K. S. Heling

Prospective detection of open spina bifida at 11–13 weeks by assessing intracranial translucency and posterior brain

We describe a case series of six fetuses with open spina bifida (OSB) from four different prenatal units, where the anomaly was detected at the routine 11–13‐week ultrasound examination. Crown–rump length ranged from 49 to 78 mm. All cases were first suspected during nuchal translucency thickness measurement in the mid‐sagittal plane of the face. OSB was lumbosacral in five fetuses and cervical in one. The intracranial translucency (IT) was obliterated in two cases, but some fluid was found in the other four cases. However, in all cases the typical landmarks of a normal posterior brain and normal IT were absent. In all six cases the ratio of brainstem diameter to brainstem–occipital bone distance was increased (≥ 1). This detection of an abnormal posterior brain led to a targeted examination and detection of the spinal lesion during the same examination in five cases, whereas in one suspicious case the patient was recalled at 17 weeks, when the abnormality was detected. Two fetuses had both multiple anomalies and trisomy 18. These prospective cases demonstrate the feasibility of using the standard mid‐sagittal plane commonly used for NT measurement to assess the IT and the posterior brain and to determine the presence of OSB during NT screening. Copyright

The thymic–thoracic ratio in fetal heart defects: a simple way to identify fetuses at high risk for microdeletion 22q11

To establish reference ranges for the fetal thymic–thoracic ratio (TT‐ratio) and to compare results with those from fetuses with congenital heart defects (CHD) with and without microdeletion 22q11 (del.22q11), a condition known to be associated with a hypoplastic thymus.

Thymic–thoracic ratio in fetuses with trisomy 21, 18 or 13

To assess thymic size expressed as the thymic–thoracic ratio (TT‐ratio) in fetuses with trisomy 21, 18 or 13.

OC29.02: Prevalence of an aberrant right subclavian artery (ARSA) in normal fetuses: a new soft marker for trisomy 21 risk assessment

and we checked this information later using Medison’s Accuvix XQ 3D eXtended Imaging (3DXI) software, for 100 selected patients. Results: The informs made by the sonographer who perform the exam were compared with the one made by another sonographer who only reviewed the 3D volume. In 98/100 patients, the results were the exactly same, and in those 2 cases in disagreement a later review confirmed the results obtained by the 3D volume analysis (a little leyomioma of 9 mm and an adnexal mass suggestive of hydrosalpinx). Conclusions: We can conclude that this new technique represents big advantages over the traditional way to perform ultrasound examination, allowing the posterior analysis of the 3D volume using differents angles and plans of view and avoiding the lost of information.

OP01.11: Prevalence of an aberrant right subclavian artery (ARSA) in fetuses with chromosomal aberrations

Objective: To evaluate the interobserver variability on the subjective assessment of the hypoplastic NB and thickened Nbr used to screen for DS after 18 weeks in women at increased risk for this aneuploidy. Methods: Images of facial profiles for true DS cases were compared to controls without DS. From Oct/03 all cases with images of facial profiles were matched to randomly selected controls having a similar initial risk for DS. The subjective assessment was for a severely hypoplastic/absent NB and if the Nbr was thickened as defined by Nbr tissue that entirely buried the underlying NB. Coded images were independently evaluated by three MFM specialists. Each image was assessed for adequacy of the profile and then for the NB and Nbr. Responses were evaluated using Cohen’s kappa. Results: 118 images were assessed, of which 31 were eliminated due to inadequate image profiles. All examiners agreed on inadequate profiles. Among the 87 cases studied, 22 had DS and 65 were normal controls.

Fetale Neurosonografie mittels 3-dimensionaler multiplanarer Sonografie

This review focuses on the examination of the fetal brain, using three-dimensional (3D) ultrasound and the multiplanar rendering mode (MPR). The routine examination of the brain is achieved with axial planes but a dedicated fetal neurosonogram requires additional coronal and sagittal views, in order to provide a complete view of the different brain structures. Because these planes are difficult to obtain under many conditions, the present paper shows how 3D MPR allows one to obtain 1 or multiple reconstructed images from a digital volume. The display can be either as orthogonal planes, tomographic planes with parallel slices or as one single plane of the region of interest, which can be selected by the examiner. This approach allows easily the demonstration of the corpus callosum, the cerebellar vermis, the three-horn view, the foetal hippocampus and other regions. In addition, early neurosonography of the developing brain from the 7th week of pregnancy onwards can be achieved.

P01.01: Aberrant right subclavian artery (ARSA) in fetuses with trisomy 21

Objective: An ARSA is diagnosed when the vessel arises separately from the aortic arch and courses behind the trachea, instead of from the brachiocephalic trunk. It is detected by applying color Doppler at the level of the three-vessel-trachea view. An ARSA is found in approx. 1.5% of the normal population and was described to be more common in fetuses with Trisomy 21. The aim of the present study was to find out the prevalence of this vascular variant in fetuses with Trisomy 21. Patients: In the four years study (2004–2008) fetuses with trisomy 21 between 11 weeks and term and a documented course of the right subclavian artery (RSA) were included in the evaluation. Results: A total of 66 fetuses could be assessed and an ARSA was found in 13 cases (19.6%). The prevalence was the same in the group undergoing 11–14 weeks screening (7/33 = 21%). Conclusions: This study confirms earlier observations on the common finding of an ARSA in fetuses with trisomy 21, but the prevalence is lower than first described. 20% prevalence in trisomy 21 fetuses versus 1,5% in the normal population results in a likelihood ratio of 13× increased risk. This sign can be added to first and second trimester genetic scan.

OC28.01: The thymic‐thoracic ratio: a simple quotient for detecting fetuses at high risk for microdeletion 22q11

Objectives: Ovarian cancer mortality remains high mainly due to late diagnosis. Since 1999 we have performed color Doppler transvaginal (CDTV) ultrasound as a form of screening for ovarian cancer. The purpose of this paper is to assess the efficiency of CDTV ultrasound to detect early stages of ovarian cancer. Methods: Screening CDTV ultrasound has been annually performed in asymptomatic women without a family history of ovarian cancer. Women with abnormal screen had repeat tests after 4–6 weeks. If the finding remitted, CDTV follow-up at one year. If the abnormality persisted, the study was completed with tumor markers, CT scan and laparoscopy. Results: A total of 184.660 screen CDTV ultrasounds were performed in 71.166 women. In 46 patients a malignant tumor was diagnosed and histologically confirmed. In eighteen of them (41%), a borderline lesion was detected. The mean age of the patients was 48 years (± 12). Thirty-four (77.3%) of these tumors were in stage I (including two cases of Fallopian tube), 3 in stage II, 7 in stage III and two were a metastatic lesion. Only 30.4% of 46 patients had increased levels of CA 125. Conclusions: Although consensus about the benefits of transvaginal ultrasound as a screening procedure is not unanimous, our data suggest that tumors detected in patients screened with transvaginal ultrasound are in earlier stages. Additional randomized studies are needed to support these preliminary findings.

OP38.07: Intracranial translucency (IT) and posterior brain at 11–14 weeks in fetuses with opened spina bifida: an update

Methods: All cases with a confirmed diagnosis of TD seen in our Units since 1995 were identified, and records reviewed to ascertain ultrasound findings and measurements. Charts of fetal size were constructed using the LMS model and compared with those used in normal pregnancies and other skeletal dysplasias. Since 2007, the Genetics Laboratory at GOSH has offered cffDNA testing for selected single gene disorders; cases referred because of suspected TD were ascertained and cffDNA results compared with postnatal diagnoses. Results: Fetal size charts derived from 39 cases demonstrated long bone length ≤ 3rd centile from 12 weeks’ gestation, with minimal growth in the 3rd trimester. Commonly reported sonographic features included bowed femora, frontal bossing, short fingers, cloverleaf skull, a small chest and polyhydramnios. Analysis of cffDNA in six cases confirmed the presence of 1948 A>G mutation in four, and 742 C>T mutation in a fifth. In the 6th case, no result could be issued because of the low concentration of cffDNA. Conclusions: A combination of ultrasound features with reference to disease-specific fetal size charts and molecular analysis of cffDNA permits accurate, non-invasive prenatal diagnosis of TD. For cases diagnosed in early pregnancy this approach may facilitate surgical intervention without compromising acquisition of the definitive diagnosis needed for genetic counselling.

P09.05: Prenatal diagnosis of a fetus with a CHARGE syndrome

the corpus callosum. Genetic amniocentesis was performed. All cells from two independent cultures showed an abnormal female karyotype with an inverted duplication of the short arm of chromosome 5 involving region 5p;13 to 5p;15.2. Parental karyotypes were normal, indicating a de novo chromosomal rearrangement. Following induction of labor at 39 weeks gestation a live female infant was delivered, birthweight 3310 g. The infant had generalized hypotonia, micrognathia, epicanthic folds, bilateral talipes, dysplastic ears and abnormal rolling eye movements. She was intermittently apneic. Active management was declined by the parents in view of the known chromosomal abnormality. The infant was discharged home and died on Day 24 of life. Trisomy of the short arm of chromosome 5 is very uncommon and to our knowledge this is the first reported case of an antenatal diagnosis of this condition. Various phenotypes have been described and depend on the region of the chromosome involved in the duplication. The critical region appears to be region 13. Infants with duplication of this region display a characteristic phenotype with generalized hypotonia, facial dysmorphism and developmental delay. Prognosis for these individuals is very poor. The antenatal diagnosis of trisomy 5p involving duplication of region 13 in this case enabled informed decision-making regarding the intrapartum and neonatal management of this infant.