In 2016, scientists published two studies regarding human embryos developing for thirteen days within an ecto-uterine environment.[3][4] Currently, a 14-day rule prevents human embryos from being kept in artificial wombs longer than 14 days. This rule has been codified into law in twelve countries.[5]
So there's your answer; Suppressed.
Also mentioned in that article is this comedy;
In the 1970 book The Dialectic of Sex, feminist Shulamith Firestone wrote that differences in biological reproductive roles are a source of gender inequality. Firestone singled out pregnancy and childbirth, making the argument that an artificial womb would free "women from the tyranny of their reproductive biology."[25][26]
I'm gonna go out on a limb and say that she is radically underestimating the scope of what it would free them from.
We would have artificial wombs within 10 years if there were sufficient motivation.
It's either that technology is being suppressed and we'd have it already if not, or it won't be possible for decades.
There's no in-between in my opinion.
From the wikipedia article on artificial wombs
So there's your answer; Suppressed.
Also mentioned in that article is this comedy;
I'm gonna go out on a limb and say that she is radically underestimating the scope of what it would free them from.