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Aspects of Praematurity and Dysmaturity

Groningen 10–12 May 1967

  • J. H. P. Jonxis
  • H. K. A. Visser
  • J. A. Troelstra

Part of the Nutricia Symposium book series (NUSY, volume 2)

Table of contents

  1. Front Matter
    Pages I-XI
  2. Role of the Placenta

    1. Front Matter
      Pages 1-1
    2. Back Matter
      Pages 25-34
  3. Assessment of Foetal Development

    1. Front Matter
      Pages 35-35
    2. A. Minkowski, S. Saint-Anne Dargassies, C. Dreyfus-Brisac, J. Cl. Larroche, J. Vignaud, C. Amiel
      Pages 46-56
    3. H. C. Schwartz, T. J. Gribble, F. Welland, W. Nijhof, J. H. P. Jonxis
      Pages 57-67
    4. O. Koldovský, A. Heringová, V. Jirsová, J. Kraml, H. Pelichová, J. Uher
      Pages 91-98
    5. Back Matter
      Pages 99-116
  4. Experimental Aspects of Dysmaturity

    1. Front Matter
      Pages 117-117
    2. J. S. Wigglesworth
      Pages 119-126
    3. Back Matter
      Pages 139-146
  5. Hereditary and Environmental Aspects of Low Birthweight

    1. Front Matter
      Pages 147-147
    2. L. O. Lubchenco, C. Hansman, Leena Bäckström
      Pages 149-166
    3. Margaret Ounsted
      Pages 167-188
    4. Back Matter
      Pages 189-197
  6. Adaptation of the Low Birthweight Infant to Extra-Uterine Life

    1. Front Matter
      Pages 199-199
    2. J. H. P. Jonxis, J. J. Van der Vlugt, C. J. De Groot, E. R. Boersma, E. D. K. Meijers
      Pages 201-209
    3. Robert Schwartz, Peter A. J. Adam, Katherine King, David Kornhauser
      Pages 210-227
    4. Back Matter
      Pages 245-259
  7. Obstetrical and Preventive Aspects of Dys Maturitythe Obstetrician and Dysmaturity

    1. Front Matter
      Pages 261-261
    2. G. J. Kloosterman
      Pages 263-280
    3. Back Matter
      Pages 281-284
  8. Developmental Aspects

    1. Front Matter
      Pages 285-285
    2. C. M. Drillien
      Pages 287-302
    3. Back Matter
      Pages 323-328
  9. Back Matter
    Pages 329-356

About this book

Introduction

The concept of the foeto-placental unit as an integrated endocrine organ has been defined recently by many in vivo studies at the 17th- 20th week of gestation. A functioning foeto-placental unit is necessary for most of the increased oestrogen production of pregnancy and for the provision of glucocorticoids and aldosterone to the foetus. Neither the foetus nor the placenta alone have the necessary enzyme systems for the synthesis of these groups of steroids. However, when the foetus and placenta function as a unit, all of the enzyme systems are present for the synthesis of these steroids from circulating cholesterol. The placenta, but not the mid-gestation foetal adrenal, can synthesize physiologically significant amounts of pregnenolone from circulating cholesterol. Part of the pregnenolone is converted to progesterone in the placenta by the 3~-HSD system (absent in the foetus). The progesterone is transferred to the foetus where it is transformed by C-II, C-17, C-18 and C-21 hydroxylases (all absent in the placenta) to cortisol, corticosterone and aldosterone. Pregnenolone transferred from the placenta to the foetus undergoes 171X-hydroxylation, side­ chain splitting and sulfurylation (absent in the placenta) and is converted to DHAS. The DHAS may undergo 161X-hydroxylation (absent in the placenta) in the foetal liver and be transported to the placenta as 161X-OH-DHAS. There it is subjected to a neutral steroid sulfatase (absent in the foetus) and is converted to oestriol by action of the 3~-HSD system and the aromatizing enzyme system.

Keywords

birth complications fetus growth placenta regulation

Editors and affiliations

  • J. H. P. Jonxis
    • 1
  • H. K. A. Visser
    • 2
  • J. A. Troelstra
    • 1
  1. 1.Dept. PaediaticsState UniversityGroningenNetherlands
  2. 2.Dept. PaediaticsMedical SchoolRotterdamNetherlands

Bibliographic information

  • DOI https://doi.org/10.1007/978-94-010-3428-9
  • Copyright Information Springer Science+Business Media B.V. 1968
  • Publisher Name Springer, Dordrecht
  • eBook Packages Springer Book Archive
  • Print ISBN 978-94-010-3430-2
  • Online ISBN 978-94-010-3428-9
  • Buy this book on publisher's site