Objectives:The single umbilical artery (SUA) occurs between 0.2 to 1.9% of births and is associated with major malformations, aneuploidies, IUGR and perinatal death. The objective was to determine these in a large metropolitan Hospital in Santiago. Methods: Retrospective study of women that delivered in Padre Hurtado Hospital, Santiago, Chile. Data was extracted from computer ultrasound databases, delivery database and epicrisis of 13,446 newborns. Association with all perinatal complications were studied. Results: There were 84 fetuses with SUA, with an incidence of 0.62%. From these, 62 (73.8%) were isolated and 22 (26.1%) were associated with malformations or aneuploidy. The average gestational age at delivery was 36 + 4 weeks (range 22-40) and preterm birth was reported in 25 cases (29.7%). Major cardiovascular malformations were found in 55%, genitourinary in 27%, CNS and musculoskeletal in18%. Seven cases were associated to chromosomal abnormalities. The overall perinatal mortality rate was 17.8%, 5 fetuses from the isolated SUA (10.2%) and 10 from SUA associated to malformations/aneuploidies 45%. IUGR was associated in 11.9% of cases. Conclusions:The presence of SUA is associated with increased rate of malformations, aneuploidies and perinatal death even in isolated cases but not to IUGR. These data supports a closer surveillance in fetuses with this condition. Objectives: Congenital diaphragmatic hernia (CDH) is a challenging congenital anomaly to overcome lung hypoplasia. Although extensive efforts continue to be made to predict lung hypoplasia, no parameter has provided exact correlation with perinatal outcome. Our purpose was to determine the useful parameter to predict the outcome in CDH fetuses. Methods: 15 fetuses with CDH were evaluated retrospectively from January 2012 to February 2015. Observed/ expected lung to head circumference ratio (o/e LHR), diameter of pulmonary arteries (PA) and PA Doppler parameters including acceleration time/ ejection time ratio (AT/ET), peak early diastolic reverse flow (PEDRF) and pulsatility index (PI) were obtained. Lung-to-liver signal intensity ratio (LLSIR) was also measured on fetal MRI. We compare the validity of each parameter to neonatal survival, nitric oxide (NO) use after surgery and intubation periods. Results: In neonatal survival, o/e LHR and PA size had significant differences (p < 0.01, p < 0.05, respectively). In lethal cases, 3 in 5 had liver-up although no liver-up was found in survival cases. Lower LLSIR showed a trend to worse neonatal mortality (p = 0.06). PA size was only significant in NO use (p < 0.01) although PI showed a good trend (p = 0.07). Regarding intubation period, shorter AT/ET showed a good correlation to longer intubation period (r = 0.79, p < 0.05) and lower LLSIR had a trend to longer intubation period (r = −0.72, p = 0.07). Conclusions: Two dimensional evaluation might be a good predictor to neonatal mortality. Indeed Doppler parameters, especially AT/ET, might be useful for prediction of neonatal respiratory outcome in lung ...

Short oral presentation abstractsin ovine twin fetuses. The intensified release of neurotransmitters and subsequent increase of cerebral Doppler indices indicates a neuroprotective response to prolonged hypoxia with primary expected brain damages and osmotic imbalances. OP05: FIRST TRIMESTER ULTRASOUND: BEYOND NT OP05.01Only seeing what you look for: use of a detailed ultrasound protocol is associated with increased anomaly detection rates in the first trimester Objectives: First trimester ultrasound is routinely performed for chromosomal abnormality screening and is increasingly becoming a tool for the detection of fetal structural anomalies. The aim was to perform a systematic review and meta-analysis of studies assessing the detection rate of first trimester anomaly detection and to determine which factors impact rates of detection. Methods: An electronic search was conducted to identify publications assessing diagnostic accuracy of first trimester two-dimensional ultrasound for the detection of fetal structural anomalies. Sub-group analysis was performed assessing studies within one of three categories: (1) Studies reporting on major anomalies in an unselected population; (2) Studies assessing all types of anomalies in an unselected population; and (3) Studies examining all types of anomalies in high risk populations. Results: In unselected populations first trimester ultrasound had a sensitivity of 36.1% (95% C.I. 33.2-39.0) for major anomalies and was responsible for 57.1% of antenatal diagnoses. In an unselected population assessed for all types of anomalies the sensitivity was lower 33.3% (95% C.I. 31.1-35.5) while in high-risk populations it was 62.3% (95% C.I. 54.6-70.2). There was a statistically significant correlation between the use of an anatomical protocol for screening and detection rates (P < 0.0001). The use of a detailed protocol, compared to a basic protocol, also improved sensitivity (P < 0.0001). Conclusions: First trimester anomaly screening will lead detects about one third of fetal anomalies in unselected populations and two-thirds in high risk populations. It allows detection of a significant number of severe fetal anomalies at an earlier stage than is currently standard practice. Evidence suggests that the use of a detailed anatomical protocol could improve this further. OP05.02Fetal kidneys' ultrasound appearance in the first trimester

Background: Trisomies are the most common chromosomal abnormalities, being a major cause of pregnancy loss in the first trimester. Data from preimplantation embryos support the concept of recurrent aneuploidy in women with recurrent abortion. Case: The authors report a rare case with three different consecutive trisomic pregnancies: 47,XY,+21, 47,XX,+9, and 47,XX,+18. All pregnancies resulted from the same relationship and no consanguinity was present. Standard clinical cytogenetic analysis indicated that both members had normal peripheral blood karyotype, with no evidence of mosaicism in either patient or her partner. Conclusion: The present report supports the hypothesis that some women have a higher risk for nondisjunction than others of the same age. Counseling a couple with recurrent trisomies is difficult and future research on genetics of cell division are required to assist them.

The transperineal ultrasound (TPU) value of the angle of progression (AOP) during fetal head engagement, at station 0, is a critical cut-off for current obstetrical practice, especially when intrapartum instrumental interventions are required. Still, controversial measurements were reported in previous high resolution imagistic studies. Our TPU and direct “gold-standard” magnetic resonance (MRI) measurements confirm that station 0 corresponds to a 120° AOP, concordantly. Based on these findings, the fact that an AOP of 120° or greater was previously strongly associated with vaginal delivery may be due to the achievement of head engagement in labor.

Oral poster abstracts mosaicisms/translocations/deletions/sexual CA; only 2/13 women opted for TOP whereas 11/13 fetuses with normal morphology were delivered at term after a reassuring genetic counseling. 47/1423 (3,3%) fetuses had AS but normal karyotype: in 8 cases, anomalies were confirmed (3 major CHD, 1 NTD, 1 CDH, 2 nefropathies, 1 anomalous CNS). 39/1423 (2,7%) fetuses were false positive cases. Conclusions: CHD and ECA US screening performed by trained obstetricians at the time of NT measurements could identify a high rate of all aneuploidies at a low rate of false positives. Objectives:To determine the accuracy of diagnosis in the first trimester of pregnancy, and also the association between single umbilical artery (SUA) and the incidence of chromosomal and structural abnormalities. To determine whether the presence of chromosomal defects in fetuses with SUA is related to the side of the missing artery. Methods: Color flow imaging of the fetal pelvis was used to determine the number of umbilical arteries in 1346 fetuses at first trimester genetic scan, in Prenatal Diagnostic Unit, 11-13 weeks, between Jan 2008 and Dec 2010, in a high risk group. Subsequently, the same technique was used in the second trimester, at routine scan, 16-18 weeks. Follow-up rate 87.96% (1184 cases reexamined). Results: All cases offered FT satisfactory images in numbering the umbilical arteries. SUA was diagnosed in 78 (5.79%) cases. The false positive rate was 3.84%, and the false negative rate was 0%. The rate of chromosome abnormalities was significantly higher among fetuses with SUA than among those with 2 umbilical arteries -6 out of 75 (8%) versus 8/1271 or 0.62%; OR = x, 95% CI 2.3-7.1, P < 0.0001). Among fetuses with SUA, there was no significant difference in the rate of chromosome abnormalities between those with absence of the left versus the right artery. There were no chromosome abnormalities in fetuses where a single umbilical artery was an isolated sonographic finding. All fetuses with SUA and chromosomal defects had associated markers or abnormalities detected by ultrasound. Among them, 93% detected first trimester. Conclusions: SUA in the first trimester of pregnancy is feasible. It may prove an additional marker in screening for chromosomal anomalies. All chromosomally abnormal fetuses had additional genetic markers or associated malformations and they were all detected by ultrasound and subsequent invasive maneuver. 93% first trimester, 7% the second. The absence of the left artery is more frequent than the absence of the right artery. The association with chromosomal abnormalities seems to be almost equal on each side. OP21.05Appearance of the posterior fossa in fetuses with spina bifida between 11+3 and 13+6 weeks of gestation by three dimensional sonography