONCLUSIONS

S-LPCV represents an important evolution in the surgical treatment of TTTS. The use of this technique by all centers should allow better comparison of fetal survival and morbidity rates. S-LPCV should be the standard technique in trials comparing amniocentesis versus laser for the treatment of severe TTTS.

Genomic affinities of Zea luxurians, Z. diploperennis, and Z. perennis: Meiotic behavior of their F1 hybrids and genomic in situ hybridization (GISH)

Since 1987 cytological evidence has arisen in our laboratory, pointing to x = 5 as the original basic chromosome number of maize and its related wild species. This paper deals with the analysis of the meiotic behavior of F1 hybrids Zea luxurians × Z. diploperennis (2n = 20) and Z. luxurians × Z. perennis (2n = 30). In the first hybrid the most frequent configuration was 8ll + 4l and in the latter was 5lll + 5ll + 5l. Applying GISH (genomic in situ hybridization) to mitotic chromosomes of Z. luxurians we found that DAPI (4', 6-diamidino-2-phenylindole) positive bands located in all telomeric regions of this species did not hybridize with either Z. perennis or Z. diploperennis genomic probe. Therefore, Z. luxurians has a repetitive sequence that can be used in fluorescent staining to identify its chromosomes. When GISH was employed on metaphase I of the 2n = 30 hybrid, all the univalents showed distinctive telomeres of Z. luxurians, while the bivalents did not present any signal. These findings show that the formation of bivalent-univalent configurations is not a random event. The bivalents tend to be spatially separated and are very often observed forming an independent group of 5II. Finally, trivalents were composed by one chromosome labeled in its telomeric regions, and two smaller and unlabeled ones. The use of chromosome markers of Z. luxurians demonstrated to be a good step forward in interpreting the nature of meiotic configurations in 2n = 30 Zea spp. hybrids. They can help to clarify the relationship between genomes and provide a useful addition to the taxonomic classification in the genus Zea.Key Words: Zea hybrids, evolution, cytogenetics, repetitive sequences, heterochromatic knobs.

Genomic in situ hybridization (GISH) of Tripsacum dactyloides and Zea mays ssp. mays with B chromosomes

Genomic affinities between Tripsacum dactyloides (2n = 72) and Zea mays ssp. mays (2n = 20 + 5 B) were analyzed through GISH (genomic in situ hybridization) to ascertain the degree of chromosome homology between the two genera. Mitotic cells of T. dactyloides were simultaneously probed with total genomic DNA from Z. mays ssp .mays (2n = 20) and with rDNA (pTA71). A disperse pattern of hybridization signal among all 72 chromosomes, corresponding to maize total DNA, and six strong fluorescent signals due to the rDNA probe hybridizing on 3 chromosome pairs of T. dactyloides were observed. Mitotic chromosomes from Z. mays ssp. mays (2n = 20 + 5 B) were hybridized with a maize line that lacked B chromosomes and knobs and with total DNA from T. dactyloides. The knobless line of maize hybridized intensely on all chromosomes except for some regions where the probe bound less. Tripsacum dactyloides bound intensely on one terminal region of each B chromosome and to some regions of chromosome pairs 2, 6, and 8. These regions are DAPI positive and coincide with regions that displayed lower affinity with the probe from the knobless maize line. The possible significance of these results is discussed briefly.Key words: Tripsacum dactyloides, Zea mays ssp. mays, maize B chromosomes, genomic in situ hybridization, GISH.

[Gastrointestinal anisakiasis. Seven cases in three months]

Human anisakiasis or anisakidosis is an unusual parasitation. During the autumn of 1996 seven patients came to our Hospital for such a condition. Five of these patients had the parasites in the gastroduodenal area (1 in the gastric body, 3 in the antrum and 1 in the duodenal bulb, this one with two parasites). Four out of the five patients consulted us for intense epigastric pain; only one developed a cutaneous rash. The fifth patient was diagnosed unexpectedly during an endoscopy appointment. Eosinophilia was detected in none. All the parasites were extracted endoscopically and identified as belonging to the Anisakis genera. Excepting for the patient with no complaint, the other four showed adhered larvas to mucosa. The two other patients were operated because of acute abdominal pain. At laparotomy an ileitis was seen and then resected. Under microscopic examination both ileon were found to be edematous and infiltrated by eosinophils. Anisakis larvae were observed in the submucosa of one of the removed intestines. The other patient was diagnosed after an immunologic study consisting of radioimmunoassay and Western Blot. Five of the seven patients (71%) acquired the parasites after consumption of anchovies with vinegar.

Prenatal diagnosis of isolated hypospadias

Ten cases of prenatal diagnosis of isolated hypospadias are presented, six of them in the second trimester. The echographical basis for the suspected diagnosis of hypospadias are: anomalous distal morphology of the penis, small lateral folds (dermal remains of the prepuce), small penis with ventral incurving and anomalous urinary stream. The embryogenesis and the clinical utility of prenatal study of the genitals of the fetus, not only to determine the sex, but also to detect anomalies, are discussed.

Prenatal diagnosis of testicular torsion

A case of the prenatal diagnosis of testicular torsion at 39 weeks' gestation is presented. The affected testicle was observed as a small rounded area of hypoechogenicity with a peripheral echogenic ring without hydrocele. The appearance was suggestive of the chronic phase of testicular torsion. The neonatal genital exploration confirmed the diagnosis.

Early detection of reversed diastolic umbilical flow: should we offer karyotyping?

In normal pregnancy, end-diastolic flow appears in the umbilical artery around the 13th week of gestation, with a velocity which increases progressively with advancing gestation. The detection of reversed flow in the umbilical artery, the highest expression of an increase in placental vascular resistance, is extremely uncommon in the first half of gestation and, in three of the four cases reported in the literature, there were chromosomal abnormalities. We report a new case of reversed end-diastolic flow in the umbilical artery in a 13-week fetus with increased nuchal translucency thickness, megacystis and tachycardia. Cytogenetic analysis of chorionic villi and amniocytes revealed trisomy 13. The findings provide further evidence for a possible association between reversed end-diastolic flow in the umbilical artery and chromosomal abnormalities. However, the effectiveness of this potential marker in an unselected population requires further evaluation.

[Complete congenital atrioventricular block. Prenatal diagnosis and perinatal management]

OBJECTIVE

To describe our experience in prenatal diagnosis and perinatal management of congenital atrioventricular heart block, as well as pacemaker treatment in the neonate.

MATERIAL AND METHODS

A total of 13 fetuses are included. The diagnosis of atrioventricular dissociation was established by Doppler heart rate sample in the right atrium to show the atrial activity while the sample in the Aorta reflected the ventricular heart rate. Gestational age at diagnosis, ventricular heart rates, autoimmune maternal pathology, maternal blood tests for autoantibodies antiRo+, congenital structural heart disease, fetal hydrops, maternal medical treatment, perinatal results and pacemaker neonatal implantation are described.

RESULTS

Gestational age at diagnosis ranged between 22 and 32 (mean 27.6) weeks. Ventricular heart rates ranged between 32 to 80 (mean 54) beats/min. AntiRo+ antibodies were detected in 5 mothers, and clinical systemic lupus erythematosus was found in only one. Four had congenital heart disease (2 ventricular inversion and corrected TGA, 1 complete atrio-ventricular canal and 1 tricuspid atresia). Signs of heart failure and hydrops were detected in 9 fetuses. Treatment with beta-metasona and ritodrine was administered to 7 mothers when the ventricular heart rate dropped below 60 beats/min. Intrauterine fetal death occurred in 3 fetuses with structural congenital heart disease and hydrops. Delivery was performed by cesarean section in 8 preterm fetuses (one them a twins), 3 spontaneous deliveries at term and 3 stillbirth. Postnatal pacemaker implantation was carried out in 9 newborns (3 cases with unicameral temporal right ventricle electrode and 6 cases with permanent bicameral electrodes implanted through the subclavian vein and DDD pacemaker). Follow-up of the bicameral pacemaker group was satisfactory.

CONCLUSION

Persistent fetal bradycardia is the first sign to diagnose prenatal complete atrioventricular heart block. Echocardiography asses fetal haemodynamic status and may detect signs of fetal deterioration. Hydrops and further drop in the ventricular heart rate warrant urgent cesarean section and pacemaker management of the newborn.

Use of interferon-alpha in laryngeal papillomatosis: eight years of the Cuban national programme

Laryngeal papillomatosis is one of the first diseases where interferon (IFN) was found to be effective. In 1983, a programme for the treatment of all such cases started in Cuba. Up to December 1991, 125 patients (92 children, 33 adults) have been treated: 102 with leucocyte IFN-alpha, 12 with recombinant IFN-alpha-2b, and 11 have received both preparations. Case management consisted of surgical removal of the lesions followed by an IFN schedule starting with 10(5) IU/kg of weight in children or 6 x 10(6) IU in adults, i.m. daily. The dose was progressively reduced, as long as no relapses occurred. At the end of the one-year schedule the doses were reduced to 5 x 10(4) IU/kg in children or 3 x 10(6) IU in adults, weekly. If there was a relapse, it was removed surgically and the patient returned to a higher dose level. Most cases (89; 71 per cent) have not relapsed after the treatment; 60 of them have been followed for more than three years. In those with relapses, the frequency of recurrence decreased in all but four patients. The treatment seemed to be more effective if initiated less than three months after the disease onset. The tracheostomy could be removed in five out of seven patients who needed it before the IFN treatment and was necessary in only three new cases during IFN treatment. In two of these, decannulation was possible later on. In a total of 14 patients relapses persisted after several cycles of IFN treatment. They were considered resistant to such treatment. No severe side effects were reported. The most frequent ones were fever, drowsiness, increased bronchial secretion, chills and headache. The establishment of this programme has maintained the disease under control in Cuba.

Reversed end-diastolic umbilical artery velocity in two cases of trisomy 18 at 10 weeks' gestation

Doppler velocimetry of the umbilical artery was carried out during routine ultrasound examinations performed immediately before either chorionic villus sampling (n = 383) or genetic amniocentesis (n = 649) in 1032 women referred for prenatal diagnosis at our institution, between 10 and 18 weeks of gestation. Reversed end-diastolic flow was detected in only two cases (0.19%), both of which were affected by trisomy 18. The diagnosis was made at 10 weeks' gestation and, to our knowledge, these are the earliest records of this pathological Doppler pattern. Although a possible relationship with early abnormal placentation remains to be established, the finding of reversed end-diastolic velocities in the umbilical artery in the first trimester of pregnancy may be an early sign of karyotype abnormality.

First-trimester biochemical screening for Down syndrome with the use of PAPP-A, AFP, and beta-hCG

Biochemical screening for Down syndrome (DS) is well established in the second trimester of pregnancy, but there is little information available on its value in the first trimester. This study describes our preliminary results with biochemical screening for DS in the first trimester of pregnancy in order to evaluate its efficacy at this time. Our study population, including 19 DS pregnancies, was evaluated using maternal serum levels of alpha-fetoprotein (AFP), beta-human chorionic gonadotropin (beta-hCG), and pregnancy-associated plasma protein A (PAPP-A). At a false positive rate (FPR) of 5 per cent, the detection rate (DR) for DS is 9 per cent for beta-hCG, 18 per cent for AFP, and 66 per cent for PAPP-A when considering these parameters individually. With different combinations of the analytes, the best detection rates are obtained with the association of PAPP-A and AFP (85 and 82 per cent DR for a 10 and 5 per cent FPR, respectively). Our data support the value of first-trimester biochemical screening for DS and that of PAPP-A as a single marker.