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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.


Papers
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Journal ArticleDOI
TL;DR: The data demonstrate that events around the time of conception have profound effects on fetal hypothalamic-pituitary-adrenal development in late gestation and that factors other than fetal exposure to excess glucocorticoids may be important.
Abstract: We investigated the effects of moderate maternal periconceptional undernutrition from 60 d before to 30 d after mating on fetal hypothalamic-pituitary-adrenal axis function in late gestation. Ewes were sampled regularly during the period of undernutrition for circulating hormone levels. Vascular catheters were inserted into ewes and their singleton fetuses at 112 d gestation (term, 145 d), and fetal ACTH(1-24) and metyrapone challenge tests were performed at 127 and 128 d. Postmortems were performed at 132 d. Fetuses of undernourished ewes (UN, n = 12) had elevated baseline cortisol concentrations (P < 0.05), compared with fetuses of ad libitum-fed ewes (n = 10). There were no differences between groups in fetal responses to ACTH challenge, but only UN fetuses demonstrated ACTH and 11-deoxycortisol responses to metyrapone (P < 0.05). UN fetuses had increased mRNA levels for proopiomelanocortin and prohormone convertase-1, but not -2, in the pars intermedia of the pituitary gland (P < 0.05). Glucocorticoid receptor mRNA levels were not different between groups in pituitary or hypothalamus. Maternal cortisol and ACTH levels during undernutrition were profoundly suppressed (P < 0.001), rather than elevated, in UN ewes. Furthermore, the normal pregnancy rise in maternal serum progesterone concentrations was delayed in undernourished mothers. These data demonstrate that events around the time of conception have profound effects on fetal hypothalamic-pituitary-adrenal development in late gestation and that factors other than fetal exposure to excess glucocorticoids may be important.

161 citations

Book ChapterDOI
TL;DR: Maternal hypertriglyceridemia has many positive effects such as contributing to fetal growth and development and serving as an energy depot for maternal dietary fatty acids, but increased TG during pregnancy appears to increase risk of preeclampsia and preterm birth.
Abstract: During pregnancy, complex changes occur in lipid profiles From the 12th week of gestation, phospholipids, cholesterol (total, LDL, HDL), and triglycerides (TG) increase in response to estrogen stimulation and insulin resistance Transition to a catabolic state favors maternal tissue lipid use as energy sources, thus sparing glucose and amino acids for the fetus In addition, maternal lipids, that is, cholesterol, are available for fetal use in building cell membranes and as precursor of bile acids and steroid hormones It is also required for cell proliferation and development of the growing body Free-fatty acids (FFA), oxidized in the maternal liver as ketone-bodies, represent an alternative fuel for the fetus Maternal hypertriglyceridemia (vs other lipids) has many positive effects such as contributing to fetal growth and development and serving as an energy depot for maternal dietary fatty acids However, increased TG during pregnancy appears to increase risk of preeclampsia and preterm birth Some have suggested that maternal hypertriglyceridemia has a role in increasing cardiovascular risk later in life This chapter reviews lipid metabolism during pregnancy to elucidate its effect on fetal growth and its potential role in pregnancy-associated complications and future cardiovascular risk

161 citations

Journal ArticleDOI
TL;DR: It is suggested that in ovine pregnancy glucocorticoid-stimulated increases in intrauterine corticotropin-releasing hormone expression directly increase fetal placental prostaglandin production, and indirectly increase prostag landin production by maternal uterine tissues through the stimulation of placental estradiol synthesis.
Abstract: Birth in many animal species and in humans is associated with activation of hypothalamic-pituitary-adrenal function in the fetus and the increased influence of glucocorticoids on trophoblast cells of the placenta and fetal membranes. We suggest that in ovine pregnancy glucocorticoids directly increase fetal placental prostaglandin production, and indirectly increase prostaglandin production by maternal uterine tissues through the stimulation of placental estradiol synthesis. The events of ovine parturition are compared with those of human parturition. In the latter, we suggest similar direct effects of glucocorticoids on prostaglandin synthesis and metabolism in fetal membranes and similar indirect effects mediated by glucocorticoid-stimulated increases in intrauterine corticotropin-releasing hormone expression.

161 citations

01 Feb 1980
TL;DR: Compared to the pattern of glucose utilization, the comparison of uterine and umbilical amino acid uptakes shows that the bulk of the amino acids taken up by the pregnant uterus is transferred to the fetus.
Abstract: The uptakes of oxygen, glucose, and amino acids by the pregnant uterus via the uterine circulation and by the fetus via the umbilical circulation have been measured in sheep during the last month of gestation. The umbilical uptakes of oxygen and glucose are approximately 55 and 28%, respectively, of the total uterine uptake. This discrepancy between uterine and umbilical uptakes is due primarily to a large utilization rate of oxygen and glucose by the placenta. Part of the placental utilization of glucose can be accounted for by placental lactate excretion into both maternal and fetal blood. In marked contrast to the pattern of glucose utilization, the comparison of uterine and umbilical amino acid uptakes shows that the bulk of the amino acids taken up by the pregnant uterus is transferred to the fetus. The placenta utilizes glutamate of fetal origin and produces ammonia, which is excreted primarily into the maternal circulation.

161 citations

Journal ArticleDOI
TL;DR: The results suggest that maternal stress, in terms of trait anxiety, influences fetal cerebral circulation, suggesting a change in blood distribution in favor of brain circulation in the fetuses.

161 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20249
20232,267
20224,825
2021623
2020515
2019506