(v2.0 only) pregnancy.reseed girl/boy/any - Change pregnancy, see reseed options below.
pregnancy.scan nogender - Reveal number of babies (single, twins, triplets) without revealing gender. Commands pregnancy.scan - Reveal number of babies and genders. The cheat console will tell you whether the Sim is pregnant, and the number and gender of babies.
Open the cheat console by pressing CTRL-SHIFT-C