S. Fernandez

Reference ranges for uterine artery mean pulsatility index at 11–41 weeks of gestation

To construct gestational age (GA)‐based reference ranges for the uterine artery (UtA) mean pulsatility index (PI) at 11–41 weeks of pregnancy.

Umbilical venous blood flow measurement: accuracy and reproducibility.

Umbilical venous blood flow could be considered a direct and physiological measurement of vascular placental function, representing the quantity of oxygen and nutrients reaching the fetus. The advent of high‐technology ultrasound and pulsed Doppler has overcome some of the limitations of early studies. Indeed, Doppler measurement of umbilical venous blood flow has been found to be accurate when compared with several gold standards for in‐vivo flow calculation. Nevertheless, small errors in volume flow components, the vessel area and the mean velocity, result in large errors in the calculation of volume flow. Therefore, technique standardization is of paramount importance. Validation studies in animal models have demonstrated accurate venous blood flow measurements by estimating the vessels cross‐sectional area from perpendicular views of longitudinal sections of free‐floating portions of the cord. On the other hand, estimation of the mean velocity from the maximum velocity, rather than using the intensity‐weighted mean velocity, is less software‐dependent and more clearly defined, yielding estimates with more predictable and systematic errors. By adhering to stringent methodological recommendations, umbilical venous blood flow calculation has moderate to good intra‐ and interobserver reproducibility. Having been found to be accurate and reproducible, further studies are required to establish the clinical value of umbilical vein flow measurement. Copyright

Middle cerebral artery pulsatility index: reliability at different sampling sites

To analyze the interobserver reliability of measurement of the middle cerebral artery (MCA) pulsatility index (PI) at two different sampling sites.

Intra-and interobserver reliability of umbilical vein blood flow

To assess the intra‐ and interobserver reliability of the umbilical vein (UV) diameter, time‐averaged maximum velocity (TAMX) and umbilical vein blood flow (BF).

Umbilical artery pulsatility index: reliability at different sampling sites.

Abstract 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.

Cervical blood perfusion assessed using power Doppler‐derived estimation of fractional moving blood volume: a reproducibility study

To evaluate the reproducibility of estimation of power Doppler‐derived fractional moving blood volume (FMBV) in the uterine cervix of women with uncomplicated pregnancies.

OP01.03: Predictiveness of umbilical vein blood flow assessment at routine third‐trimester scan for smallness‐for‐gestational age at birth

Objectives: To evaluate changes in lung and cerebral blood perfusion in fetuses with early-onset intrauterine growth restriction (IUGR) and to explore its association with the degree of placental insufficiency. Methods: Lung and cerebral tissue perfusion measured by Fractional Moving Blood Volume (FMBV) and umbilical artery Doppler (UA) pulsatility index (PI) were assessed in a cohort of 31 consecutive IUGR fetuses with abnormal UA PI (> 95th centile), matched with 31 adequate-for-gestational age (AGA) fetuses. The association between UA PI, lung and cerebral perfusion was evaluated by linear logistic regression among IUGR cases. Results: IUGR fetuses showed significantly lower lung FMBV (22.2% (SD 7.7) vs. 40.5% (SD 10.3), P < 0.001) and higher cerebral FMBV (20.1% (SD 7.9) vs. 14.3% (SD 5.2), P < 0.01) than AGA. IUGR fetuses showed a significant negative correlation between lung FMBV and cerebral FMBV (r = −0.4, P < 0.01). Similarly, UA PI showed a significant negative correlation with lung FMBV (r = −0.35, P = 0.02) and a significant positive correlation with cerebral FMBV (r = 0.46, P = 0.01). Conclusions: IUGR fetuses show decreased lung blood perfusion, which is inversely correlated with the increase in cerebral blood perfusion and in umbilical artery impedance.

Fetal Thyroid Masses and Fetal Goiter

Abstract Fetal goiter is defined as an enlargement of the thyroid gland that can be secondary to thyroid dysfunction, generally hypothyroidism. It can be originated by the passage of drugs such as propylthiouracil or methimazole administered to the mother to treat hyperthyroidism. It can also be the result of the transplacental passage of stimulating immunoglobulins or antibodies against the thyroid-stimulating hormone (TSH) receptor. The enlarged thyroid gland can potentially obstruct the fetal airway and/or esophagus and so polyhydramnios can be associated. In a case where there is a suspicion of an obstruction of the fetal upper airway, an ex utero intrapartum treatment (EXIT) should be considered for the moment of delivery. Other signs associated with fetal thyroid dysfunction can be observed such as fetal tachycardia, cardiac dysfunction, or abnormalities in skeletal ossification. In cases of fetal hypothyroidism, there is a higher risk for developmental delays. Fetal growth can also be impaired when there is fetal thyroid dysfunction. Fetal ultrasound (US) is the standard for its diagnosis, but magnetic resonance imaging (MRI) could be helpful to assess the extension of the enlarged gland. Both fetal hyperthyroidism and hypothyroidism can be treated prenatally, the former by administering antihyperthyroid drugs to the mother and the latter by administering levothyroxine intraamniotically.

OC081: Cervical blood perfusion using power Doppler ultrasound and the estimation of fractional moving blood volume (FMBV): A reproducibility study

group (n = 20) injected with 0.01 mg/ml SonoVueTM 2.0 ml/kg. One of placentas was randomly selected for examination by contrast enhanced ultrasonography. Maternal and embryonic heart rate (HR) and resistance index (RI), pulsatility index (PI), and systolicdiastolic ratio (S/D) in the embryonic middle cerebral artery (MCA), umbilical artery (UA), and uterine artery (UTA) were measured before and after administration of contrast agent or physiologic saline solution. In each group, fifteen rats were cesarean to take the placenta immediately after exam, other five did after 12 hours of exam. The ultrastructural changes of the placenta were observed by electron microscope. Results: Intravascular injection of SonoVueTM was capable of delineating the vascular architecture of the villous tree of rat. No enhancement was seen after saline solution injections. There were no significant changes of resistance index (RI), pulsatility index (PI), and systolic-diastolic ratio (S/D) in the embryonic middle cerebral artery, umbilical artery, and uterine artery after administration of contrast agent or physiologic saline solution. The maternal and embryonic heart rate significantly decreased. However, differences among three groups were not statistically significant; In low dose group, there were no obvious changes of helicine artery in rats’s placenta taken immediately and after 12 hours of examination. In high dose group, taken immediately, the helicine artery wall were uneven, there are blood platelet aggregate and accrete around the thinningz; draw it after 12 hours, the vessel wall were thickening and swell, to be missing normal architecture of the blood vessel wall, the endothelial cell exfoliate in Lumen of blood vessel, we can also see apoptotic body in it. Conclusions: Contrast-enhanced ultrasonography limpidly presents the characteristics of perfusion of placenta in a rat model and does not affect the embryonic hemodynamic parameters. Low dose contrast agent does not impact ultrastructural changes of placent. High dose contrast agent can influence on ultrastructural of helicine artery wall.

OP04.07: Diagnostic correlation between 2D and 3D ultrasound at 20–22 weeks in fetal evaluation. Preliminary results

Objectives: The aim of this study is to asses the feasibility of 3D ultrasound for fetal evaluation at 20–22 weeks. Methods: A cross-sectional study was designed in order to evaluate the correlation between 2D standard ultrasound and 3D multiplanar mode by means of a General Electric Voluson 730 Expert. 35 women were scanned at 20–22 weeks of gestation. A standard anatomical ultrasound was performed in each pacient. Also six volumes of each fetus were obtained (axial head, coronal face, chest, abdominal, upper extremities and lower extremities). Observer A analysed off line the 18 cases obtained by observer B, using 4D view program. Reversaly, observer B analysed the volumes obtained by observer A in 17 pacients. A third observer C also analysed the volumes obteined by A and B in order to evaluate the interobserver reproducibility in a second step. A check list of landmarks (31)was used to study the complete fetal anatomy in both ultrasound methods. For measurements, the intraclass correlation coefficient was calculated between both techniques. Results: While with 2D standard ultrasound 99% of landmarks were identified, it was 94% with 3D off line examination. Grouping by view regions : head and face 97%, 94% respectively; heart : fourchamber 100%, three vassels and trachea wiew 97%, outflow tracts 74%; abdominal structures 100% unless both kidneys 89%; both arms 89%, both hands 57%, both legs 97% and both feet 80%. Spine was completly seen in 85%. One choroid plexus cyst was seen in 2D/3D, one foot with equinovarus position was not satisfactory visualized using 3D and it was two cases of sex error. Intraclass correlation coefficient was almost perfect for biparietal diameter, cephalic circunference and femoral length, and very good for abdominal circunference. Conclusions: 3D ultrasound seems to allow a good anatomical assesment and yield reliable mesurements at 20–22 weeks of gestation. Hands, cardiac outflow tracts and feet are, by now, structures poorly assesed by 3D standard multiplanar mode