How NOT to interact with pregnant co-workers

I started with my company straight out of college and was lucky enough to land a great group of co-workers with whom I have a lot in common. There are a lot of women in my office who are pregnant and/or have young children, and we share stories and commiserate regularly.

Pregnancy in the workplace is not exactly uncommon anymore. Logic would dictate that when you work in an office with a large number of women in their mid-twenties to mid-forties, there will be a lot of pregnancies. For whatever reason, some of the men in our office can't seem to grasp that concept. Every time someone announces a pregnancy, the "there must be something in the water" joke gets repeated so many times that it's all I can do not to say, "Is the water what's causing all of you guys to gain weight and turn gray? Because it sure seems to be happening to a lot of you."

The lame jokes are only the beginning. Below is my list of "Things Not to Say to Pregnant Co-Workers", based on comments from people in my office (and appropriate responses in italics):

General Irritating Questions
1. Were you trying to get pregnant? No, we meant to have anal sex but accidentally stuck it in the wrong hole.

2. Are you excited? No, actually we're considering late-term abortion but decided to make the announcement anyway.

Weight Comments
3. Wow, you're so big for 4 months. You're looking pretty chunky yourself.

4. How much weight have you gained so far? 1 million pounds

5. Your dress is still long enough in the front, but it's getting short in the back. GFY

General Comments
6. (In response to pregnant woman saying she's getting big or not feeling well) It's going to get so much worse. Thanks for your insight, Dr. Douchebag.

7. (In response to pregnant woman mentioning the sex of her baby) It's not sex, it's gender. Sex is what you did to make the baby. But I thought you told me a few months ago that I got pregnant from drinking the water?! Have you been lying to me all this time?

8. You shouldn't be eating/drinking that while you're pregnant. GFY

And, one post-pregnancy one:

9. (First day back to work) Don't you miss your baby?