Talk:2009 Lecture 23

Introduction

There are a great number of comprehensive, scientific and general, books and articles that cover Parturition, Birth or Childbirth.

Birth or parturition is a critical stage in development, representing in mammals a transition from direct maternal support of fetal development, physical expulsion and establishment of the newborns own respiratory, circulatory and digestive systems.

File:1770birth sm.jpg	File:JAMA CesareanDelivery.gif	File:Birth.jpg
Birth - Stage 1	[birth6.htm Caesarean]	Newborn infant

These notes only cover the biological processes involved in birth [birth4.htm fetal signaling changes] and [birth5.htm maternal signaling changes]. Note that there is a growing worldwide trend in developed countries toward [birth6.htm caesarean section] delivery.

Other Pages: [../Notes/respire6.htm Respiratory Development - Birth] |

Some Recent Findings

Markovic D, Vatish M, Gu M, Slater D, Newton R, Lehnert H, Grammatopoulos DK. The onset of labour alters corticotropin-releasing hormone type 1 receptor (CRH-R1) variant expression in human myometrium: putative role of IL-1{beta} Endocrinology. 2007 Apr 12

Zakar T, Hertelendy F. Progesterone withdrawal: key to parturition. Am J Obstet Gynecol. 2007 Apr;196(4):289-96.

"In most subprimate placental mammals, the withdrawal of progesterone before the initiation of labor is manifest by a significant drop in circulating progesterone levels, which is due to either luteolysis or changes in placental steroidogenesis, which shunts precursors towards estrogen production. No such events can be demonstrated in human pregnancy."

Birth Models

File:1770birth sm.jpg	File:1770birth2 sm.jpg
Cephalic presentation of engagement	Disengagement of the head in vertex presentation

(More? [../history/page1770.htm Development History - 1770 - Obstetric Models])

Reading

Human Embryology (2nd ed.) Larson Chapter 15 p471-488
The Developing Human: Clinically Oriented Embryology (6th ed.) Moore and Persaud Chapter 7 p129-167
Before we Are Born (5th ed.) Moore and Persaud Ch
Essentials of Human Embryology Larson Ch
Human Embryology Fitzgerald and Fitzgerald
General Reading- Pregnancy and Childbirth S Kitzinger Doubleday, Sydney ISBN 0 86824 048 6

Gestation Period

The median duration of gestation for first births from assumed ovulation to delivery was 274 days (just over 39 weeks). For multiple births, the median duration of pregnancy was 269 days (38.4 weeks).

"...one should count back 3 months from the first day of the last menses, then add 15 days for primiparas or 10 days for multiparas, instead of using the common algorithm for Naegele's rule." Reference: Mittendorf R, Williams MA, Berkey CS, Cotter PF. The length of uncomplicated human gestation. Obstet Gynecol. 1990 Jun;75(6):929-32

Historically, Franz Carl Naegele (1777-1851) developed the first scientific rule for estimating length of a pregnany.

This topic has been separated into pages related to the whole signaling [birth3.htm process overview].

Preterm Birth

There is a specific page online [birthpremature.htm Premature Birth] being currently prepared.

A study has shown that risks of preterm birth in low abnormal birth weight (intrauterine growth restriction) and high (large for gestational age) categories are 2- to 3-fold greater than the risk among appropriate-for-gestational-age infants.

In another study of placenta previa, low birth weight is due mainly to preterm delivery and to a lesser extent with fetal growth restriction.

(More? HSTAT - Management of Preterm Labor)

Reference: Lackman F, Capewell V, Richardson B, daSilva O, Gagnon R. The risks of spontaneous preterm delivery and perinatal mortality in relation to size at birth according to fetal versus neonatal growth standards. Am J Obstet Gynecol. 2001 Apr;184(5):946-53.

Ananth CV, Demissie K, Smulian JC, Vintzileos AM. Relationship among placenta previa, fetal growth restriction, and preterm delivery: a population-based study. Obstet Gynecol. 2001 Aug;98(2):299-306.

(More? [birthpremature.htm Premature Birth])

Computer Activities

Birth Date Calculator

HTML: <noscript>NOTE: You need Javascript to use the calculator, which your browser has apparently disabled.HTML: </noscript>

When did your last period begin? Your approximate birth (due) date is:

== References ==

Links require internet connection.

NCBI Bookshelf

Health Services/Technology Assessment Text (HSTAT) Bethesda (MD): National Library of Medicine (US), 2003 Oct.

Management of Preterm Labor

Management of Prolonged Pregnancy

Cesarean Childbirth

Vaginal Birth After Cesarean (VBAC) Volume 1 and Volume 2

Reviews

Bernal AL. Overview of current research in parturition. Exp Physiol. 2001 Mar;86(2):213-22. Review.
Young IR. The comparative physiology of parturition in mammals. Front Horm Res. 2001;27:10-30.
Schwartz J, McMillen IC. Fetal hypothalamus-pituitary-adrenal axis on the road to parturition. Clin Exp Pharmacol Physiol. 2001 Jan-Feb;28(1-2):108-12. Review.
Challis JRG, Matthews SG, Gibb W, Lye Endocrine and paracrine regulation of birth at term and preterm. Endocr Rev. 2000 Oct;21(5):514-50. Review.
Muglia LJ. Genetic analysis of fetal development and parturition control in the mouse. Pediatr Res. 2000 Apr;47(4 Pt 1):437-43. Review.
Drover JW, Casper RF. Initiation of parturition in humans. Can Med Assoc J. 1983 Feb 15;128(4):387-92.

Articles

Ochedalski T, Lachowicz A. Maternal and fetal hypothalamo-pituitary-adrenal axis: different response depends upon the mode of parturition. Neuro Endocrinol Lett. 2004 Aug;25(4):278-82.

Search PubMed Now: childbirth | parturition

Normal

[../Stats/page2.htm Australian Birth Statistics]

[../Stats/page1.htm International and Australian Population Statistics]

[../Stats/page3.htm WHO Normal Population Statistics]

Fact Sheets

[../Stats/page3a.htm#perinatal Global Perinatal and Maternal Causes of Death]

[../Stats/page4a.htm Population Comparisons between Countries]

[../Stats/page4a.htm#Population%20Data Developed and developing]

[../Stats/page4a.htm#au1 Australian neighbours]

[../Stats/page4a.htm#au2 Australian Trading Partners]

Normal population statistics derived from a number of different sources (as shown on individual pages).

Internal LinksBirth