Hi & Welcome.
I can understand your concern regarding the safety of medicines for itching during pregnancy.
Itching is one of the most common skin problems in pregnancy causes for which include specific
dermatoses of pregnancy to various skin conditions such as
atopic dermatitis, urticarial (allergic), infections,
cholestasis, & infestations or drug induced. In addition to these, various systemic diseases can also manifest with itching.
Calosoft (calamine) lotions is a skin protectant, effective for soothing and protecting the skin following itching, pain, and discomfort.
Since it is applied topically (locally) on the affected areas of the skin, it does not gain access to blood circulation and hence safe to be used during pregnancy.
If itching is not relieved by the Calosoft lotion, oral antihistamines like
Promethazine or
Hydroxyzine or Desloratidine which are safe during pregnancy can be useful.
However, the cause of itching must be found by doing certain lab tests like CBC, Absolute eosinophilic count, Liver function tests, etc.
Hope the suggestions given could be useful.