Menstrual Cycling Continued - Ovulation
Last month we talked about the first half of the menstrual cycle. Now for the exciting part…
Ovulation is the most important part of the menstrual cycle, not just for fertility, but also for your hormonal balance!
As estrogen rises, the brain is triggered to release luteinizing hormone (LH) which causes an egg to be released from the ovary. The follicle remaining in the ovary becomes the corpus luteum which makes progesterone, a hormone important for maturing the uterine lining, calming the mind, reducing inflammation, regulating the immune system, and supporting healthy thyroid function, breast tissue, hair and skin. We need ovulation to make the progesterone.
How do we know if and when you’re ovulating? Signs can include:
Thin egg-white type discharge that can stretch 1” in length - this is the highway that can help sperm to travel if we’re trying to get pregnant
A small cramp on one side (Mittelschmerz) from the egg being released
Cervix changes - it softens, rises, and opens. This can be felt by inserting fingers into the vagina. Closer to menstruation, the cervix is harder and lower in the vagina.
A rise in basal body temperature of 0.5C a couple of days after ovulation for the rest of the cycle!
A positive ovulation predictor kit showing a surge in luteinizing hormone (this is not accurate for all women - especially in PCOS we might see higher LH throughout the cycle)
The luteal phase begins after ovulation. The follicle in the ovary that released the egg turns into the corpus luteum which makes progesterone. Progesterone peaks mid/late luteal phase (as long as ovulation occured) and then if no pregnancy occurs, the corpus luteum shrinks away and progesterone levels drop drastically.
The drop in progesterone is where many women will experience premenstrual symptoms such as cravings, breast tenderness, sadness, irritability, and anxiety. The drop in progesterone also signals the uterine lining to shed - bringing us back to menstruation.
The luteal phase is typically 12-16 days in length and is usually quite consistent in length from cycle to cycle, even if the total length of the cycle is longer than the average person or varies from month to month.