title: Relationships in medicine--causal vs. casual.
authors.forename: A
authors.initials: A
authors.lastname: Pellicer
authors.forename: C
authors.initials: C
authors.lastname: Simón
mesh_terms: D006063:Chorionic Gonadotropin / Q000009:adverse effects; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D016471:Ovarian Hyperstimulation Syndrome / Q000150:complications*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000209:etiology*; D018873:Pregnancy Rate
chemical_list: D006063:Chorionic Gonadotropin