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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.


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Journal ArticleDOI
TL;DR: In this paper, it was shown that major components of fetal brain sparing during acute hypoxia are triggered exclusively by a carotid chemoreflex and that they are modified by endocrine agents and vascular oxidant tone.
Abstract: How the fetus withstands an environment of reduced oxygenation during life in the womb has been a vibrant area of research since this field was introduced by Joseph Barcroft, a century ago. Studies spanning five decades have since used the chronically instrumented fetal sheep preparation to investigate the fetal compensatory responses to hypoxia. This defence is contingent on the fetal cardiovascular system, which in late gestation adopts strategies to decrease oxygen consumption and redistribute the cardiac output away from peripheral vascular beds and towards essential circulations, such as those perfusing the brain. The introduction of simultaneous measurement of blood flow in the fetal carotid and femoral circulations by ultrasonic transducers has permitted investigation of the dynamics of the fetal brain sparing response for the first time. Now we know that major components of fetal brain sparing during acute hypoxia are triggered exclusively by a carotid chemoreflex and that they are modified by endocrine agents and the recently discovered vascular oxidant tone. The latter is determined by the interaction between nitric oxide and reactive oxygen species. The fetal brain sparing response matures as the fetus approaches term, in association with the prepartum increase in fetal plasma cortisol, and treatment of the preterm fetus with clinically relevant doses of synthetic steroids mimics this maturation. Despite intense interest into how the fetal brain sparing response may be affected by adverse intrauterine conditions, this area of research has been comparatively scant, but it is likely to take centre stage in the near future.

238 citations

Journal ArticleDOI
TL;DR: Gender differences in mode of delivery, fetal heart rate in labour, acidaemia at birth, and age degenerative changes will also be discussed.

238 citations

Journal ArticleDOI
TL;DR: Stratification of umbilical artery blood pH values, Apgar scores, and combinations of these dependent variables in relation to newborn clinical outcomes revealed that infants must be severely depressed at delivery before birth asphyxia can be reliably diagnosed.

238 citations

Journal ArticleDOI
TL;DR: It may not be feasible to fix precisely the time of onset of immunologic responsiveness in a species, inasmuch as it appears to differ so greatly from one antigen to another.
Abstract: The fetal lamb in utero is able to form large amounts of specific antibody in response to antigenic stimulus as early as the 66th to 70th day of the 150 day gestation period. Among the several antigens employed, the fetal lamb responded earliest, and with the highest titers, to bacteriophage φX. Slightly less effective as an antigen was horse ferritin, while ovalbumin proved to be a weak antigen, especially in younger fetuses. Ineffective in stimulating an antibody response at any time during fetal or early neonatal life were diphtheria toxoid, Salmonella typhosa , and BCG. Thus, it may not be feasible to fix precisely the time of onset of immunologic responsiveness in a species, inasmuch as it appears to differ so greatly from one antigen to another. The quantity of antibody found 10 days after φX immunization was not significantly different in fetuses injected at 60 to 120 days of gestation. The earliest anti-phage antibody produced by the lamb fetus is a macroglobulin sensitive to the action of 2-mercaptoethanol. Only in older fetuses with longer lasting stimuli were appreciable amounts of 7S γ-globulin antibodies formed. The conformity of these observations to theories on the ontogenesis of the immune response is discussed.

238 citations

Journal ArticleDOI
TL;DR: The fetal sex predicted by PCR analysis of the isolated trophoblast cells accorded with that ascertained by karyotyping of chorionic villus samples in eleven of twelve women studied in early pregnancy and with the sex of the baby on delivery in one woman studied at 34 weeks' gestation.

237 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