title: Problems in conducting prospective surveys.
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000209:etiology; D000013:Congenital Abnormalities / Q000209:etiology*; D005260:Female; D005602:France; D006306:Health Surveys; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications / Q000188:drug therapy; D011446:Prospective Studies