I don't know of you can speed up the time it takes for a pregnant sim to have their baby.
What I do know is how you get an alien baby. A male sim has to look through a telescope (as high as possible) and then wait...if you're lucky (or not, it's just how you look at it) he gets kidnapped by aliens, he returns, and is pregnant.

is it possible to get men pregnant with a girl alien? because so far the guy only had a boy.. and i was wondering if its possible to get a girl or if theres some cheat that can make it a girl??

yes, it is possible. here are the steps:
1. open the cheat code box (control, shift, C)
2. type in... boolprop testingcheatsenabled true
3. then hold shift down while clicking on a sim
4. click on spawn> tombstone of L and D
5. then while having whatever sim you want pregnant selected click on the tombstone and then click on either, "make me pregnant with...", or "make me alien pregnant"

***yes, you can get a male sim to get pregnant with this cheat***

to speed up a sims pregnancy, follow these instructions:

1. get the tombstone of L and D if you don't have it yet
2. have your pregnant sim selected
3. click on the tombstone and click on "speed up my pregnancy"

***it should take about 30 seconds - 1 min. in OUR time***

I HOPE I HELPED!!! :D :D

***P.S. i DON'T know how to get a sim pregnant with a specific gender....SORRY!!! :(

wait wats the tombstone of life and death??

They don't have anything to do with each other. Aliens have to do with the expensive telescope

I have tried everything its either my computor playing up or me doing it wrong;'( can u get a alien baby by using the xpensive telescope ??

hope u can help............please heeellllpp me !!!!!