I think there's another reason thats gone unstated. The Soviet Union imported Cultural Marxism to the west, but now Russia is rejecting Cultural Marxism for itself having felt its devastating effects.
Not only are they dialing back on abortion, but also on issues like gay marriage and gay adoption. Putin is not having it and he's jailing the cultural anarchists who lobby for such measures.
That said, with America embracing gay marriage and gay adoption, the latter pretty much going unchallenged, it stands to reason Putin, who is steadfastly against such arrangements, would look for reasons to limit Russian adoptions for Americans.
Its sad to say, but at least in part Russia now views America has too decadent for Russian children.