The hormone detected by a standard urine pregnancy test is
- A. luteinising hormone
- B. follicle stimulating hormone
- C. progesterone
- D. human chorionic gonadotropin
Explanation
The chorion of the young embryo secretes hCG, which keeps the corpus luteum alive so that progesterone continues and the endometrium is not shed. Because only a pregnancy produces it, hCG is specific, whereas progesterone is high in the luteal phase of every cycle and so would give false positives. It appears in urine within about two weeks of fertilisation.