Question

If the menstrual cycle is of 35 days, then what is the risk period (cycle starts on $1^{st}$ day )?

• A. $9^{th}$ to ${17}^{th}$ days
• B. ${11}^{th}$ to ${18}^{th}$ days
• C. ${16}^{th}$ to ${24}^{th}$ days
• D. ${18}^{th}$ to ${35}^{th}$ days

Answer 1

The correct option is C ${16}^{th}$ to ${24}^{th}$ days

The risk period in the question refers to the time duration in which there are maximum changes of fertilisation and consequent pregnancy. In a normal menstrual cycle of 28 days, both LH and FSH attain a peak level in the middle of cycle (about 14th day). Rapid secretion of LH leading to its maximum level during the mid-cycle called LH surge induces rupture of Graafian follicle and thereby the release of ovum (ovulation). The ovulation (ovulatory phase) is followed by the luteal phase during which the remaining parts of the Graafian follicle transform as the corpus luteum. If the menstrual cycle is of 35 days duration, the LH and FSH will attain peak level in the middle of cycle around 16th or 17th day and hence ovulation should occur on 16th or 17th day. After which ovum shall be available in oviduct for fertilization for 24 hours. If sperms don't arrive then after 24 hours the ovum shall start journey towards uterus. Chances of conception will be maximum if there is sexual intercourse around the middle of menstrual cycle. Thus 16th to 24th day is called a risk period. Before this period there will be follicular phase and after ovulation there will be luteal phase.