[pavel_lishin]

There is a lot of pressure on women to have children, though, and having kids drastically changes how, when, and with whom you socialize.

To elaborate, in case you don't have kids: for the first several months, you're likely exhausted and don't even want to socialize. If you do, you're still limited due to time - young children just sleep and eat, and you're bound to their schedule. If you're exclusively breastfeeding, you can't drive an hour out to see a two hour movie with your friends, because your kiddo's feed is going to fall within that timespan.

Once they get older, you can go out again, but you're not going to necessarily be doing the same things you wanted to earlier. Being woken up hungover by a screaming baby at 5am is terrible, so you're going to cut down your social drinking. Going camping on the weekend is more difficult, too - you're leaving your partner in the lurch. Spur of the moment plans are difficult, too - you're still tied to your kid's schedule, and there are places where it is difficult to take a small child. ("You wanna go rock climbing?" "Yes, but...")