* use a questionnaire that mixes abortions, which cause cancer, with miscarriages, which typically do not, but referring to both as "abortion"<ref>See, e.g., [[Harvard abortion study]]</ref> | * use a questionnaire that mixes abortions, which cause cancer, with miscarriages, which typically do not, but referring to both as "abortion"<ref>See, e.g., [[Harvard abortion study]]</ref> |