Letter: Changing from a high- to low-dose oral contraceptive.
D003276:Contraceptives, Oral / Q000008:administration & dosage*; D003280:Contraceptives, Oral, Synthetic / Q000008:administration & dosage*; D004997:Ethinyl Estradiol / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D010060:Ovulation; D011374:Progesterone / Q000097:blood
D003276:Contraceptives, Oral; D003280:Contraceptives, Oral, Synthetic; D004997:Ethinyl Estradiol; D011374:Progesterone; D007986:Luteinizing Hormone