Which one of the following is the most likely reason of not occurring regular menstruation cycle in females?

Options

A. Fertilisation of the ovum
B. Maintenance of the hypertrophical endometrial lining
C. Maintenance of high concentration of sex- hormones in the blood stream
D. Retention of well-developed corpus luteum

Answer

A

Explanation

(a) If fertilisation occurs and foetus is implanted in the endometrium, the trophoblast cells of the developing placents secrete a hormone human Chorionic Gonadotrophic (hCG). This hormone like LH maintains the corpus luteum and the secretion of progesterone and estradiol by it. These two hormones check the breakdown of the endometrium of the uterus.The absence of menstrual bleeding is the earliest sign of pregnancy.