For PR purposes, they claim to be for "family planning" and women's health, but their main interest is promoting abortion (and making lots of money in the process).
(In response to another poster) I believe that, although they do not gain directly by promoting the gay agenda, it's part of their (very successful) strategy of breaking down traditional moral values.
You know what? Those folks were right!! That method works every time it's tried! Seriously though, Planned Parenthood was begun in the early parts of this century in the US by folks who were appalled at the number of children the immigrant populations were having. They were concerned that those 'mongrel' families would overrun the US. If you read any early works of Margaret Sanger, (the founder of PP) you'll see she was heavily into creating a better society through breeding. That's why she's called "The Father of Modern Eugenics". PP advocated no more than 2 children per family and got a huge following among Protestant folks. The Catholics didn't catch on until the 70's and then because of the squishiness of some priests on artificial contraception, but I've noticed many young Catholic families lately and they don't seem to be holding to that 'two child' idea anymore.
There are VERY effective methods of Natural Family Planning that don't involve chemicals or barriers, but most folks just don't know about them because outside of the Catholic Church they don't seem to be well publicized. Surprisingly though, I saw a flier for Natural Family Planning in my HMO a few weeks ago! It is good to know the word is getting out!