No abstract

Objective To assess the effects of late small-forgestational-age (SGA)

Objective To assess cognitive outcomes and structural changes in the central nervous system, the latter using a novel approach to examine changes in neuronal integrity of the optic nerve, in children at 5-6 1 / 2 years of age who were born small-for-gestational age (SGA)

Purpose Evaluate the influence of intrauterine exposure to tobacco in the development of visual function and the retinal nerve fiber layer (RNFL) in school‐age children. Methods Retrospective cohort study with children from 5 to 14 years old. The studied subjects were divided into two groups according to the antecedent of exposure to tobacco during pregnancy: children of cigarette smoking mothers during pregnancy (exposed) and children of non‐smoking mothers (not exposed). In both groups were assessed visual acuity (VA), Ishihara test and RNFL average thickness obtained by optical coherence tomography (OCT). The mean and standard deviation of the variables were calculated, and U Mann‐Whitney test was performed for comparison of data. Results 48 children were studied, 25 boys and 23 girls. The exposed group was composed of 8 children and 40 were in the non‐exposed group. The evaluation of the visual function (VA and Ishihara test), showed no statistically significant differences between groups. However, the RNFL average thickness was of 94.64 and 103.88 microm for the exposed and non‐exposed group, respectively; these data showed statistically significant differences between both values. Conclusion The intrauterine exposure to tobacco is associated with a poor development of the optic nerve. This fact determines a lower RNFL thickness measured by OCT.

The purpose of this study was to investigate changes in human placental oxygenation during maternal hyperoxia by using the non-invasive blood oxygen level dependent (BOLD) magnetic resonance imaging (MRI) technique. Previous we have shown, that changes in the BOLD signal are closely related to changes in tissue oxygenation. Methods: Eight healthy pregnant women in gestational week 28 to 36 were included in the study. Maternal hyperoxia was induced for 5 minutes, and the BOLD MRI scan was performed using a 1.5 Tesla system with the following parameters: repetition time = 8000 ms, echo-time = 50 ms and flip angle = 90. Results: In the BOLD image the normoxic placenta appeared heterogeneous with darker areas located to the fetal side and brighter areas to the maternal side. During hyperoxia the placenta became brighter and the structure more homogeneous (image). The BOLD signal of the total placenta increased by 16.6 ± 7.6% (mean ± SD), (P = 0.0002). The increase was predominantly seen in the darker areas of the placenta 33.0 ± 13.9% when compared to the brighter areas where the increase was only 10.7 ± 8.9%. Conclusions: During hyperoxia placental oxygenation was increased predominantly in the darker areas. This finding and the anatomic location of the dark placental areas suggests that the darker areas represent the fetal circulation of the placenta. To our knowledge this is the first study that successfully visualizes changes in placental oxygenation by using the BOLD MRI technique.