Donald School Journal of Ultrasound in Obstetrics and Gynecology

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VOLUME 17 , ISSUE 1 ( January-March, 2023 ) > List of Articles


Infants at the Limits of Viability: Medical and Ethical Aspects

Milan Stanojevic

Keywords : Artificial uterus, Limits of viability, Microgravity, Outcome, Prematurity, Treatment

Citation Information : Stanojevic M. Infants at the Limits of Viability: Medical and Ethical Aspects. Donald School J Ultrasound Obstet Gynecol 2023; 17 (1):79-87.

DOI: 10.5005/jp-journals-10009-1963

License: CC BY-NC 4.0

Published Online: 14-04-2023

Copyright Statement:  Copyright © 2023; The Author(s).


There is a continuity of intrauterine to extrauterine life. With the existing level of knowledge and technical possibilities, extrauterine survival above 50% without major morbidity in some developed countries is possible at 22 gestational weeks (GW), while anecdotal survival has been described even at 21 GW + 4 days. The possibility of extending the survival of the smallest premature infants has been challenging for many decades. Good results of the survival of tiny and immature infants are improving in developed countries, but survival without major morbidity is still stagnant. From the historical point of view, limits of viability changed in the last 150 years for many medical, economic, ethical, and other reasons from 32 to 22 weeks of gestation, but always related to already born infants. Almost 70 years ago and recently, treating extreme prematurity remains a difficult medical issue due to many iatrogenic injuries which can hardly be avoided by using existing modes of therapy, including a modern way of thinking, sophisticated technology, and drugs. Recent technological advancements may enable the translation of experimental models of the artificial uterus (AU) and the artificial womb technology (AWT), termed ectogenesis which is the partial or complete maturation of a developing embryo or fetus outside the human body, to clinical practice, raising many technical, medical, and ethical dilemmas. The AWT is investigated on animal models only, but even in the research model, microgravity and gravity (G), age, thermoregulation, and oxygenation (GATO) hypotheses have not been mentioned or considered, although they might be important for the development of the fetus at early gestations. It might be advisable to change the way of thinking and find the reasons pro and contra of microgravity use in AWT research, which may improve care for fetuses born at the lower limits of viability.

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