Is a woman, divorced by her husband while she was pregnant, and he then claimed to have taken her back without returning her to his home or resuming marital relations with her, still considered his wife after giving birth and the completion of her iddah (waiting period)?

If the husband contacts his wife and explicitly states his intention to take her back (raj‘ah) before she gives birth, the raj‘ah is valid, and she returns to his marital bond, becoming his wife legally, provided that he had not divorced her fundamentally before, or had divorced her only once.