Why cant hydrocortisone cream be used on pregnant women?

me and my wife are expecting our first baby ...my wife has this unstoppable itchyness feeling in some parts of body, we went to her physician and had recommeded this cream , which iam not really sure if it is oke to apply for my wife.. any doctor here.. thanks..|||I am not a Dr, but used to have eczema and used this cream, reason for not using it could be that it has a steroid base, ask a midwife to recommend another cream