McDonald’s ‘Seven Sexy Cowboy Robots’ from Strange Horizons was collected by Strahan in his Year’s Best Volume 5 (Best SF Review with link to online story here).
The story starts as if it is going to be a light-hearted look at sexbots, as Alina, one of the early 7832BNX7 series, is overhauled before being implanted with a fetus that she will carry to term as a surrogate. We follow her through two such pregnancies, returning base to have memories wiped and other parts cleaned and tested. Then the story suddenly gets darker, and colder, and Alina has to draw on the various resources programmed in to her, and to bring to term the baby inside in circumstances altogether outside of her programming and decision-trees. The story ends begging for a sequel.