We know from past history and a few asides that there have been Aes Sedai, bound by the Oath Rod who married and had children. There was an Aes Sedai from past history who was used as an example of the extreme obedience the Tower expects from it's initiates - she married and had a child with a man she hated by the order of the Tower. Lan himself mentions to Nynaeve that "Aes Sedai marry as seldom as Wisdoms...", and Elayne herself doesn't think it would be considered shocking for her to be pregnant and an Aes Sedai. Yes, it is the overall culture that is against childbearing, for some very good reasons, but this is one case where little is said about this because it was really up to an individual Aes Sedai. She could very well marry her Warder, have children, retire or go into a voluntary retreat for 30-40 years to raise them, and then return afterwards. There is quite a lot that is implied but no specifically said - Aes Sedai have apparently run orphanages and done other charitable works requiring a lot of their time, but this doesn't really enter into a series about war and battle.

So I think this has more to do with the Aes Sedais' culture, as orius and others have said. The urge is there, but the women who tend to become Aes Sedai are also independent and not really given to being satisfied with being a wife or dealing with children.