S. Boito

OP13.06: Fetal borderline cerebral lateral ventriculomegaly: a retrospective analysis of 74 cases

S. Boito1, A. Righini2, L. Ramenghi3, L. Mandia1, P. Ficarazzi1, R. Fogliani1, G. Pardi1 1Obstetrics and Gynecology Inst., IRCCS Policlinico, Mangiagalli and Regina Elena Foundation, University of Milan, Italy, 2Radiology and Neuroradiology, IRCCS Policlinico, Mangiagalli and Regina Elena Foundation, University of Milano, Italy, 3Neonatal Intensive Care Unit, IRCCS Policlinico, Mangiagalli and Regina Elena, University of Milan, Italy

OP15.01: Absolute uterine artery blood flow volume is increased in twin human pregnancies compared to singletons

Objectives: To compare (1) absolute and (2) weight-specific blood flow volume of uterine arteries (UtA) in normal twin pregnancies to normal singleton pregnancies. Methods: Twelve twin pregnancies (10 dichorionic, two monochorionic) with normal UtA PI and normal weight at birth were included. UtA diameter and time-averaged maximum velocity were obtained to calculate flow (mL/min) and UtA flow/EFW (mL/min/kg) in each UtA. UtA flow was estimated by the formula Q = hV · πD2/4; a patient-specific coefficient, h, was obtained by an ad hoc mathematical model. Total UtA flow was calculated as a sum of right and left vessel flow volume. Twins’ UtA flow was expressed per unit EFW considering the sum of the two EFWs. Twins were compared to 48 normal age-matched singletons. Results: Gestational age at exam was similar in twins and in singletons (25.9 ± 6.4 vs. 25.2 ± 6.2 weeks, NS). UtA flow (mL/min) was significantly increased in twins (509.3 ± 240.7 mL/min) compared to singletons (337.2 ± 257.0 mL/min) (P = 0.04). UtA flow (mL/min) exponentially increased along gestation in twins and in singletons. The twins’ trend was above the third interquartile range of singletons’ reference values. UtA diameter was significantly increased in twins (0.33 ± 0.07 cm) than in singletons (0.28 ± 0.05 cm), while no differences in UtA mean velocity were observed (77.5 ± 29.9 vs. 76.7 ± 29.1 cm/sec, respectively, NS). UtA flow per EFW did not differ between twins and singletons (384.4 ± 198.6 vs. 460.9 ± 302.9 mL/min/kg, respectively, NS). Conclusions: (1) UtA flow volume (mL/min) in twin pregnancies was significantly increased. This was determined by larger vessel diameter, compared to singletons. (2) Each twin proved to share an amount of UtA flow per unit estimated fetal weight not significantly different from singletons.

Estimation of fetal oxygen uptake in human term pregnancies

Objective. Umbilical oxygen (O2) uptake is a parameter of basic physiologic interest. It has been extensively studied in chronically catheterized animals but very few data have been obtained acutely in humans. Recent developments in ultrasound technology allow the estimation of umbilical venous blood flow in utero. Methods. In all, 26 normal term pregnancies were studied at the time of elective cesarean section in order to evaluate fetal O2 uptake as the product of umbilical blood flow and umbilical O2 veno-arterial difference. An ultrasound evaluation was performed within 1 h from delivery: umbilical vein area and flow velocity were recorded to calculate umbilical vein volume flow (Qumb). Blood samples from the umbilical vein (uv) and artery (ua) were obtained at the time of fetal extraction for respiratory gases and acid–base evaluation. Results. Umbilical O2 uptake was calculated as Qumb • (uv-ua)O2 content: an average value of 0.84 ± 0.40 mmol/min was obtained. Umbilical O2 uptake per kg was 0.25 ± 0.12 mmol/kg/min, significantly related to fetal O2 delivery. Conclusions. We estimated umbilical blood flow by ultrasound and we measured umbilical O2 uptake at term obtaining a value of umbilical O2 uptake/kg similar to what previously reported in human pregnancies and chronically catheterized animals.

OP01.06: Reduction of uterine artery blood flow volume is correlated to reduced fetal mass in pregnancies with abnormal uterine resistance index

Total vascular resistance (dyne s/cm5) 1623 (1287–3125) 1163 (944–1785) 0.008 Stroke volume (mL) 69 (36–81) 67 (57–86) 0.95 Cardiac output (L/min) 5.40 (4.4–7.0) 6.1 (4.0–8.1) 0.08 Ejection fraction (%) 69 (64–83) 71 (65–79) 0.59 Midwall fractional shortening (% of predicted value) 118 (94–126) 122 (106–140) 0.04 Isovolumetric relaxation time (ms) 78 (50–90) 60 (45–75) 0.006 24 h ambulatory heart rate (bpm) 74 (61–82) 79 (76–92) 0.003 24 h ambulatory systolic blood pressure (mmHg) 117 (104–136) 106 (101–121) 0.031 24 h ambulatory diastolic blood pressure (mmHg) 75 (65–88) 66 (56–73) 0.012 24 h ambulatory mean arterial pressure (mmHg) 87 (79–104) 79 (72–87) 0.016

OC250: Fetal oxygen uptake in normal and IUGR pregnancies

Objectives: To examine the relationship between smallness, assessed by customized standards, and the predictive value of a normal umbilical artery Doppler. Methods: A cohort was created of 7645 singleton pregnancies without congenital anomalies. Fetuses suspected antenatally of being small for gestational age were referred for assessment by umbilical artery Doppler. The associations with adverse outcome were assessed for small-for-gestational age babies who had normal and abnormal Doppler, compared with neonates who were not small for gestational age. Perinatal outcome indicators were collected, including fetal distress requiring Cesarean section and neonatal morbidity (neonatal intensive care > 14 days, neonatal seizures, intraventricular hemorrhage Grade III or more, periventricular leucomalacia, hypoxic–ischemic encephalopathy, or necrotizing enterocolitis). Results: Of the 369 small-for-gestational age fetuses which had been identified antenatally, 70 (19%) had an abnormal umbilical artery Doppler and the babies from these pregnancies had an elevated risk of fetal distress requiring Cesarean section (OR 5.89; CI, 2.64–11.84) and neonatal morbidity (OR 3.99; CI, 1.04–11.03). However the 299 fetuses (81%) with normal umbilical artery Doppler also had elevated risk of fetal distress (OR 4.49; CI, 2.96–6.66) and neonatal morbidity (OR 2.26; CI, 1.04–4.39). Because of the higher prevalence, many more instances of adverse outcome were attributable to this group than to the group with abnormal Dopper (fetal distress – population attributable risk (PAR): normal Doppler 8.6 vs. abnormal Doppler 2.7; neonatal morbidity – PAR: normal Doppler 4.0 vs. abnormal Doppler 2.2. Conclusions: Smallness for gestational age according to customized weight standards defines a group of pregnancies with significantly elevated risk of adverse perinatal outcome. Normal antenatal umbilical artery Doppler cannot be taken as an indicator of low risk in these pregnancies.

OP09.19: Three‐dimensional assessment of placenta volume during the first half of pregnancy

Objective: This study examines the role of virtual reality in the visualization of 3D data volume sets of ambiguous genitalia as acquired by 3D ultrasound. Methods: In 2005 in three patients referred to our department for prenatal ultrasound assessment ambiguous genitalia were diagnosed. Postpartum diagnosis was one case of Russell-Silver syndrome, one case of an XY-female with normal labia majora and an enlarged clitoris and a case with an unusual type of cloacal malformation with an enlarged clitoris, prominent preputium and single urogenital sinus. Prenatally, patients were examined by 2D and 3D ultrasound and subsequently the images obtained at 3D ultrasound were visualized in the Barco I-Space virtual reality system. Results: In these cases, prenatal diagnosis was impossible with 2D ultrasound. 3D ultrasound provided an impression of ambiguity, however this was incorrect in two cases. In the I-Space, a better impression of genital ambiguity was established. Particularly the bi-ocular depth perception provided by the I-space was useful when faced with the task of differentiating a micropenis from an enlarged clitoris. Conclusions: The presence of ambiguous genitalia in a baby post partum presents a major diagnostic dilemma that few clinicians would attempt on a purely visual basis without resorting to palpation and physical examination. Prenatal ultrasound of such a condition can at best only alert to a condition that will need further examinations post partum, thus unfortunately raising parents’ anxiety level. A 3D virtual reality technique that improves depth perception can improve visualisation of difficult anatomical structures such as ambiguous genitalia.

P07.05: Uterine artery blood flow volume growth rate in uncomplicated human pregnancies

Objective: 1) To study uterine artery (UtA) flow (ml/min) growth rate along gestation in normal human pregnancies; 2) to evaluate longitudinal changes of UtA flow expressed per unit estimated fetal weight (EFW) (ml/min/kg). Methods: A cohort of twelve singleton uneventful human pregnancies, with a normal mean UtA PI, was included in this longitudinal study. UtA was evidenced by power-Doppler mode and sampled 10–15 mm prior to bifurcation. UtA diameter was measured on a perpendicular view after removing power-Doppler. UtA PI and velocity were measured with a Doppler beam angle < 30◦. The average of three consecutive diameters and velocities was considered. UtA flow was estimated by the formula Q = hV · πD2/4; h coefficient (0.5) was obtained by an ad hoc mathematical model. UtA total flow (ml/min) (right plus left UtA flow) was then expressed per EFW (ml/min/kg). Using linear interpolation, including random effects for the intercept and the slope of gestational age for each fetus, a linear mixed effects model was fitted. Results: Forty-seven ultrasound examinations were performed. Ultrasound exams were performed at 14.3,b1.2 weeks and every 4 weeks until delivery. Each case was definitively included in the study after recording normal perinatal and neonatal outcomes. UtA total flow (ml/min) showed a significant correlation to gestational age (133.6 ml/min at 15 weeks; 415.9 ml/min at 35 weeks) (p < 0.001), with a linear increase of 14.1 ml/min per week (right UtA 5.4 vs. left UtA 8.7 ml/min per week, p NS). UtA flow per unit EFW (ml/min/kg) showed a significant reduction from 780.3 ml/min/kg at 15 weeks to 144.1 ml/min/kg at 35 weeks (reduction rate 40.3 ml/min/kg per week). Conclusions: UtA flow (ml/min) significantly increased along gestation in this longitudinal cohort of normal pregnancies. UtA flow per unit EFW (ml/min/kg) significantly decreased longitudinally, since UtA flow (ml/min) growth rate was lower than fetal weight gain rate along gestation.

P33.07: Congenital genu recurvatum with dislocation of the knees: a case report

Objectives: To report the interest of CT imaging, associated with three-dimensional ultrasonography and MRI, in a case of bladder exstrophy. Material and Methods: We compared the three imaging modalities abilities to predict the pathology of one case of proved classical bladder exstrophy. Furthermore, CT data were compared with 15 normal fetal bony pelvis at different stages of the pregnancy. Results: Three-dimensional ultrasound using surfacing mode, proved to be accurate in facial fetal abnormalities, allowed an accurate description of fetal genitalia in our case of bladder exstrophy; nevertheless, further studies are necessary to confirm these preliminary results. CT imaging in this case was the best modality to predict fetal bony pelvis; we found a wide pubic diastasis, an external rotation of iliac wings and a pubic rami opening when compared with control fetuses, as reported in previous studies for neonates and ex vivo fetuses. Conslusion: As proved for born infants and dead fetuses, CT scan can describe abnormalities of fetal bony pelvis, in utero, allowing precise and early surgery.

OP07.06: 3D ultrasound assessment of placenta volume in the first trimester in pregnancies from assisted reproduction technologies (ART)

For amniocentesis there were 202 karyotype anomalies (7.8%). 110 trisomy 13,18,21; 20 sex chromosome and 13 triploidy accounted for 71% of abnormal results. Rapid karyotype by FISH was selectively used in 580 cases (22.4%). FISH was used in 95/143 cases (66.4%) potentially diagnosable with standard FISH probes. FISH was ordered in 60% of trisomy 21 cases and 85% of trisomy 18. Long-term culture confirmed the FISH results in all cases. In 0.5% culture failed. In 0.3% there were insufficient cells for FISH. Conclusions: The selective use of rapid karyotype techniques in CVS and amniocentesis produces a high detection rate but results in a significant number of cases not identified until the long-term culture (34% of potentially detectable cases for amniocentesis). For CVS specimens, rapid diagnosis alone results in a small but significant number of discordant results.

OP13.11: Uterine artery blood flow volume: ranges in uncomplicated human pregnancies

towards term. The peak-systolic velocity increased from mean 59 to 71 cm/s during the weeks 21–31 and remained stable until term. The diastolic velocity showed a continuous increase from 31 cm/s at 21 weeks to 43 cm/s at 40 weeks. The pulsatility index for veins decreased from 0.57 at 21 weeks to 0.44 at 40 weeks. Terms for individually conditioned observations modify the reference ranges when used for serial measurements. Conclusion: The new reference ranges reflect the development of the ductus venosus blood velocities and velocity indices during the second half of pregnancy and are thus appropriate for the serial measurements required when monitoring growth-restricted fetuses.