HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Comline, R. S. Articles by Silver, M. Search for Related Content PubMed PubMed Citation Articles by Comline, R. S. Articles by Silver, M.

1. Changes in the composition of foetal and maternal blood have been followed during the last 5-10 days of gestation and throughout parturition in the conscious sheep.

2. Catheters were placed in the foetal inferior vena cava through a tarsal vein and in a maternal uterine vein in ten ewes under sodium pentobarbitone anaesthesia. In four of the foetuses blood pressure and heart rates were recorded before and during parturition from an arterial catheter.

3. Foetal blood gas tensions, pH and PCV remained stable during the latter part of gestation and throughout labour until 15 min before delivery, when P_O2 and pH fell while PCV and P_CO2 rose in about 50% of the foetuses examined.

4. Metabolite levels were also relatively stable at the end of gestation. Plasma glucose in both maternal and foetal blood rose during the hour before birth, while foetal plasma lactate was elevated as early as 4 hr before birth and was unrelated to any maternal changes. Foetal fructose levels were maintained until after delivery.

5. Rises in foetal blood pressure before birth were associated with uterine contractions. Foetal heart rate changes during labour varied in different individuals. The heart rate either fell gradually before birth or there was little change until a sudden drop at delivery.

6. The most striking changes in the lamb occurred at, or a few minutes after, birth; pH and P_O2 fell, P_CO2 and PCV rose, and bradycardia at delivery was succeeded by prolonged tachycardia. There were marked increases in plasma glucose and lactic acid at this time.

7. P_O2 rose rapidly once respiration was established, while pH and P_CO2 levels were restored within -1 hr. Plasma FFA levels rose rapidly in the lambs 10-30 min after birth and remained high, while plasma glucose, lactate and fructose concentrations declined slowly in the 1-2 hr after birth, although suckling raised the plasma glucose levels. Considerable individual variation in the metabolite levels was found in both ewes and lambs.

8. In the majority of ewes delivery was associated with an abrupt maternal hyperglycaemia, with a much smaller rise in lactate and virtually no change in maternal blood gases or pH.

9. These findings are discussed in relation to existing information on new-born lambs and the human infant during birth.

This article has been cited by other articles:

				D. A. Giussani, C. E. Salinas, M. Villena, and C. E. Blanco The role of oxygen in prenatal growth: studies in the chick embryo J. Physiol., December 15, 2007; 585(3): 911 - 917. [Abstract] [Full Text] [PDF]

				J.W. Ward, A.J. Forhead, F.B.P. Wooding, and A.L. Fowden Functional Significance and Cortisol Dependence of the Gross Morphology of Ovine Placentomes During Late Gestation Biol Reprod, January 1, 2006; 74(1): 137 - 145. [Abstract] [Full Text] [PDF]

				J. W. Ward, F. B. P. Wooding, and A. L. Fowden Ovine feto-placental metabolism J. Physiol., January 15, 2004; 554(2): 529 - 541. [Abstract] [Full Text] [PDF]

				A. J. Forhead, J. Li, R. S. Gilmour, M. J. Dauncey, and A. L. Fowden Thyroid hormones and the mRNA of the GH receptor and IGFs in skeletal muscle of fetal sheep Am J Physiol Endocrinol Metab, January 1, 2002; 282(1): E80 - E86. [Abstract] [Full Text] [PDF]

				K. Satoh, F. Shirota, T. Tsunajima, C. J. Beinlich, H. E. Morgan, and K. Ichihara Limitation of heart growth in neonatal piglets by simvastatin and atorvastatin: comparison with pravastatin Am J Physiol Heart Circ Physiol, June 1, 2001; 280(6): H2746 - H2751. [Abstract] [Full Text] [PDF]

				P.T. Sangild, M. Schmidt, H. Jacobsen, A.L. Fowden, A. Forhead, B. Avery, and T. Greve Blood Chemistry, Nutrient Metabolism, and Organ Weights in Fetal and Newborn Calves Derived from In Vitro-Produced Bovine Embryos Biol Reprod, June 1, 2000; 62(6): 1495 - 1504. [Abstract] [Full Text]

				J. LI, R. S. GILMOUR, J. C. SAUNDERS, M. J. DAUNCEY, and A. L. FOWDEN Activation of the adult mode of ovine growth hormone receptor gene expression by cortisol during late fetal development FASEB J, March 1, 1999; 13(3): 545 - 552. [Abstract] [Full Text]

				J. J. Smolich, H. S. Cox, and M. D. Esler Contribution of lungs to desipramine-induced changes in whole body catecholamine kinetics in newborn lambs Am J Physiol Regulatory Integrative Comp Physiol, January 1, 1999; 276(1): R243 - R250. [Abstract] [Full Text] [PDF]

				K. A. Wong, A. Bano, A. Rigaux, B. Wang, B. Bharadwaj, S. Schurch, F. Green, J. E. Remmers, and S. U. Hasan Pulmonary vagal innervation is required to establish adequate alveolar ventilation in the newborn lamb J Appl Physiol, September 1, 1998; 85(3): 849 - 859. [Abstract] [Full Text] [PDF]

				A. J. Forhead, J. Li, R. S. Gilmour, and A. L. Fowden Control of hepatic insulin-like growth factor II gene expression by thyroid hormones in fetal sheep near term Am J Physiol Endocrinol Metab, July 1, 1998; 275(1): E149 - E156. [Abstract] [Full Text] [PDF]

				J. Li, J. C. Saunders, A. L. Fowden, M. J. Dauncey, and R. S. Gilmour Transcriptional Regulation of Insulin-like Growth Factor-II Gene Expression by Cortisol in Fetal Sheep during Late Gestation J. Biol. Chem., April 24, 1998; 273(17): 10586 - 10593. [Abstract] [Full Text] [PDF]

				J. J. Smolich, H. S. Cox, P. J. Berger, A. M. Walker, G. Eisenhofer, and M. D. Esler Left Ventricular Norepinephrine and Epinephrine Kinetics at Birth in Lambs Circ. Res., September 19, 1997; 81(3): 438 - 447. [Abstract] [Full Text]