My neighborhood is a tiny custom neighborhood that I used the DeleteAll Characters cheat on and started it with 30 sims.  Half I made playable, half are townies.  They have married and reporduced and are now entering the 3rd generation.  BUT, about 2/3 of the births are boys.  Since I started playing this neighborhood in August, I've only had 10 girls born from 33 births.  In the past few weeks, I've only had one girl and 6 boys!  Right now my town has a group of teenagers that only has 1 girl in it.  My boys are going to have to date and marry townies, I just know it!  Problem is, there's a very small selection of townies thanks to JMP.    I loathe townies, dormies, and the rest of those Maxis-made riff-raff!    My Sim-sons are too good for them!  LOL 

I know this is common and happens a lot.  I guress I'm just venting.  Or maybe someone knows an easy way to pick the sex of the baby while Mom is pregnant?  Or maybe give a male baby a sex change?  LOL  I tried with SimsPE once, but the baby kept tranitioning male anyway. 

Out of curiosity, do you save just before the birth occurs and then if you don't like the sex of the baby, exit without saving then reload and go through the process again?  And maybe again, and again, until you do get the sex you want?

This generally has worked for me - and did again last night when my Bisgrove newlyweds had their first child.  A boy, but I wanted a girl and after the second try, Claire was born.

What exactly causes this? I just started a new neighborhood a couple months ago and only 2 births out of 21 were male. Insane. I never reloaded because I wanted to see how carried away the game could get.

I heard it happens when one sex outnumbers the other in a hood, but how off balance can a new hood be? I only made 6 CAS's to start out, 3 male and 3 female.

It's a statistical effect of randomness. Each birth has, I'm assuming, a fifty percent chance of being male and a fifty percent chance of being female. This does not mean that half of your births will be female and half will be male (which is, for some reason, what most people think it means) but rather that, well, each birth has a fifty percent chance of being male (or female). It's the same principle behind coin-flipping (if you assume that you're flipping in such a way as to create a roughly 50% chance of either side landing up) -- if you flip a coin only ten times, you're very likely to come up with one result quite a bit more than the other, but if you flip a coin ten thousand times, your results would look a lot more even. It has to do with the population size -- if you have a larger population, you're less likely to have sampling errors.

Personally, I've never had that lack of gender balance in my game. In the short run, yeah, there's usually a bit of imbalance, but it has always corrected itself over time.

Sounds like an old simwife tale to me.  I am convinced it's simply random. It could also be that their random generator suck.  Not all software random generating routines are equal

Kristal why don't you just made yourself a bunch of new townies.  Or create a new family of roomates, put them on a empty plot with a phone and computer.  I spent something like 4 days trolling the net, looking for good looking sims to put into my game (lyran.net and MTS2 were my main source).  I don't just put them in my game. I extract the content of the file into a folder, load them up in BodyShop and remove all the custom content (they would be appalled seing all their hard work being discarded no doubt), replace them with default skin, hair and eyes (not Maxis) and then create them in CAS. 

Just think of it as immigration

For me, it seems that the closer it is to the birth time when I last saved, the more difficult it is to get the opposite sex.  If I last saved, say 4 to 5 sim hours before the impending birth, I seem to stand a better chance of getting the gender I want on my first reload.  But if my last save was within an hour or two before the birth, I may have to reload 5 or 6 times and STILL might not get the opposite sex.  So, from my experience, leave a little time between the last save and the time the baby is born.  I use the Insim to keep an eye on how many hours my sim is pg, and usually save when she/he is about 70 hours along.

And, of course, the lot debugger is essential for randomizing the attributes of the baby.  Once I found out how to use it, I can't have a pregnant sim who's close to birth do without it.  I had too many "clones" in my famililies before I started using it.

Probaby right, IgnorantBliss.  It just happened often enough and was really frustrating reloading over and over again trying for the opposite sex, so when I tried this and it worked I just stuck with it.  It may be a glitch in my game that's causing it, but I figured it was worth mentioning just in case it's happening to someone else.

My Ecological Gurus don't get paid vacation time for days they're pg that they wouldn't normally work, either, but it seems like everyone else's do!  So ... you never know ...

Just so you can have some pink nurseries, why not create a couple of CAS families with a couple of girl toddlers each?

Somehow I've found that custom hoods are weird where maids are concerned, I had one with two male maids (unusual) and one with no male maids.  I wonder why it seems to affect custom hoods?  when I moved Kaylynn into the game once, she was replaced by a female, so the balance of 2:1 in Pleasantview was maintained.

I've had times when I'd get all girls, and times when I'd get all boys.  This has resulted in second generation boys marrying and having children with third generation girls in my neighborhood.   

In my first Pleasantview, Kaylynn was replaced by a (ugly) male maid, though.

Maybe it's Maxis attempt to randomize?  so the balance of male:female is maintained, but not necessarily in the same game or on the same PC!

I pause and save the moment the sim goes into labour, then reload if the baby born wasn't of the sex I wanted. If it's still the same results after a few tries, I use the lot debugger, re-enter lot, let the labour proceed a couple of seconds from the last save, then pause and save the game again. Repeat if necessary. That usually worked for me before the new family member message pops up, and I've had the good fortune of not being stuck with a baby of the wrong sex and having to re-plan future marriages .