The Menstrual Cycle (Menstruation Cycle)

This video, titled "The Menstrual Cycle (Menstruation Cycle)" by Gynae Consultant, explains the biological processes driven by fertility and pregnancy throughout a typical monthly cycle:

The Ovaries and Initial Egg Development

• Ovarian Reserve: The ovaries contain a finite number of eggs stored in tiny sacs called follicles.
• Early Phase: At the start of the menstrual cycle (the first week), about five eggs in each ovary begin to develop and mature into antral follicles. Doctors often check this phase via ultrasound or blood tests (FSH and Anti-Mullerian Hormone) to evaluate ovarian reserve and fertility.
• Selection: By roughly day seven, the body selects one dominant follicle to continue maturing, while the remaining recruited eggs regress and disappear.

Ovulation and the Second Week

• Release: The dominant follicle grows through the second week. Around the middle of the cycle, the egg is released from the ovary into the fallopian tube (ovulation).
• Potential Fertilization: If a sperm meets and fuses with the egg in the fallopian tube, fertilization occurs. The resulting embryo then travels down to implant itself into the lining of the womb to establish a pregnancy.

The Role of the Corpus Luteum

• If Pregnancy Occurs: The empty follicle sac seals itself to become the corpus luteum. It begins producing progesterone, a crucial hormone that keeps the womb lining thick and healthy to support the pregnancy.
• If Fertilization Fails: The corpus luteum regresses and disappears. Without the necessary hormones to support it, the lining of the womb sheds, resulting in menstruation, which restarts the entire cycle.