Of all the pretension and nonsese in art, music, and film I really think Von Trier is compeltely a genius. Outside of anything specific I would say Von Trier films convey emotion opposed to direct logic. Instead of only asking "what happend?" ask "how did that make you feel?". I know that is arrogant, but that is art.
On a slightly more specific level, pretty much all of Von Trier films convey quite horrible aspects of everyone's everyday reality. They all reflect the evil and confusion everyone more or less will interact and converse with. Some people will do it less directly, but it's not a periphery; it is still within their own souls. Others will directly consort and deal with the damaging aspects of the world. But whichever theme/movie you watch the issue is in all lives, not a (more or less) distant aspect of life.
Finally, Antichrist follows, essentially, confusions (sexual among many others) of a wife and mother. Perhaps at it's most basic, or astleast chronilogially first, she can't consolidate the relationship between her and her husband and her and her son. I really didn't agree with the hardcore cuts at first, but the fact they occur when the child is falling out the window (and she sees it while having sex) explains quite a lot.
I've heard some interpretations that it is a call for attention from her. For example, she puts the wrong shoes on her son to disform his feet so she has to take him to the doctor and receives sympathy. I think this is accurate, but I think a bit simple and here is where it seems as "women are evil" is the message.
Von Trier has stated this is not an attack on women; infact he identifies quite strongly with women. Ultimatly, none of this is quite distinct toward women except for the nature of the relationships. Men can have a similar effect, but it will be against men's social postion. Anticrhist and Gainsbourg's near sadism to her child and direct sadism to her husband reflects her inability to accomidate all four relationships between herself, her child, then finally her husband.
Not only did she fail then reject her individual and social position, she directly contradicted it. In Antichrist it was the man running and hiding inpotently from a crazed killer--a women and also his wife.
Most of Von Trier's films are from the position of a woman and I think rightly so. Not because a female point of view is less heard, but because of the social position it reflects both men and woman's point of view. One directly and one peripherally.