Altered cortical development in fetuses with isolated nonsevere ventriculomegaly assessed by neurosonography.

OBJECTIVES: To perform a comprehensive assessment of cortical development in fetuses with isolated nonsevere ventriculomegaly (INSVM) by neurosonography. METHODS: We prospectively included 40 fetuses with INSVM and 40 controls. INSVM was defined as atrial width between 10.0 and 14.9 mm without associated malformation, infection, or chromosomal abnormality. Cortical development was assessed by neurosonography at 26 and 30 weeks of gestation measuring depth of selected sulci and applying a maturation scale from 0 (no appearance) to 5 (maximally developed) of main sulci and areas. RESULTS: INSVM showed underdeveloped calcarine and parieto-occipital sulci. In addition, significant delayed maturation pattern was also observed in regions distant to ventricular system including Insula depth (controls 30.8 mm [SD 1.7] vs INSVM 31.7 mm [1.8]; P = .04), Sylvian fissure grading (>2 at 26 weeks: controls 87.5% vs INSVM 50%, P = .01), mesial area grading (>2 at 30 weeks: controls 95% vs INSVM 62.5%; P = .03), and cingulate sulcus grading (>2 at 30 weeks: controls 100% vs INSVM 80.5%; P = .01). CONCLUSIONS: Fetuses with INSVM showed underdeveloped cortical maturation including also regions, where effect of ventricular dilatation is unlikely. These results suggest that in a proportion of fetuses with INSVM, ventricular dilation might be related with altered cortical architecture.

Two-Dimensional Ultrasound Evaluation of the Fetal Cerebral Aqueduct: Improving the Antenatal Diagnosis and Counseling of Aqueductal Stenosis.

OBJECTIVE: To describe a technique for the visualization and measurement of cerebral aqueduct diameter through a 2D sagittal median plane, and to report its aspect and measurement in fetuses with aqueductal stenosis (AS). METHODS: This was a cross-sectional study of 207 morphologically normal fetuses in low-risk pregnancies between 20 and 36 weeks of gestation. The cerebral aqueduct was visualized transvaginally in a midsagittal plane, and measurements of its greatest diameter (ampulla) were taken independently by an expert and a nonexpert sonographer. In addition, the aqueduct morphology from 7 fetuses with AS and complete follow-up were compared to the reference range. RESULTS: Aqueductal measurements were obtained in 206 of 207 normal fetuses. Aqueductal growth occurred linearly with gestational age. Our method demonstrated excellent interobserver reproducibility. Among the 7 fetuses with AS, the aqueductal lumen could not be identified in 6 and had a funneling aspect in 1. DISCUSSION: Our study demonstrated that it is possible to visualize and measure the cerebral aqueduct directly through a 2D ultrasound median plane. In fetuses with severe ventriculomegaly, the morphology and width of this structure could represent a relevant tool in improving AS diagnosis, differentiating it from other causes of significant ventricular dilation that carry a different outcome.

Neurosonographic assessment of the corpus callosum as imaging biomarker of abnormal neurodevelopment in late-onset fetal growth restriction.

OBJECTIVE: To explore corpus callosum (CC) developmental differences by ultrasound in late-onset small fetuses compared with adequate for gestational age (AGA) controls. STUDY DESIGN: Ninety four small (estimated fetal weight <10th centile) and 71 AGA fetuses were included. Small fetuses were further subdivided into fetal growth restriction (IUGR, n = 64) and small for gestational age (SGA, n = 30) based on poor perinatal outcome factors, that is, birth weight <3rd centile and/or abnormal cerebroplacental ratio and/or uterine artery Doppler. The entire cohort was scanned to assess CC by transvaginal neurosonography obtaining axial, coronal and midsagittal images. CC length, thickness, total area and the areas after a subdivision in 7 portions were evaluated by semiautomatic software. Furthermore, the weekly average growth of the CC in each study group was calculated and compared. RESULTS: Small fetuses showed significantly shorter (small fetuses: 0.49 vs. AGA: 0.52; p < 0.01) and smaller CC (1.83 vs. 2.03; p < 0.01) with smaller splenium (0.47 vs. 0.55; p < 0.01) compared to controls. The CC growth rate was also reduced when compared to controls. Changes were more prominent in small fetuses with abnormal cerebroplacental Doppler suggesting fetal growth restriction. CONCLUSIONS: Neurosonographic assessment of CC showed significantly altered callosal development, suggesting in-utero brain reorganization in small fetuses. This data support the potential value of CC assessment by US to monitor brain development in fetuses at risk.

Systematic review of screening for trisomy 21 in twin pregnancies in first trimester combining nuchal translucency and biochemical markers: a meta-analysis.

AIM: This article is a systematic review of the literature to establish the detection rate and false-positive rate of the combined test for the screening of trisomy 21 in twins. MATERIAL AND METHODS: We conducted a literature search (MEDLINE, EMBASE and ScienceDirect and Cochrane) to identify studies between 1995 and 2013 that provided data on the combined test in twins. Selected studies included data on maternal age, number of fetuses affected by Down syndrome, test strategy, sensitivity and specificity of the test. RESULTS: The combined test in twins had a pooled sensitivity of 0.893 [95% confidence interval (CI) 0.797-0.947] and a pooled specificity of 0.946 (95% CI 0.933-0.957). The performance of the test was good (summary receiver operating characteristic area under the curve: 0.817). In dichorionic twins, sensitivity and specificity were 0.862 (95% CI 0.728-0.936) and 0.952 (95% CI 0.942-0.96), respectively. In monochorionic twins, the sensitivity and specificity were 0.874% (95% CI 0.526-0.977) and 0.954% (95% CI 0.943-0.963), respectively. CONCLUSIONS: The results of this meta-analysis show that the accumulative evidence on the performance of the combined test in twin pregnancies is good. Nowadays, it seems to be the best first-trimester screening test available for twin pregnancies.

Transvaginal ultrasound-guided myometrial injection of radiotracer (TUMIR): a new method for sentinel lymph node detection in endometrial cancer.

OBJECTIVE: The objective of this prospective study was to determine the feasibility, safety and performance of a new method for sentinel lymph node (SLN) detection in endometrial cancer (EC) using transvaginal ultrasound-guided myometrial injection of radiotracer (TUMIR). METHODS: From 2006 to 2011, 74 patients with high-risk EC were included in the study. Twenty-four hours before surgery 148MBq of (99m)Tc-nanocolloid (8mL) was injected into two spots in the anterior and posterior myometrium using an ultrasound-guided transvaginal puncture. SLN was localized preoperatively by lymphoscintigraphy and intraoperatively with gamma probe. After SLN biopsy the patients underwent a complete laparoscopic pelvic and paraaortic lymphadenectomy. RESULTS: The TUMIR method was successfully achieved in 67/74 patients (90.5%). SLN was identified in 55 women (74.3%). No adverse effects were observed. Pelvic drainage was observed in 87.2% of women and paraaortic SLN was identified in 45.4%, with 12.8% of the patients draining only in this area. The mean number of SLN retrieved was 2.8 per patient (range 1 to 9). Metastatic disease was found in 13 (23.6%) patients. Metastatic involvement of the paraaortic lymph nodes was observed in 4 (30.7%) cases. All were identified by TUMIR. The sensitivity and negative predictive value of SLN detected by TUMIR to detect metastasis were 92.3% (95% CI 22.9-100) and 97.7% (95% CI 82.0-100), respectively. CONCLUSIONS: TUMIR is a safe, feasible method to detect SLN in patients with EC, has a good detection rate and provides representative information of the lymphatic drainage of EC.

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.

Longitudinal brain perfusion changes in near-term small-for-gestational-age fetuses as measured by spectral Doppler indices or by fractional moving blood volume.

OBJECTIVE: The objective of this study was to compare the temporal sequence of fetal brain hemodynamic changes in near-term small-for-gestational-age fetuses as measured by spectral Doppler indices or by fractional moving blood volume. STUDY DESIGN: Cerebral tissue perfusion measured by fractional moving blood volume, cerebroplacental ratio, anterior cerebral artery, and middle cerebral artery pulsatility indices were weekly performed in a cohort of singleton consecutive small-for-gestational-age fetuses with normal umbilical artery delivered after 37 weeks of gestation. RESULTS: A total of 307 scans were performed on 110 small-for-gestational-age fetuses. Mean gestational age at diagnosis and at delivery was 35.7 and 38.6 weeks, respectively. The proportion of fetuses with abnormal fractional moving blood volume, cerebroplacental ratio, anterior cerebral artery-pulsatility index, and middle cerebral artery-pulsatility index values was 31.3%, 16.8%, 17.2%, and 10.8% at 37 weeks of gestation and 42.7%, 23.6%, 20.9%, and 16.4% before delivery. CONCLUSION: The presence of brain redistribution in small-for-gestational-age fetuses was detected earlier and in a higher proportion of fetuses using cerebral tissue perfusion rather than spectral Doppler indices.

Small-for-gestational-age fetuses with normal umbilical artery Doppler have suboptimal perinatal and neurodevelopmental outcome.

OBJECTIVE: To evaluate the perinatal and neurodevelopmental outcome of small-for-gestational-age fetuses with normal umbilical artery Doppler managed expectantly during pregnancy and delivery. STUDY DESIGN: Perinatal and neurodevelopmental outcome was assessed from a cohort of singleton small-for-gestational-age fetuses with normal umbilical artery Doppler and normally grown controls matched by gestational age at delivery, parity and parental socio-economic level. Neurodevelopmental outcome was prospectively evaluated by means of the 24-month Age&Stage Questionnaire (ASQ). RESULTS: A total of 129 small-for-gestational-age fetuses and 259 controls were included. Small-for-gestational-age fetuses had a higher risk for neonatal intensive care unit admission (15.5% versus 3.9%; p<0.001) and significant neonatal morbidity (2.3% versus 0%; p=0.04) than controls. At 24-months, these fetuses showed significantly lower neurodevelopmental centile in the problem solving (42.8 versus 52.1; p=0.001) and personal-social (44.4 versus 54.6; p<0.001) areas than controls. CONCLUSION: Perinatal and neurodevelopmental outcome in small-for-gestational-age fetuses with normal umbilical artery Doppler is suboptimal, which may challenge the role of umbilical artery Doppler to discriminate between normal-SGA and growth-restricted fetuses.

Ultrasonography as a predictor of embryo implantation after in vitro fertilization: a controlled study.

OBJECTIVE: To investigate the predictive value of ultrasonographic parameters as prognostic indicators of implantation after IVF when measured on the day of embryo transfer. DESIGN: Comparative, observational study. SETTING: University teaching hospital. PATIENT(S): Two hundred eighty patients undergoing IVF. INTERVENTION(S): Ovarian stimulation, IVF. MAIN OUTCOME MEASURE(S): Variables related to patients' clinical characteristics, treatment characteristics, ovarian response, ovum retrieval, outcome of IVF and ICSI, embryo transfer, ultrasonographic and Doppler endometrial measurements, and uterine blood flow that have been proposed as potential predictive factors of implantation. All transvaginal ultrasonographic assessments were performed on the day of embryo transfer. RESULT(S): Among 240 patients finally evaluable, 67 (group 1) became pregnant after IVF, and 173 (group 2) failed to conceive. The 111 nonpregnant patients who had the same embryo score per replacement (group 3) as did patients in group 1 were selected for comparison purposes. The only significant differences between groups 1 and 3 were the type A endometrium and the absence of a protodiastolic notch in the uterine arteries, both of which were more frequently found in group 1. However, a considerable overlap existed between conception and nonconception cycles regarding both variables. CONCLUSION(S): Ultrasonographic parameters as predictors of implantation in assisted reproduction have a limited value in the clinical setting.

Cardiac function monitoring of fetuses with growth restriction.

OBJECTIVE: To describe the time sequence of changes in cardiac function in intrauterine growth restriction. STUDY DESIGN: This was a prospective longitudinal study on 22 singleton pregnancies with growth-restricted fetuses. Pulsatility indices of fetal arterial and venous Doppler waveforms, systolic peak velocity in the aorta and pulmonary artery, right and left ventricular shortening fraction and atrioventricular flow E/A ratio were assessed at each monitoring session. Logistic regression was used for modeling the probability of abnormality of a variable in relation to the time interval before delivery. Trends over time were analyzed by Mann-Withney U-test. RESULTS: Umbilical artery pulsatility index was the first variable to become abnormal, followed by the middle cerebral artery, right diastolic indices (right E/A, ductus venosus), right systolic indices and, finally, both diastolic and systolic left cardiac indices. CONCLUSION: We have found an earlier and more pronounced right than left and diastolic than systolic fetal cardiac function deterioration in growth restricted fetuses monitored longitudinally.

Meningioangiomatosis in a second trimester fetus.

We describe to our knowledge the first case of meningioangiomatosis identified in a second trimester fetus. A 30-year-old pregnant woman was attended at our hospital for a second-trimester ultrasound screening scan. With a diagnosis of partial agenesis of the corpus callosum, the parents requested termination of the pregnancy. At autopsy, frontal serial sections of the fetal brain disclosed a short corpus callosum that lacked the posterior splenium, confirming the sonographic diagnosis. At close inspection, a slight bilateral hardening of both medial aspects of the frontal lobes and anterior genu of the corpus callosum was found associated with meningeal adhesion between both frontal lobes. Microscopically, cerebral cortex and corpus callosum were permeated by intersecting bundles of spindle cells with eosinophilic cytoplasm and bland, round nuclei, with a fibroblast or meningothelial-like appearance surrounding abundant blood vessels, consistent with the diagnosis of meningioangiomatosis. According to this finding, meningioangiomatosis must be included in the differential diagnosis of meningocortical fetal lesions.

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.

Perinatal echocardiography: protocols for evaluating the fetal and neonatal heart.

This Protocol for Evaluating the Fetal and Neonatal Heart details the indications, views, and measurements to be obtained for both (1) the basic screening examination of the fetal heart (a necessary component of all complete fetal anatomy evaluations) and the specialty study called (2) echocardiography as applied to either the fetus or neonate, using 2D and Doppler ultrasound. While the purpose of the screening study is to detect or exclude the possibility of a cardiac abnormality, echocardiography attempts to diagnose the specific anatomic and physiologic disruption. Also emphasized is the value of a collaborative team approach to management of the fetus and its parents when a cardiovascular anomaly is present, in an effort to achieve a smoother transition from fetus to neonate across the continuum of perinatal care.

Intra- and interobserver reliability of umbilical vein blood flow.

OBJECTIVES: To assess the intra- and interobserver reliability of the umbilical vein (UV) diameter, time-averaged maximum velocity (TAMX) and umbilical vein blood flow (BF). METHODS: Sixty-three consecutive singleton pregnancies between 24 and 42 weeks were evaluated by two independent operators. UV diameter and TAMX were measured. UV flow was calculated as UV area x 60 x TAMX x 0.5. Reliability analyses were performed by means of the intraclass correlation coefficient (ICC) for agreement. Differences between and within observers were explored and agreement limits calculated by means of the Bland-Altman test. RESULTS: Satisfactory Doppler parameters were successfully obtained from all fetuses. The intraobserver ICCs for UV diameter, TAMX, and BF were 0.7, 0.59, and 0.55, respectively, whereas the interobserver ICCs were 0.65, 0.46, and 0.60, respectively. The 95% confidence intervals of the intraobserver differences were (+0.15, -0.14), (+8.0, -7.9), and (+150, -138.7), respectively. The 95% confidence intervals of the interobserver differences were (+0.16, -0.16), (+8.5, -8.2), and (+138.8, -141.9), respectively. CONCLUSIONS: Noninvasive Doppler calculation of umbilical vein blood flow and its components are reliable enough for clinical use.

False positives in the prenatal ultrasound screening of fetal structural anomalies.

OBJECTIVE: To describe the false-positive diagnoses of prenatal ultrasound screening of fetal structural anomalies. METHODS: Pregnancies with fetal structural anomalies either detected prenatally in our center or referred to us, were registered, evaluated, and followed-up prospectively by a multidisciplinary Congenital Defects Committee. After postnatal follow-up was completed, cases were assigned as true positives, false positives or false negatives and categorized by anatomical systems. Pregnancies referred with a nonconfirmed suspicion of anomaly were not included. The false-positive diagnoses were analyzed. RESULTS: From 1994 to 2004, 903 new registry entries of fetuses structurally abnormal at ultrasound with a complete follow-up were included in the Committee database. There were 76 false positives, accounting for 9.3% of all the prenatally established diagnoses. The urinary tract anomalies were the most frequent false-positive diagnoses found (n = 25; accounting for 8.7% of the urinary tract defects), but the genital anomalies showed the higher rate of no confirmation (n = 5; 15.2%). The specific anomalies most commonly not confirmed were renal pyelectasis (n = 9), cerebral ventriculomegaly (n = 9), abdominal cysts (n = 7) and short limbs (n = 7). CONCLUSION: Several prenatally diagnosed anomalies would benefit from prudent counseling, because they may be normal variants or transient findings.

Umbilical artery pulsatility index: reliability at different sampling sites.

OBJECTIVES: To analyse the inter-observer and inter-artery reliability of the umbilical artery (UA) pulsatility index (PI) at different sampling sites. METHODS: One hundred consecutive singleton pregnancies between 24 and 40 weeks were included. The PI was calculated by two independent operators from both umbilical arteries at the placental end, at a free-floating loop and at the perivesical segment. Reliability analyses were performed between observers and between arteries at each sampling site. RESULTS: The mean percentage of PI difference between arteries was 15.2, 14.5 and 22% at the placental end, free-loop and perivesical site, respectively. The Intraclass correlation coefficients at each site were 0.51, 0.59 and 0.67, respectively. Whereas about 20% of cases showed a percentage of PI difference between arteries greater than 20% at free-loop and placental end sites, and at the perivesical site this figure was 45%. CONCLUSIONS: The perivesical sampling site for UA PI calculation is more reliable than at a free-floating loop, albeit without significance, and is significantly more reliable than at the placental end of the umbilical cord. Since discordances in PI between both arteries are more pronounced at the perivesical site, it seems mandatory to evaluate both arteries in this segment.

Umbilical artery Doppler and umbilical cord pH at birth in small-for-gestational-age fetuses: valid estimate of their relationship.

OBJECTIVE: To evaluate the relationship between umbilical artery pulsatility index and the umbilical cord pH in small-for-gestational-age fetuses. METHODS: Data were collected from all pregnancies seen in our Fetal Surveillance Unit that underwent antenatal monitoring for being small-for-gestational-age beyond 24 weeks of pregnancy. A linear regression was used to analyse the effect of the umbilical artery pulsatility index (UAPI) and umbilical artery pH at birth, assessing interaction and controlling for clinically meaningful antenatal, Doppler, biophysical and perinatal variables. RESULTS: A total of 117 pregnancies were included. According to the estimated model (which included all clinically significant confounders and statistically significant interactions), in cases with reactive cardiotography (CTG) a 1-unit increase in the UAPI resulted in a mean decrease of 0.021 (95% 0.05 to -0.005) units of umbilical artery pH at delivery. In the non-reactive CTG group a 1-unit increase in the UAPI resulted in a mean decrease of 0.02 (95% CI 0.059 to -0.019) units of umbilical artery pH at delivery. Finally, in fetuses with a pathological CTG a 1-unit increase in the UAPI resulted in a mean decrease of 0.149 (95% CI 0.107 to 0.19) units of umbilical artery pH at delivery. CONCLUSIONS: The crude effect between umbilical artery velocimetry on umbilical artery pH at birth has to be interpreted with caution, since an important part of this effect is related to other factors that confound and modify the relationship. After controlling for confounders, it was only in fetuses with pathological CTG that the effect remained statistically significant.

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.

Successful selective termination at 17 weeks' gestation in monochorionic monoamniotic twin pregnancy affected by twin-twin transfusion syndrome and discordant for hypoplastic left heart syndrome.

OBJECTIVES: To report a successful selective feticide in a complicated monochorionic monoamniotic (MCMA) pregnancy. METHODS: A case of MCMA pregnancy with severe twin-twin transfusion syndrome and discordant for hypoplastic left heart syndrome was diagnosed at 16 weeks' gestation. A complete ultrasound and fetoscopic surveillance was performed, ruling out cord entanglement and, thus, precluding the necessity of transecting the cord. RESULTS: The selective feticide was successfully performed by bipolar coagulation of the umbilical cord of the abnormal fetus under ultrasound guidance. The survivor twin developed normally during the rest of the pregnancy and was born at term. At 6 months of age, the infant was healthy. CONCLUSION: Selective feticide in complicated monoamniotic pregnancies can be safely performed. Cord entanglement can be confidently excluded by both ultrasound and fetoscopy, thus making the systematic transection of the umbilical cord unnecessary.

Tratamiento por fetoscopia de la transfusión feto-fetal: resultados en 500 casos consecutivos / Fetoscopic laser surgery for twin-to-twin transfusion syndrome: Outcome of 500 consecutive cases

Objetivos. Evaluar los resultados perinatales de 500 casos consecutivos de transfusión feto-fetal (TFF) tratados en nuestro Hospital mediante fetoscopia láser. Material y métodos. Estudio prospectivo con 500 casos de TFF grave tratadas con fetoscopia láser como primera opción. Evaluamos la supervivencia, evolución perinatal, complicaciones obstétricas y tasa de lesión neurológica a los 6 meses de vida. Resultados. La edad gestacional media al tratamiento fue 19,4 semanas (rango 15,0-31,4). La placenta fue anterior en el 48% (n=240). La tasa de conversión a oclusión de cordón fue del 1,2% (6/500). La supervivencia neonatal global fue del 74,8% (748/1.000), con un superviviente al menos en el 91,6% (458/500). La duración media del procedimiento fue de 29,4min (9-64). No se observó ningún caso de corioamnionitis o desprendimiento de placenta asociado al procedimiento. Se observó persistencia de TFF en 2 casos (0,4%) y TAPS en 8 (1,6%). Se produjo rotura prematura de membranas (RPM) antes de las 32 semanas en 32 casos (6,4%). La edad gestacional media al parto fue de 33,6 semanas (26,4-38,5), con un 92% después de las 28 semanas. El peso medio en receptores fue 1.920 g (rango 680-3.660) y en donantes 1.615 g (rango 440-2.530). La tasa de anomalías severas del neurodesarrollo fue del 6,4%. Conclusión. En una de las mayores series consecutivas de TFF en el mismo centro, los resultados se sitúan en rango alto de las series publicadas. La coagulación fetoscópica láser de las anastomosis vasculares es segura para la madre y presenta resultados consistentes en centros con experiencia(AU)

Objective. To evaluate the perinatal outcome in the 500 consecutive cases of severe twin-twin transfusion syndrome (TTTS) treated in a single centre with fetoscopic laser coagulation. Material and methods. A prospective study including 500 cases of severe TTS treated with laser therapy as a first option. Main outcome measures were survival, perinatal outcome, obstetrical complications and rate of neurological damage at 6-12 months of life. Results. Mean gestational age at therapy was 19.4 weeks (range 15.0-31.4). The placenta was anterior in 48% (n=240) of the cases. The rate of conversion to cord occlusion was 1.2% (6/500). Overall neonatal survival was 74.8% (748/1,000), with at least one survivor in 91.6% (458/500). Mean duration of surgery was 29.4min (range 9-64). There were no cases of intra- or post-operative abruptio placenta or chorioamnionitis. TTTS persisted in 2 cases (0.4%) and TAPS occurred in 8 (1.6%). Premature rupture of membranes (PROM) at <32 weeks occurred in 32 cases (6.4%). Mean gestational age at delivery was 33.6 weeks (26.4-38.5), with 92% beyond 28 weeks. Mean birth-weight was 1,920 g (range 680-3,660) in recipients and 1,615 g (range 440-2,530) in donors. Severe neurological damage was observed in 6.4%. Conclusions. In this large consecutive series of TTTS treated by fetoscopy in the same centre, results lie in the high range of those previously reported. Fetoscopic laser coagulation of the placental anastomosis is a safe therapy and offers consistent results in centres with experience(AU)