Seasonality, Down's syndrome, anencephaly, and Turner's syndrome.
D000757:Anencephaly / Q000453:epidemiology*; D004314:Down Syndrome / Q000453:epidemiology*; D005260:Female; D006801:Humans; D010060:Ovulation; D012621:Seasons; D014424:Turner Syndrome / Q000453:epidemiology*