I opted for single bed room for both my pregnancy. I am someone who is afraid of staying in a cold room with low aircon temperature, so i requested to in a single bed room whereby i can adjust to the temperature that i am comfortable with.
If sharing room, you may have to expect lots of visitor from your room mate coming in n out and u may not be able to have full rest. But if you don't mind the crowd and cold room, you can opt for 2 bed room. Partly also can consider about the pricing of the bed, if i didnt remember wrongly, the price difference is not alot for single and 2 bed ward.