"fixed conception" is a correct and usable phrase in written English.
You can use it when referring to an idea or belief that is firmly held and difficult to change. For example, you can say "He has a fixed conception of the world and does not listen to other opinions."
These paired thoughts, that our practical life is experimental and that we have no firmly fixed conception of what it is for something to "work," come to the fore in Dewey's pragmatist ethics (see esp. Dewey 1967 [1922]).
Natality challenges a fixed conception of identity, makes evident that self and non-self are not in opposition, and that identity "erupts from the flesh" (39).
Such studies should also avoid distortions caused by factors occurring later in life (such as the onset of disease) because genetic variants are fixed at conception. 8 Hence, mendelian randomisation analyses should confer certain design advantages akin to those in randomised trials.
Sex is fixed at conception and cannot be changed".
Constellations embodied a fixed, classical conception of the universe.
Because our genes are fixed at conception, and our genetic variation can be thought of as random, they allow scientists to explore a sort of "natural experiment", meaning they can look beyond many of the social or environmental factors that can muddy the waters of our hot drink habits.
Economists should not fall victim to thinking that just because one's genetic code is fixed at conception, genetic-expression may vary across the lifecycle.
Many critics point to the impossibility of manipulating genetic traits that are fixed at conception in a manner that is analogous to administering a treatment in a randomized experiment.
Genetic variants are generally not associated with typical confounders in observational epidemiology and, being fixed from conception, may be informative about the direction of causality [60].
Genetic variants are ideal candidate IVs, because genes typically have specific functions, and the genetic code for each individual is fixed at conception, meaning that variants cannot be influenced by social or environmental factors (14).
The new science tells us that this does not happen according to a fixed blueprint incised at conception into our genes; rather, it happens because of the way our genotype interacts with our environment, stimulating responses in our core physiological processes throughout our lifetime.
