Which of the Following Is the Most Common Cause of Iron-deficiency Anemia in Pregnancy

Mrs. Prieto, a 30-year-old Pregnant Woman, Comes to the Clinic for Her Prenatal Check-up. She Complains of Fatigue, Weakness and Shortness of Breath. Upon Assessment, the Nurse Notes Pale Conjunctiva and Brittle Nails. the Doctor Suspects Iron-deficiency Anemia