In-utero evaluation of the fetal umbilical-portal venous system among fetuses with persistent right umbilical vein: Two-and three-dimensional ultrasonographic study.

OBJECTIVE: The aim of this study was to describe the anatomy of the portal system in fetuses with persistent right umbilical vein (PRUV). METHODS: Prospective observational study of fetuses diagnosed with PRUV. All patients underwent a comprehensive portal system anatomy scan supplemented by two-dimensional (2D) and three-dimensional (3D) color doppler modalities. RESULTS: 29 fetuses with PRUV were studied. We perceived an identical anatomical pattern in 28 fetuses. The right umbilical vein drains to the portal sinus (future right portal vein, RPV), which has a configuration of a left portal vein (LPV) in the normal left portal system, with three emerging branches: inferior (RPVi), medial (RPVm) and superior (RPVs). The RPV then courses to the left, towards the stomach to the point of the bifurcation of the main portal vein (MPV) to become the left portal vein. The LPV has an RPV configuration in a normal portal system with anterior (LPVa) and posterior (RPVp) branches. This anatomical layout mimics a mirror image of the normal anatomy of left portal system. CONCLUSION: PRUV has unique umbilical portal venous anatomy, which is a mirror image of the normal left portal system. It can be demonstrated prenatally and serve as an additional tool for prenatal diagnosis of PRUV.

Mode of delivery and neonatal outcome in uncomplicated monochorionic twin pregnancies.

OBJECTIVE: The association between of mode of delivery and perinatal morbidity in monochorionic (MC) twins is not clear. Thus there is no agreement regarding the optimal mode of delivery of MC twins. The aim of this study is to determine the impact of the mode of delivery on neonatal outcome of uncomplicated MC twins in a tertiary center with a strict policy of delivering MC twins by 37 weeks' gestation. METHODS: Retrospective analysis of all uncomplicated MC twin deliveries at a tertiary referral hospital during a 5-year period. Complicated MC pregnancies (fetal death, selective reduction, twin to twin transfusion syndrome, fetal growth restriction of one or both twins or major fetal anomalies) were excluded. Induction of labor or planned caesarean sections of uncomplicated MC pregnancies was conducted between 35 and 37 weeks of gestation. Neonatal outcomes of MC twins were compared according to the mode of delivery. Moreover, mode of delivery was compared with a control group of 1934 dichorionic (DC) twin pregnancies delivered during the same period. RESULTS: The rate of Caesarean section was 63.4% in uncomplicated MC/DA twins pregnancies and this was similar to our rate in DC twins (61%, p = 0.65). Multivariate analysis revealed that adverse neonatal outcome was significantly associated with gestational age at delivery, neonatal birth weight discordance and male gender but not with the intended or actual mode of delivery. CONCLUSION: Delivering MC twin pregnancies by 37 weeks' gestation is associated with similar rate of vaginal deliveries compared with DC twin pregnancies. The neonatal outcome was not affected by the mode of delivery, and therefore vaginal delivery seems safe in MC twins.