When are Women and Men Most Fertile During the Menstrual Cycle?

When are Women and Men Most Fertile During the Menstrual Cycle?

Did you know there is only a limited time in each menstrual cycle when it’s possible to get pregnant? This is known as the fertile window. The highest pregnancy rates are in couples who have intercourse every one to two days. Regular intercourse every two to three days after the end of your period can make sure intercourse occurs during the fertile period and semen quality is optimal.

When are Women Most Fertile?

Women are most fertile six days of the menstrual cycle: the five days prior to ovulation and the day of ovulation.

To understand your fertile window, it is important to understand what is occurring through each phase of your menstrual cycle. The menstrual cycle occurs in four stages.

Menstrual Phase: Day 1-up to or over 7 days

  • Menstruation may last from 3 to 7 days and it is the sloughing of the thickened endometrium through the cervix and in to the vagina.

Follicular Phase: Day 1-14

  • The follicular phase begins on day 1 of menstruation and lasts up until ovulation. Follicle Stimulating Hormone (FSH) stimulates the ovary to recruit the follicles that contain the developing eggs.

Ovulation Phase: Day 10-16

  • During the follicular phase, one and occasionally two follicles will mature. Estradiol levels rise, thickening the lining in the uterus to prepare for the implantation of the embryo. Cervical mucus increases and becomes clear and stretchy.
  • LH levels rise dramatically. Ovulation occurs 36 hours after the LH surge when the mature egg is released from the surface of the ovary. This usually occurs two weeks before the next period.
  • The egg is moved through the fallopian tube by tiny hair-like projections. The egg reaches has a 24-hour window to meet a viable sperm.

Luteal Phase: Day 16-28

  • After ovulation, the follicle develops into the corpus luteum. The corpus luteum releases progesterone. Progesterone stimulates the thickening of the uterine lining, preparing the uterine lining for implantation.
  • If conception does not occur, LH decreases and the corpus luteum will gradually produce less estradiol and progesterone. Approximately 14 days after the LH surge, the uterine lining sloughs, and menstruation begins. The FSH levels begin to rise, and the next cycle begins again.

If the egg becomes fertilized by the sperm, it implants in the endometrium several days after ovulation. The early embryo makes hCG and the hCG maintains the corpus luteum and progesterone production.

When are Men Most Fertile?

Men do not have a “fertile window”. Sperm is continually produced and stored in the testes. Healthy sperm is viable anytime under normal health circumstances. Sperm can live for up to six days in the reproductive tract.

Studies indicate that optimum semen quality, measured in terms of motility, morphology, and total sperm count, occurs when there are two to three days between ejaculation. Longer intervals are associated with lower pregnancy rates.

To learn more about this topic and speak to one of our physicians about fertility treatment, you can request a consultation here.



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