Impact of Preoperative Cervical Length on Pregnancy Outcome in Twin-Twin Transfusion Syndrome.

OBJECTIVE: To evaluate the impact of preoperative cervical length on pregnancy outcome in monochorionic diamniotic twin pregnancies complicated by twin-twin transfusion syndrome that underwent laser surgery or cord occlusion. MATERIALS AND METHODS: Retrospective study of 330 patients stratified by preoperative cervical length (≥25 mm, 16-24 mm,≤15 mm). Maternal characteristics, operative data, and pregnancy outcomes were compared between the cervical length groups as well as between the subgroups of patients with a cervical length≤15 mm according to management (expectant vs. cerclage). RESULTS: A preoperative cervical length≥25 mm was observed in 82% (n=271) of cases, 16-24 mm in 9% (n=29), and≤15 mm in 9% (n=30). Patients with a preoperative cervical length≤15 mm showed shorter median procedure-to-delivery interval (5.5 weeks vs. 11.6 (16-24 mm) vs. 13.0 (≥25 mm); p<0.001); lower median gestational age at delivery (29.5 weeks vs. 34.3 (16-24 mm) vs. 33.4 (≥25 mm); p<0.001); higher rate of preterm delivery<32 weeks (78 vs. 20% (16-24 mm) vs. 31% (≥25 mm); p<0.001); and lower neonatal survival rate of at least one twin (70 vs. 88% (16-24 mm) vs. 93% (≥25 mm); p<0.001). Outcome of patients with a preoperative cervical length≤15 mm was similar regardless of management. CONCLUSION: Monochorionic diamniotic twin pregnancies complicated by twin-twin transfusion syndrome with a preoperative cervical length≤15 mm showed a higher rate of preterm delivery<32 weeks and lower neonatal survival. The role of a cervical cerclage remains unclear.

The heart after surviving twin-to-twin transfusion syndrome.

BACKGROUND: The persistent changes in cardiac structure and function in children who survived twin-to-twin transfusion syndrome remain a matter of concern and controversy. Current fetal echocardiographic parameters and their postnatal evolution can help improve our understanding of the subject. OBJECTIVE: To describe the echocardiographic changes of monochorionic fetuses affected by twin-to-twin transfusion syndrome, the recipient and the donor, before and after laser photocoagulation and to determine their evolution in the third trimester and during their first year of life. STUDY DESIGN: An observational study was conducted including 55 uncomplicated monochorionic diamniotic twins and 78 pairs with twin-to-twin transfusion syndrome, 44 stage I-II and 34 stage III-IV, prospectively enrolled from 2015 until 2018. Comprehensive echocardiography was performed at 4 time periods: before laser photocoagulation, at 24 to 72 hours after surgery, at 28 to 30 weeks of gestation, and at 6 to 12 months after birth. Echocardiographic parameters were transformed to z-scores or indexed for heart area, estimated fetal weight, or body mass surface. RESULTS: At diagnosis, recipients in all stages presented larger hearts (cardiothoracic ratio z-score: 2.77 [0.8] vs controls: -0.03 [0.5]; P<.001) and signs of ventricular hypertrophy (left end-diastolic ventricle wall thickness: 2.68 [0.7] vs controls -0.03 [0.7]; P<.001), along with systolic (cardiac index recipients: 317 [114] mL/min/kg vs controls: 400 [120] mL/min/kg, P<.001) and diastolic impairment (isovolumetric relaxation time z-score: 2.76 [0.6] vs controls: 0.05 [0.6]; P<.001). Donors presented smaller ventricular areas and diameters when compared with controls (left end-diastolic ventricle area z-score: -1.48 [1] vs 0.03 [0.9]; P<.001), along with decreased longitudinal motion (tricuspid annular plane systolic excursion z-score: -0.9 [1] vs controls -0.04 [1]; P<.001) and shorter ejection time z-score (-1.5 [0.7] vs controls: 0.0 [0.7]; P<.001). After surgery, an improvement in functional parameters was observed in both fetuses, whereas most morphometric changes prevailed in donors and recipients in the prenatal period. Postnatally, cardiac remodeling persisted in recipients (left relative wall thickness: 0.34 [0.02] vs controls: 0.30 [0.02]; P<.001), whereas donors mainly presented a decreased longitudinal motion in infancy (tricuspid annular plane systolic excursion z-score: -0.72 [0.7] vs controls: 0.23 [0.9]; P<.05). CONCLUSION: Cardiac remodeling is present in both fetuses at the twin-to-twin transfusion syndrome diagnosis, whereas diastolic dysfunction is only significant in the recipient. Fetal therapy improves most echocardiographic parameters, although postnatally, the echocardiographic changes persist in both fetuses.

Feasibility of 4D-Spatio Temporal Image Correlation (STIC) in the Comprehensive Assessment of the Fetal Heart Using FetalHQ®.

Fetal Heart Quantification (FetalHQ®) is a novel speckle tracking software that permits the study of global and regional ventricular shape and function from a 2D four-chamber-view loop. The 4D-Spatio Temporal Image Correlation (STIC) modality enables the offline analysis of optimized and perfectly aligned cardiac planes. We aimed to evaluate the feasibility and reproducibility of 4D-STIC speckle tracking echocardiography (STE) using FetalHQ® and to compare it to 2D STE. We conducted a prospective study including 31 low-risk singleton pregnancies between 20 and 40 weeks of gestation. Four-chamber view volumes and 2D clips were acquired with an apex pointing at 45° and with a frame rate higher than 60 Hz. Morphometric and functional echocardiography was performed by FetalHQ®. Intra- and interobserver reproducibility were evaluated by the intraclass correlation coefficient (ICC). Our results showed excellent reproducibility (ICC > 0.900) for morphometric evaluation (biventricular area, longitudinal and transverse diameters). Reproducibility was also good (ICC > 0.800) for functional evaluation (biventricular strain, Fractional Area Change, left ventricle volumes, ejection fraction and cardiac output). On the contrary, the study of the sphericity index and shortening fraction of the different ventricular segments showed lower reproducibility (ICC < 0.800). To conclude, 4D-STIC is feasible, reproducible and comparable to 2D echocardiography for the assessment of cardiac morphometry and function.

Perinatal outcome after selective termination in dichorionic twins discordant for congenital anomalies.

INTRODUCTION: Our objective was to evaluate the perinatal outcome of selective termination of dichorionic twin pregnancies with discordant anomalies, according to gestational age at time of procedure. MATERIAL AND METHODS: Retrospective review of 147 dichorionic twin pregnancies referred to our Fetal Medicine Unit between 2003 and 2018 for selective termination. Gestational age at delivery, fetal loss, and overall and 28-day post-delivery survival rates, were evaluated according to gestational age at time of procedure. Selective termination procedure was defined as early, intermediate, and late when performed before 18 weeks, between 18 and 23 weeks, and after 23 weeks, respectively. Kruskal-Wallis and chi-squared test were used to compare groups. RESULTS: Overall survival at 28 days post-delivery, pregnancy loss, and preterm delivery before 32 weeks of gestation rates were 93.4%, 6.9%, and 15.5%, respectively. When stratified by gestational age at procedure, intermediate selective termination was associated with a lower survival rate than early and late procedures (86% vs. 96.9% and 100%, respectively; p = 0.035), and a nonsignificant trend for higher pregnancy loss (12% vs. 3.1%). Preterm delivery before 32 weeks of gestation occurred in 27% of late procedures, which was significantly higher than in early (9.5%) and intermediate (18.2%) procedures. CONCLUSIONS: Selective termination in dichorionic twin pregnancies with discordant fetal anomaly is associated with low pregnancy loss and preterm delivery rate, primarily when performed before 18 weeks. When legally possible, late procedures can be a good alternative, particularly in those cases diagnosed beyond the 18th week of gestation.

Left myocardial performance index in monochorionic diamniotic twin pairs complicated by selective fetal growth restriction with abnormal umbilical artery Doppler.

OBJECTIVE: To evaluate left myocardial performance index (MPI) and its time intervals in monochorionic diamniotic (MCDA) twin pairs complicated by selective fetal growth restriction (sFGR) with abnormal (persistent -type II- or intermittent -type III- absent or reversed end-diastolic flow) umbilical artery Doppler. METHODS: Retrospective study including 16 MCDA twin pairs with sFGR type II, 26 MCDA twin pairs with sFGR type III and 42 gestational age-matched uncomplicated MCDA twin pairs in a single tertiary center. Left isovolumetric contraction time (ICT), ejection time (ET), and isovolumetric relaxation time (IRT) were measured and MPI calculated by conventional Doppler at diagnosis of sFGR. RESULTS: In sFGR type II, the smaller twin had shorter ET and prolonged IRT and MPI, while the larger twin showed prolonged ICT and MPI as compared to uncomplicated MCDA twins. In sFGR type III, the smaller twin had shorter ICT and ET, while the larger twin showed prolonged ICT, IRT, and MPI in comparison to controls. CONCLUSION: A differential pattern of MPI time intervals could be observed in MCDA twins with sFGR type II and III. All twins had echocardiographic signs of pressure/volume overload, except the smaller twin type III with shorter systolic times probably reflecting reduced volume load.

Prescriptive standards of echocardiographic morphometric and functional parameters in uncomplicated monochorionic diamniotic fetuses.

OBJECTIVE: To create prescriptive standards of cardiac morphometric and functional parameters in a cohort of uncomplicated monochorionic diamniotic (MCDA) twins. METHOD: Fetal echocardiography was performed in a cohort of uncomplicated monochorionic twin fetuses scanned longitudinally, including comprehensive morphometric and functional parameters, using 2-D imaging, M-mode and conventional Doppler. A multilevel polynomial hierarchical model adjusted by gestational age and estimated fetal weight was used to fit each cardiac parameter. RESULTS: The global heart dimensions including the atrial and ventricular areas, the ventricles dimensions and myocardial wall thicknesses and most of the functional parameters, such as the longitudinal myocardial motion and the biventricular cardiac output showed a positive quadratic increment throughout pregnancy. On the other hand, the left ejection fraction, shortening fraction and right fractional area change decreased with gestational age. Scatterplots for the main structural and functional parameters and ratios by gestational age, with mean, 5th, 10th, 90th, and 95th percentiles are provided. Regression equations by estimated fetal weight are also created. CONCLUSION: We provide specific comprehensive echocardiographic prescriptive standards for uncomplicated MCDA twin fetuses following current standardized methodology. The implementation of these charts will potentially help to better identify abnormal cardiovascular parameters associated to monochorionic complications.

Uncomplicated Monochorionic Twins: Two Normal Hearts Sharing One Placenta.

Cardiovascular dysfunction has been reported in complicated monochorionic diamniotic (MCDA) pregnancies; however, little is known whether hemodynamic changes occur in uncomplicated MCDA twins. A prospective observational study was conducted including 100 uncomplicated MCDA twins matched by gestational age to 200 low-risk singletons. Echocardiography was performed at 26-30 weeks gestation and cord blood B-type natriuretic peptide (BNP) was measured at delivery. In both groups, z-scores for echocardiographic parameters were within normal ranges; however the monochorionic group had larger atrial areas (mean (standard deviation) right atria-to-heart ratio: 17.0 (2) vs. 15.9 (1); p = 0.018; left atria-to-heart ratio: 17.0 (3) vs. 15.8 (2); p < 0.001) and signs of concentric hypertrophy (right relative wall thickness: 0.66 (0.12) vs. 0.56 (0.11); p < 0.001; left relative wall thickness: 0.69 (0.14) vs. 0.58 (0.12); p < 0.001). Longitudinal function was increased in twins, leading to higher tricuspid annular plane systolic excursion (6.9 mm (0.9) vs. 5.9 mm (0.7); p < 0.001) and mitral annular plane systolic excursion (4.9 mm (0.8) vs. 4.4 mm (1.1); p < 0.001. BNP levels at birth were also higher in MCDA twins (median [interquartile range]: 20.81 pg/mL [16.69-34.01] vs. 13.14 pg/mL [9.17-19.84]; p < 0.001). Thus, uncomplicated MCDA fetuses have normal cardiac shape and function, but signs of cardiac adaptation were identified by echocardiographic and biochemical parameters, when compared with singletons.

Chromosome microarray analysis should be offered to all invasive prenatal diagnostic testing following a normal rapid aneuploidy test result.

Chromosomal microarray analysis (CMA) has now replaced karyotyping in the analysis of prenatal cases with a fetal structural anomaly, whereas in those pregnancies undergoing invasive prenatal diagnosis with a normal fetal ultrasound, conventional karyotyping is still performed. The aims of this study were to establish the diagnostic yield of CMA in prenatal diagnosis, and to provide new data that might contribute to reconsider current practices. We reviewed 2905 prenatal samples with a normal rapid aneuploidy detection test referred for evaluation by CMA testing. Our study revealed pathogenic and reported susceptibility copy number variants associated with syndromic disorders in 4.8% (n = 138/2905) of cases, being 2.8% (n = 81/2905) the estimated added diagnostic value of CMA over karyotyping. Clinically significant CMA abnormality was detected in 5.4% (107/1975) of the fetuses with ultrasound anomalies and in 1.4% (5/345) of those considered as low-risk pregnancies. Our series shows that in prenatal samples, CMA increases 2-fold the diagnostic yield achieved by conventional karyotyping.

Characterizing cardiac dysfunction in fetuses with left congenital diaphragmatic hernia.

OBJECTIVE: To evaluate cardiac function by conventional echocardiography and tissue Doppler imaging in fetuses with left congenital diaphragmatic hernia (CDH). METHODS: Conventional echocardiography (myocardial performance index, ventricular filling velocities, and E/A ratios) and tissue Doppler imaging (annular myocardial peak velocities, E/E' and E'/A' ratios) in mitral, septal, and tricuspid annulus were evaluated in a cohort of 31 left-sided CDH fetuses and compared with 75 controls matched for gestational age 2:1. RESULTS: In comparison to controls, CDH fetuses had prolonged isovolumetric time periods (isovolumetric contraction time 35 ms vs 28 ms, P < .001), with higher myocardial performance index (0.49 vs 0.42, P < .001) and tricuspid E/A ratios (0.77 vs 0.72, P = .033). Longitudinal function assessed by tissue Doppler showed signs of impaired relaxation (mitral lateral A' 8.0 vs 10.1 cm/s, P < .001 and an increased mitral lateral E'/A' ratio 0.93 vs 0.78, P < .001) in the CDH fetuses as compared with controls, with preserved systolic function. CONCLUSION: Left CDH fetuses show echocardiographic signs of diastolic dysfunction, probably secondary to fetal heart compression, maintaining a preserved systolic function.

Differential Changes in Myocardial Performance Index and Its Time Intervals in Donors and Recipients of Twin-to-Twin Transfusion Syndrome before and after Laser Therapy.

OBJECTIVE: To evaluate left myocardial performance index (MPI) and time intervals in fetuses with twin-to-twin transfusion syndrome (TTTS) before and after laser surgery. METHODS: Fifty-one fetal pairs with TTTS and 47 uncomplicated monochorionic twin pairs were included. Left ventricular isovolumetric contraction time (ICT), ejection time (ET), and isovolumetric relaxation time (IRT) were measured using conventional Doppler. RESULTS: Recipients showed prolonged ICT (46 ± 12 vs. 31 ± 8 vs. 30 ± 5 ms; p < 0.001) and IRT (51 ± 9 vs. 43 ± 8 vs. 43 ± 5 ms; p < 0.001) and higher MPI (0.57 ± 0.12 vs. 0.47 ± 0.09 vs. 0.44 ± 0.05; p < 0.001) than donors and controls. Donors showed shorter ET than recipients and controls (157 ± 12 vs. 169 ± 10 vs. 168 ± 10 ms; p < 0.001) and higher MPI than controls (0.47 ± 0.09 vs. 0.44 ± 0.05; p = 0.006). Preoperative MPI changes were observed in all TTTS stages. Time intervals partially improved after surgery. CONCLUSION: Donor and recipient twins had higher MPI due to different changes in the time intervals, possibly reflecting the state of hypovolemia in the donor and hypervolemia and pressure overload in the recipient.

Gender-Specific Antenatal Growth Reference Charts in Monochorionic Twins.

OBJECTIVE: To create antenatal gender-specific reference growth charts in uncomplicated monochorionic diamniotic twins. MATERIALS AND METHODS: This is a prospective longitudinal study in which uncomplicated monochorionic (MC) twin pregnancies were included from 23 + 4 weeks of gestation onwards. Estimated fetal weight (EFW) and biometric parameters (biparietal diameter, head circumference, abdominal circumference, and femur length) were evaluated in both fetuses every 2 weeks using standardized methodology. Maternal and fetal complications were excluded. Charts were fitted for each biometric parameter and EFW in relation to gestational age and fetal gender using multilevel mixed models. RESULTS: The final analysis included a total of 456 ultrasound examinations in 62 MC twins, with a mean of 7 scans per pregnancy (range 5-8). The mean as well as 5th and 95th percentiles of each biometric parameter and EFW were adjusted in relation to gender and gestational age between 24 and 37 weeks of gestation. Male fetuses have higher reference values than females, and the disparity is larger in the upper centiles of the distribution. DISCUSSION: We provide gender-specific reference growth charts for MC twins. We suggest that these charts will improve prenatal MC twin assessment and surveillance, with a more accurate classification of normal or growth-restricted fetuses adjusted per sex.

Congenital heart block related to maternal autoantibodies: descriptive analysis of a series of 18 cases from a single center.

The objective of this study was to describe the clinical and immunological characteristics of maternal autoimmune-mediated fetal congenital heart block (CHB) in a cohort of pregnant women from an autoimmune disease pregnancy clinic. This is a retrospective observational study of all women presenting with CHB in our autoimmune disease pregnancy clinic from January 1997 to December 2014. In addition, perinatal outcome is also described. Fourteen patients accounting for 18 fetuses with CHB were identified. The median age was 32.5 years (range, 22-40). Seven (50 %) patients had Sjögren's syndrome, and the remaining seven were asymptomatic carriers of autoantibodies. All patients had anti-Ro/SSA antibodies, and 11/13 (85 %) had anti-La/SSB antibodies. The median gestational age at the time of CHB was 22 weeks (range 18-28). Complete third degree CHB was detected in 12 (67 %). Seven cases of CHB were treated with dexamethasone, two with ritodrine, and one with the association of dexamethasone, ritodrine, and terbutaline. In 9 (50 %) cases that presented with, or developed, very poor prognosis factors, such as a ventricular rate below 50-55 bpm and/or the presence of fetal hydrops, parents opted for the termination of pregnancy, after dedicated counseling. Finally, there were nine newborns (seven males [78 %]) with median age at delivery of 37 weeks (range, 32-39). A definitive epicardial pacemaker was placed in six newborns, four of them within 2 weeks of life. CHB is a severe complication related to maternal anti-Ro/SSA and anti-La/SSB antibodies. Our results confirm previous data showing that therapy is ineffective, and most of the surviving patients will require neonatal pacemaker.

Accuracy of Fetal Echocardiography in the Differential Diagnosis between Truncus Arteriosus and Pulmonary Atresia with Ventricular Septal Defect.

OBJECTIVES: To report on the accuracy of fetal echocardiography in the distinction between truncus arteriosus communis (CAT) and pulmonary atresia with ventricular septal defect (PA-VSD) and to describe the association with extracardiac and chromosomal anomalies. METHODS: This was a retrospective study on 31 fetuses with a single arterial trunk overriding a VSD with a nonidentifiable right ventricle outflow tract with anterograde flow. Data on the type of cardiac defect, gestational age, characteristics of the arterial trunk valve, presence of additional vascular, chromosomal and extracardiac abnormalities and postnatal outcome were obtained. Misdiagnosed cases were reevaluated by four-dimensional spatiotemporal image correlation (4D-STIC) echocardiography. RESULTS: The overall diagnostic accuracy was 81% and increased to 93.5% with 4D-STIC. Chromosomal and extracardiac anomalies were detected in 40 and 27%, respectively. In the PA-VSD group, patent ductus arteriosus and major aortopulmonary collateral arteries (MAPCAs) were present in 70 and 50% of the cases, respectively, coexisting in 1 of 5 cases. MAPCAs were significantly associated with a right aortic arch and with a 22q11 microdeletion in 50% of cases. CONCLUSIONS: A prenatal distinction between CAT and PA-VSD can currently be achieved in most cases. MAPCAs should be actively searched for when PA-VSD is suspected, as they are associated with a higher risk of 22q11 microdeletion and potentially complicate postnatal treatment.

Longitudinal annular displacement by M-mode (MAPSE and TAPSE) in twin-to-twin transfusion syndrome before and after laser surgery.

OBJECTIVE: To evaluate mitral and tricuspid annular plane systolic excursion (MAPSE and TAPSE) in fetuses with twin-to-twin transfusion syndrome (TTTS) before and after laser therapy. METHODS: A prospective study in 24 fetal pairs with TTTS evaluated 24 h before and within 48 h after fetoscopy and 13 gestational age-matched normal monochorionic fetal pairs. MAPSE and TAPSE were measured in an apical or basal four-chamber view by placing the M-mode cursor at the lateral valve ring. RESULTS: Mean preoperative MAPSE (controls 3.6 ± 1.3 mm vs. donors 2.7 ± 0.8 mm vs. recipients 2.8 mm ± 0.9; P < 0.001) and TAPSE (controls 4.4 ± 1.5 mm vs. donors 3.3 ± 1 mm vs. recipients 3.6 ± 1.1 mm; P < 0.001) values were significantly reduced in both TTTS fetuses. When subdividing according to TTTS stages, changes were significant in both stage I-II and III-IV subgroups, although differences were more pronounced in the latter. All observations remained unchanged 48 h post-fetoscopy. CONCLUSION: Both recipient and donor fetuses had decreased global longitudinal motion, even in early TTTS stages.

Amniocentesis: guía práctica / Amniocentesis: A practice guideline

La amniocentesis es un procedimiento de diagnóstico prenatal invasivo de segundo trimestre, descrito inicialmente en 1966 por Steele y Berg. Consiste en la introducción de una aguja espinal a través de la pared abdominal, la pared uterina y la cavidad amniótica bajo guía ecográfica continua, de forma que se pueda aspirar una muestra del líquido amniótico que envuelve el feto y que contiene células de origen fetal. La amniocentesis se realiza a partir de las 16 semanas de gestación y en el líquido amniótico se pueden realizar estudios cromosómicos, bioquímicos, moleculares o microbiológicos. El procedimiento conlleva un riesgo de pérdida fetal de aproximadamente el 0,5% cuando se realiza en el segundo trimestre, después de la fusión de la membrana amniótica con el corion, además de un riesgo menor de otras complicaciones, como la pérdida de líquido amniótico (0,3%), hemorragia placentaria, infección intraamniótica, hematoma de la pared abdominal o traumatismo fetal. A medida que la experiencia internacional se acumula, se van determinando los factores que pueden ayudar a mejorar aún más la seguridad y la facilidad técnica del procedimiento. Hemos descrito un nuevo método de aspiración para realizar la amniocentesis que emplea un Vacutainer(R) (BD Vacutainer Systems, Plymouth, Reino Unido), para obtener un vacío continuo cuando la aguja ya está insertada dentro de la cavidad amniótica, en contraste con la técnica estándar de aspiración mediante jeringa o «pistola» en que las presiones negativas son discontinuas. Sin embargo, la técnica clásica con aspiración con jeringa continua siendo válida y la más utilizada. Basados en la experiencia de 30 años y en el volumen de procedimientos realizados en nuestro centro (más de 20.000 procedimientos invasivos realizados), junto con una revisión de la bibliografía publicada hasta la fecha, hemos planteado una guía práctica actualizada para la realización de la amniocentesis (AU)

Amniocentesis, initially described by Steele and Borg in 1966, is an invasive prenatal diagnostic procedure used in the second trimester. It consists of inserting an ultrasound-guided spinal needle through the abdominal and uterine wall and into the amniotic cavity in order that a sample of the amniotic fluid that surrounds the foetus, and contains cells of foetal origin, can be aspirated. Amniocentesis is performed after 16 weeks gestation, so that chromosomal, biochemical, molecular, or microbiological studies can be performed on the amniotic fluid. The procedure carries a risk of foetal loss in approximately 0.5% when it is performed in the second trimester after the fusion of the amniotic and chorionic membrane, as well as lesser risk of other complications such as, loss of amniotic fluid (0.3%), placental haemorrhage, intra-amniotic infection, abdominal wall haematoma, or foetal injury. As international experience accumulates, more factors that can help to improve the safety and ease of the procedural technique are being determined. We have described a new aspiration method to perform amniocentesis that uses a Vacutainer(R) (BD Vacutainer Systems, Plymouth, United Kingdom), to obtain a continuous vacuum when the needle is already inserted in the amniotic cavity, in contrast to the standard aspiration technique using a syringe or suction pistol where the negative pressures are discontinuous. However, the classic technique with continuous syringe aspiration continues being valid and the most used. Based on 30 years experience, and on the volume of procedures performed in our centre (more than 20,000 invasive procedures), together with an up to date literature review, we have established an updated practice guideline for performing amniocentesis (AU)

First-trimester screening for Down syndrome with ductus venosus Doppler studies in addition to nuchal translucency and serum markers.

OBJECTIVE: To estimate the improvement in screening efficiency when fetal ductus venosus Doppler studies are added to existing first-trimester Down syndrome screening protocols. METHODS: Statistical modelling was used with parameters derived from prospective ductus venosus studies and from the published literature. The pulsatility index for veins (PIV), was determined in the fetal ductus venosus for 3706 unaffected and 25 Down syndrome pregnancies at 10-14 weeks' gestation. Concurrent nuchal translucency measurement and maternal serum pregnancy associated plasma protein A and free-beta human chorionic gonadotrophin were also measured. RESULTS: The median PIV in Down syndrome was 1.70 times higher than in unaffected pregnancies (95% confidence interval 1.36-2.12). PIV levels followed an approximately log Gaussian distribution with log(10) standard deviations of 0.193 and 0.076 in Down syndrome and unaffected pregnancies. There were no statistically significant correlations between PIV and the other markers. Modelling predicts that for a fixed 5% false-positive rate, the addition of PIV to nuchal translucency alone will increase the detection rate from 76 to 85%, and combined with serum markers, from 88 to 92%. For a fixed 85% detection rate, the false-positive rate reduced from 15 to 4.8% and from 3.2 to 1.2% respectively. CONCLUSION: Ductus venosus Doppler studies can substantially improve Down syndrome screening efficiency.

Individual placental territories after selective laser photocoagulation of communicating vessels in twin-twin transfusion syndrome.

OBJECTIVE: Intrauterine fetal death of one or both twins after laser therapy (selective photocoagulation of communicating vessels) may occur, in part, from insufficient individual placental mass. The objective of this study was to assess the percentage of individual placental mass (individual placental territory) that is associated with fetal survival in twin-twin transfusion syndrome after selective photocoagulation of communicating vessels. STUDY DESIGN: Placentas from 72 patients with selective photocoagulation of communicating vessels-treated twin-twin transfusion syndrome without intrauterine fetal death and from 61 monochorionic pregnancies without twin-twin transfusion syndrome (control subjects) were assessed. The placentas were weighed fresh (total placental mass) and cut along the vascular equator, which yielded the individual placental mass and the individual placental territory. Patency of anastomoses was ruled out with air-injection. The individual fetoplacental ratio was obtained by dividing birth weight by the corresponding individual placental mass. RESULTS: The 5th percentile individual placental territory that was associated with fetal survival was 27% in control subjects and 18% in cases with twin-twin transfusion syndrome, with a minimum of 10% to 14%, respectively. There were no differences in total placental mass, individual placental mass, individual placental territory, or individual fetoplacental ratio between pregnancies with twin-twin transfusion syndrome and control subjects. However, corrected for gestational age, the birth weight of recipient and donor twins were significantly smaller than control subjects. The individual placental territory of donors was statistically smaller than that of recipients. Individual placental territories were not different within control subjects. CONCLUSION: Fetal survival typically is associated with at least 18% of individual placental territory after selective photocoagulation of communicating vessels for twin-twin transfusion syndrome, but it can occur with as little as 10% to 14% individual placental territory. Decreased birth weight of the donor twin could result from relative decreased percentage of individual placental territory or from the loss of nutrients to the recipient twin. Decreased birth weight of the recipient twin could result from partial deprivation of functional placental tissue after surgery. Our findings may contribute to the understanding of normal and pathologic monochorionic twin gestations, in the counseling of patients, and potentially to the improvement of surgical treatment of twin-twin transfusion syndrome.

Ultrasonographic diagnosis of Jarcho-Levin syndrome at 20 weeks' gestation in a fetus without previous family history.

Jarcho-Levin syndrome (JLS; spondylothoracic dysplasia) is a congenital disease characterized by multiple vertebral and rib malformations, causing a short trunk dwarfism commonly leading to respiratory insufficiency and death during the first years of life. We describe a case diagnosed during the second trimester routine ultrasound scan for screening of fetal anomalies without a previous family history. The fetus had a severe disorganization of the spine and ribs, skeletal kyphosis, with several hemivertebrae and a small thorax. All of the findings at postmortem examination confirmed the ultrasound features and were consistent with the JLS. To the best of our knowledge there is only one case reported in the literature of a prenatal diagnosis of the syndrome in a family with low risk for the condition.