Clearly, humans can survive in 1.01 g or 0.99 g

They should do OK in 1.1 or 0.9 g, with some physiological adaptation to the changed stresses, especially if they grow up in that environment.

I can see difficulties with extremes as wide apart as 1.5 or 0.38 g, but the combination of physiological adaption and technological support should make these environments liveable.

Whether conception, & pregnancy to full term are possible at these extremes is a great unknown. Many SF stories have carried the thread of returning to Earth, or to an Earth-simulating habitat for pregnancy and birth.

At present, much of this is pure speculation. Regrettably, the opportunity has not been taken for simple experiments such as that proposed by Bob Zubrin to breed a colony of space mice in a Mars gravity simulator (centrifuge) to examine the effect on mamalian fertility and development of partial gravity. What are the effects on bone mass, vascular systems etc? Do body proportions vary?

Most of the effort in space medicine has been wasted, in my opinion, of studies of zero-g physiological adaptation which clearly demonstrates that long-term survival at zero-g is contraindicated. Instead of learning this basic lesson early, studies have focussed on finding more details of the degenerative process and trying to fix them with biomechanical means, rather than going the obvious step of building a spin-stabilised centrifugal gravity station that could be varied from 1g downwards and develop a much greater understanding of physiology vs gravity.