Topic
Fetus
About: Fetus is a research topic. Over the lifetime, 21567 publications have been published within this topic receiving 646380 citations. The topic is also known as: foetus & fœtus.
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TL;DR: The aims of this study were to assess the effect of intrauterine inflammation on fetal and neonatal brain development and to determine if the gestational age of exposure altered the maternal or fetal response to inflammation.
225 citations
TL;DR: Six mothers at risk of in utero virilization of female fetuses with 21-hydroxylase deficiency were treated with either hydrocortisone or dexamethasone in early pregnancy, with encouraging results.
225 citations
TL;DR: It is reported here that the absence of either or both COX isoforms in mice does not result in premature closure of the DA in utero, and roles for COX-1 and especially forCOX-2 are established in the transition of the cardiopulmonary circulation at birth.
Abstract: The transition to pulmonary respiration following birth requires rapid alterations in the structure of the mammalian cardiovascular system. One dramatic change that occurs is the closure and remodeling of the ductus arteriosus (DA), an arterial connection in the fetus that directs blood flow away from the pulmonary circulation. A role for prostaglandins in regulating the closure of this vessel has been supported by pharmacological and genetic studies. The production of prostaglandins is dependent on two cyclooxygenases (COX-1 and COX-2), which are encoded by separate genes. We report here that the absence of either or both COX isoforms in mice does not result in premature closure of the DA in utero. However, 35% of COX-2(-/-) mice die with a patent DA within 48 h of birth. In contrast, the absence of only the COX-1 isoform does not affect closure of the DA. The mortality (35%) and patent DA incidence due to absence of COX-2 is, however, significantly increased (79%) when one copy of the gene encoding COX-1 is also inactivated. Furthermore, 100% of the mice deficient in both isoforms die with a patent DA within 12 h of birth, indicating that in COX-2-deficient mice, the contribution of COX-1 to DA closure is gene dosage-dependent. Together, these data establish roles for COX-1, and especially for COX-2, in the transition of the cardiopulmonary circulation at birth.
224 citations
TL;DR: The results suggest that increased NADPH oxidase expression may increase levels of superoxide in persistent pulmonary hypertension of the newborn lung tissue, and that increased superoxide blunts vascular relaxations to exogenous NO while stimulating smooth muscle cell growth.
Abstract: Ligation of the ductus arteriosus in utero produces pulmonary hypertension and vascular remodeling in fetal and newborn lambs. However, the mechanisms producing these vascular changes are not well defined. Because reactive oxygen species (ROS) have been implicated as mediators of smooth muscle cell proliferation, we hypothesized that increased formation of ROS may be involved in the pathophysiology of pulmonary hypertension after in utero ductal ligation. Using ethidium fluorescence, we demonstrated an increase in superoxide levels after 9 days of ductal ligation compared with control lungs (P<0.05) that was localized to the adventitia and smooth muscle cells of hypertensive vessels. SOD-1 and SOD-2 protein levels and activities in lung, vein, and artery of hypertensive lambs were unchanged relative to controls after 2 days of ductal ligation. However, after 9 days, superoxide dismutase (SOD) activity was significantly decreased in arteries from ligated lambs without associated changes in SOD protein expr...
224 citations
TL;DR: Fetal growth standards are more appropriate in predicting the impact of birth weight category on the risk of spontaneous preterm delivery than are neonatal growth standards, according to appropriate-for-gestational-age infants.
224 citations