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.

Body composition of the reference fetus

Abstract: Published data from chemical analyses of human fetuses have been utilized to construct a reference fetus of representative body composition. For gestational ages 24 through 40 weeks, body composition of the reference fetus is presented, including water, lipid, protein and major minerals. Concentrations of water, sodium, and chloride per unit of body weight decrease with increasing gestational age, whereas those of protein, lipid, calcium, phosphorus, magnesium and potassium increase. From the estimates of body composition at each age and from the gain in body weight, composition of gain and daily increments of body components have been calculated.

Pathology of the placenta.

Abstract: The Development and Structure of the Placenta. Physiology of the Placenta. Abnormalities of Placentation. The Placenta in Multiple Pregnancy. Macroscopic Abnormalities of the Placenta. Histological Abnormalities of the Placenta. The Placenta in Pregnancies of Abnormal Duration. The Placenta in Maternal Disorders. The Placenta in Abnormalities and Disorders of the Fetus. The Placenta in Abortion. Infections and Inflammatory Lesions of the Placenta. Immunopathology of the Placenta. Nontrophoblastic Tumours of the Placenta. Trophoblastic Tumours of the Placenta. Pathology of the Umbilical Cord. Pathology of the Membranes. Appendix 1: Pathological Examination of the Placenta. Appendix 2: Placental Weight. Appendix 3: Placental Biopsy. Appendix 4: Medico-Legal Aspects of Placental Pathology.

Pathology of the placenta.

Abstract: The placenta has a considerable functional reserve capacity, easily repairs ischaemic damage, is able to compensate for toxic injury and does not appear to age. Most of the macroscopically visible abnormalities of the placenta are of no functional significance, the major exception to this general banality being the uncommon large haemangioma which can cause complications in the mother, fetus and neonate. Most of the histological abnormalities seen in the placental villi represent a reaction to alterations in either maternal or fetal blood flow through the placenta, but a failure of adequate maturation of the villous tree may impair the functional efficiency of the placenta, as may defective trophoblastic differentiation. Infections of the placenta are important but do not influence placental function, whilst there is currently no firm evidence that the placenta ever suffers immune-mediated damage. Intrinsic placental 'insufficiency' is extremely rare and it is becoming increasingly clear that this clinical syndrome is usually due to a restricted supply of maternal oxygen and nutrients as a result of inadequate transformation of the spiral arteries into uteroplacental vessels. This failure of placentation represents an abnormality of the relationship between fetal and maternal tissues at a relatively early stage of pregnancy, and it is only by gaining a better understanding of this relationship that the problems posed by such conditions as pre-eclampsia and idiopathic intrauterine growth retardation will be answered.

Cardiovascular physiology of pregnancy.

Abstract: Pregnancy is a dynamic process associated with significant physiological changes in the cardiovascular system These changes are mechanisms that the body has adapted to meet the increased metabolic demands of the mother and fetus and to ensure adequate uteroplacental circulation for fetal growth and development Insufficient hemodynamic changes can result in maternal and fetal morbidity, as seen in preeclampsia and intrauterine growth retardation In addition, maternal inability to adapt to these physiological changes can expose underlying, previously silent, cardiac pathology, which is why some call pregnancy nature’s stress test Indeed, cardiovascular disease in pregnancy is the leading cause of maternal mortality in North America1 We therefore review here the normal cardiovascular physiology of pregnancy to provide clinicians with a basis for understanding how the presence of cardiovascular disease may compromise the mother and fetus and how their decisions about medical care may need adjustment Pregnancy is associated with vasodilation of the systemic vasculature and the maternal kidneys The systemic vasodilation of pregnancy occurs as early as at 5 weeks and therefore precedes full placentation and the complete development of the uteroplacental circulation2 In the first trimester, there is a substantial decrease in peripheral vascular resistance, which decreases to a nadir during the middle of the second trimester with a subsequent plateau or slight increase for the remainder of the pregnancy3 (Figure 1) The decrease is ≈35% to 40% of baseline Systemic vascular resistance increases to near-prepregnancy levels postpartum,4 and by 2 weeks after delivery, maternal hemodynamics have largely returned to nonpregnant levels5 Increased vascular distensibility, or compliance, has been observed in normal human pregnancy starting in the first trimester6 Systemic vascular resistance increases to near-prepregnancy levels postpartum4 Vasodilation of the kidneys results in a 50% increase in renal plasma flow and glomerular filtration …