Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2023 Mar 2;23:137. doi: 10.1186/s12884-022-05221-w

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© The Author(s) 2023

Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

PMC Copyright notice

Fig. 1 — Uterine contraction and relaxation: metabolic, autonomic and haemodynamic effects for mother, uterus, and fetus. Note: Equal lengths of contraction and relaxation are for illustration only. In labour the period of contraction is relatively shorter, with a relatively longer period of relaxation that allows full replenishment of blood supply to the uterus and fetus, as shown in the figure. As labour progresses, contractions become stronger and more frequent with relatively shorter periods of relaxation in between. Infusions of synthetic oxytocin cause stronger and more frequent contractions, which further shortens the relative time for replenishment in uterine tissues. This may increase maternal pain and stress and reduce fetal blood flow. In this way, administration of synthetic oxytocin may exaggerate maternal metabolic and autonomic consequences and fetal blood flow reductions induced by the contractions of physiological birth, as illustrated. Abbreviations: O_2: oxygen; pH: measure of acidity; PSNS: parasympathetic nervous system; SNS: sympathetic nervous system (Figure 1 copyright S Buckley and K Uvnäs-Moberg, 2023)