Biomedical subjects
Publications and source records attributed to Y Ville.
Retrospective examination of ultrasound images obtained at 12 weeks of gestation in two fetuses with spina bifida demonstrated retraction of the frontal bones, resulting in an acorn-shaped head, the cerebral peduncles appearing parallel to each other. These craniocerebral signs may improve the accuracy of first-trimester diagnosis of spina bifida by sonography.
We report a case of a 24-week-old fetus with cerebral anomalies suggestive of lobar holoprosencephaly including an unusual course of the anterior cerebral artery on Doppler examination. This abnormal trajectory of the anterior cerebral artery in holoprosencephalic brains has been described by pathologists, neurosurgeons and radiologists but our case indicates that this finding may be a useful adjunct to confirm such a difficult diagnosis prenatally.
Sexual discrepancy is reported in both 46,XY females and 46,XX males, and most diagnoses of sex reversal are made in the postpubertal period. We report three cases of sexual discrepancy, which were revealed by karyotyping following genetic amniocentesis, chorionic villus sampling and fetal blood sampling. The etiologies of 46,XX male, 45,X male and 46,XY female subjects are reviewed. When sexual discrepancy between fetal karyotype and ultrasonographic fetal phenotype is encountered, sample error and placental mosaicism should be excluded. A detailed fetal ultrasound examination should be performed to check for syndromic gender discrepancy. When repeat karyotyping is indicated, localization of the Sox related Y chromosome gene should be carried out.
We report a case of the early diagnosis of an arachnoid cyst. Transvaginal ultrasound examination of the fetal brain at 13 weeks' gestation revealed the presence of an anechoic mass above the posterior fossa. After extensive counseling and because of the uncertain prognosis of a first-trimester diagnosis of an arachnoid cyst, the parents opted for termination of pregnancy. The diagnosis was confirmed by postmortem examination.
OBJECTIVE: Intrauterine death of one twin in monochorionic pregnancies is associated with an increased mortality and morbidity of the cotwin. This is likely to occur as a consequence of acute hemodynamic changes due to feto-fetal hemorrhage at the time of death of the cotwin. We assessed the role of fetal blood sampling and intrauterine transfusion to rescue the survivor. MATERIALS AND METHODS: We managed 12 cases of single intrauterine death at between 17 and 26 weeks' gestation in monochorionic twins complicated by twin-to-twin transfusion syndrome (TTTS). All these cases had been treated either by laser therapy or by serial amniodrainage. When the demise of one twin occurred, ultrasound-guided fetal blood sampling was performed in the surviving twin using a 20-gauge needle within 24 h of death. Intrauterine transfusion was performed at the same time in cases where the survivor was anemic. All survivors were assessed in the neonatal period and at 1 year of age. RESULTS: Six of the 12 surviving fetuses were found to be anemic and underwent intrauterine transfusion. All fetuses survived the procedure. Four of these fetuses had normal neurological development at 1 year of age. Periventricular leukomalacia developed in one case and the patient underwent termination of pregnancy at 34 weeks. In one case delivery occurred at 34 weeks' gestation and the baby developed periventricular leukomalacia at 1 month of age. In all six non-anemic fetuses pediatric examination was normal at birth and at 1 year of age. CONCLUSION: Intrauterine death of one monochorionic twin in TTTS puts the survivor at high risk of intrauterine death or of developing ischemic/hypoxic lesions. Our results suggest that fetal blood sampling is a useful diagnostic tool to identify those fetuses that are not anemic and hence unlikely to be at risk of developing a cerebral lesion.
Subependymal pseudocysts are cerebral cysts found in 5% of all neonates. When they are isolated and typical, they result from persistence of the germinal matrix, have a good prognosis and regress spontaneously within a few months. However, associated anomalies are frequent and in such cases the prognosis is poor. They can be of infectious, vascular, metabolic or chromosomal origin. Subependymal pseudocysts have rarely been described in the antenatal period. We report the prenatal diagnosis of two cases of isolated pseudocysts at 32 and 23 weeks. Both ultrasonography and magnetic resonance imaging assisted in the diagnosis and there was normal postnatal outcome in both cases.
OBJECTIVE: To evaluate the learning curve and principal learning steps for a novice ultrasound operator to master the technique for measuring cervical length by transvaginal ultrasound. SUBJECTS AND METHODS: The study involved asymptomatic patients with a singleton pregnancy between 21 and 38 weeks attending for a routine ultrasound scan. Two operators new to cervical ultrasound including one with experience in transvaginal gynecological ultrasound were assessed during their training. After an initial lecture session on the technique of cervical measurement, the trainees had one or two supervised practice sessions, validated by two interobserver agreement studies with 30 patients at a time; these compared the level of agreement between trainer and trainee throughout. Five examinations were performed in the first practice session; a second session was planned if the trainee could not perform all five examinations alone satisfactorily, in agreement with four quality criteria predefined for good cervical measurements. The second session lasted until five consecutive examinations could be performed adequately without the trainer's aid. Agreement between the two operators was assessed by intraclass correlation coefficient (ICC). The ICCs were compared with Fisher's Z transformation. RESULTS: Of the 150 patients included, 2.7% gave birth before term. The trainee with no experience in transvaginal ultrasound required two practice sessions; none of the five ultrasound scans performed in the first session was correct. In the second session, 18 consecutive ultrasound examinations were necessary to obtain five consecutive adequate results. During interobserver studies with the trainer, the ICC progressed from 0.43 in the first study to 0.64 in the second and 0.77 in the third (P = 0.049 between the first and third studies). The trainee with experience in transvaginal ultrasound required only one practice session. The ICC increased from 0.73 to 0.85 in the two interobserver studies with the trainer. CONCLUSIONS: Measurement of cervical length by transvaginal ultrasound examination is a technique that can be learnt rapidly. While roughly 23 supervised ultrasound scans appear necessary for an operator with no experience in transvaginal ultrasound, substantially fewer are required for an operator already familiar with this approach for other indications.
Abnormalities of the corpus callosum are often associated with a poor prognosis due to the anatomical defect itself and associated anomalies that include malformations and inherited metabolic disorders. We report a case of the prenatal diagnosis of hypoplasia of the corpus callosum that was associated with non-ketotic hyperglycinemia. Metabolic disorders are a known association with corpus callosum abnormalities and carry a dismal prognosis. A diagnosis of non-ketotic hyperglycinemia should be considered when a fetus presents with an abnormality of the corpus callosum. A literature search reviews other inherited diseases associated with hypoplasia of the corpus callosum.
BACKGROUND: Sonographic and biochemical methods for Down's syndrome screening have developed simultaneously, but independently. As a consequence, the rate of invasive procedures for fetal karyotyping has dramatically increased and become an important public health issue which needs to be controlled. One approach is to combine sonographic and biochemical results into a single risk assessment. METHODS: In a multicentre interventional study, nuchal translucency (NT) was measured between 12(+0) and 14(+0) weeks of gestation. Maternal serum markers (MSM) were measured between 14(+1) and 17(+0) weeks of gestation. Karyotyping was advised when: (i) NT was > or =3 mm; or (ii) the MSM-related risk was > or =1 in 250 at term. Karyotyping was delayed until after a maternal blood sample had been taken. NT and MSM were expressed as multiples of the medians (MoMs), and risks were calculated and tailored to the study population. A combined risk for NT and MSM was estimated retrospectively. Costs per case diagnosed, and the cost per case averted were calculated for the three screening strategies. RESULTS: A total of 9444 women was screened. Twenty-one fetuses (0.22%) had Down's syndrome, whilst 326 women (3.4%) were lost to follow-up. Among 9118 women followed up, 5506 had both NT and MSM, 821 had only NT, and 2791 had only MSM. Median maternal age was 30.5 years. False-positive rates for NT, MSM and NT combined with MSM were 3.0, 5.8 and 0.23% respectively. The false-positive rate generated by a sequential two-stage screening was 8.6%. Detection rates of Down's syndrome were 62 and 55% for NT and MSM respectively. Seven cases with Down's syndrome (35%) had raised NT and MSM, and 17 (81%) had either raised NT, MSM, or both. For a 5% false-positive rate, detection rates were 55 and 80% for NT alone and for combined NT and MSM respectively. Ultrasound alone appears to be more cost-effective ( pound50 per case diagnosed) than both tests ( pound61 per case diagnosed). CONCLUSIONS: The study results suggest a 25% increase in the detection rate of Down's syndrome using a combination of NT measurement at 12(+0)-14(+0) weeks and MSM at 14(+1)-17(+0) weeks for a 5% false-positive rate, with modest increase in cost.
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INTRODUCTION: A case of osteogenesis imperfecta type II diagnosed in the first trimester of pregnancy. DISCUSSION: Lethal osteogenesis imperfecta is a disorder characterized by collagen abnormalities resulting in dwarfism, bone fragility and deformity leading to death in utero or in the perinatal period. Molecular and biochemical studies demonstrate that OI type II results from mutations in either COL1 A1 or COL1 A2 which encode for the chains of type I procollagen. Early diagnosis by US examination in first trimester relies on shortening and bowing of long bones, multiple fractures and hypoechogenicity of the skeleton. When ultrasound examination suspects OI type II, the diagnosis can be accomplished in the first trimester by biochemical analysis if the collagen defect is characterized. CONCLUSION: OI type II results mainly from private mutations and parental mosaicism is an important cause of recurrence making genetic counselling difficult.
Hydrocephalus-stenosis of the acqueduct of Sylvius sequence (HSAS) is characterized by hydrocephalus, macrocephaly, adducted thumbs, spasticity, agenesis of the corpus callosum and mental retardation. X-linked hydrocephalus is known to be due to mutations in the gene coding for the neural cell adhesion molecule L1 (L1-CAM) and diagnosis is made by identification of a mutation in the L1-CAM gene. Prenatal diagnosis of HSAS is usually suggested on ultrasound examination showing hydrocephalus in a male fetus associated with bilateral adducted thumbs. Mutation screening of the L1-CAM gene is indicated when neuropathological examination shows hypoplasia of the corticospinal tract associated with aqueductal stenosis. We report here two cases of HSAS diagnosed within the same family by ultrasound examination in the first trimester of pregnancy when bilateral adducted thumbs were the only early ultrasound marker.
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A case of prenatal diagnosis of an overgrowth syndrome at 30 weeks of gestation is reported. The diagnosis was suggested on the basis of increased fetal growth from 16 weeks onwards, advanced bone age, and characteristic facial features such as hypertelorism, broad forehead and small chin. The fetus presented at 12 weeks with a markedly increased nuchal translucency thickness and generalized skin edema, but normal karyotype. Serial ultrasound scans revealed brain abnormalities including mild unilateral ventriculomegaly and a cyst in the cavum septi pellucidi. The pregnancy was terminated at the parents' request at 32 weeks of gestation and postmortem examination confirmed the prenatal findings. This case demonstrates the possibility of prenatal diagnosis of early overgrowth syndromes and highlights the dilemma arising from the prenatal diagnosis of a non-lethal condition associated with an uncertain prognosis and poorly documented in utero.
OBJECTIVE: To refine the indications of bilateral hypogastric artery ligation (BHAL) and angiographic selective embolisation (ASE) in intractable obstetric haemorrhage. DESIGN: an audit study. SETTING: Tertiary care university hospital. POPULATION AND METHODS: Retrospective analysis of 61 cases of obstetric intractable post partum haemorrhage (PPH) initially managed either by hysterectomy or a conservative approach in a tertiary referral centre between 1983 and 1998. Procedures were reviewed as a primary (P) or secondary (S) attempt to arrest the haemorrhagic process. RESULTS: Ten hysterectomies (5 P, 5 S), 49 BHAL (48 P, 1 S) and 9 ASE (8 P, 1S) were successfully performed in arresting the haemorrhagic process. There were 7 maternal deaths, 5 following hysterectomy and 2 following a conservative approach. Atony of the uterus was the main cause of haemorrhage (n=21) and genital tract laceration was associated with the worst prognosis. Time-elapse between delivery and surgery appears to be the main prognostic factor. Nine patients became pregnant 1 to 4 years later following a conservative approach. CONCLUSIONS: ASE seems to be indicated in haemodynamically stable patients with birth canal trauma or uterine atony and clotting anomalies. BHAL is indicated when haemorrhage occurs after a cesarean section or when the patient is haemodynamically unstable. BHAL should be taught to Junior doctors in an attempt to decrease the number of patients transferred in tertiary referral centers for intractable PPH. This might also decrease the number of hysterectomies in intractable PPH.
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OBJECTIVES: To examine the relationship between the measurement of nuchal translucency in the first trimester and nuchal fold in the second trimester in normal pregnancy. METHODS: This was a prospective study of 592 singleton pregnancies. Fetal nuchal translucency was measured at 11-14 weeks of gestation and nuchal fold at 20-24 weeks of gestation. Linear regression models were used to assess the relationship between nuchal translucency and nuchal fold after adjustment for gestational age. RESULTS: There was no significant association between nuchal translucency and nuchal fold thickness. CONCLUSION: It is possible that measurement of nuchal translucency and nuchal fold may provide an independent contribution in screening for trisomy 21.