Unlike the male function, which is characterized by the production of sperm throughout a man’s life from puberty onwards, we’re born with a specific quantity of follicles in each ovary: the ovarian stock or ovarian reserve.
The Functioning Of The Ovarian Reserve
The follicles appear in the 5th month of a woman’s life in utero. There are then 5,000,000 to 7,000,000 million of them. The number of follicles then gradually decreases to around 600,000 to 2,000,000 at birth.
At puberty, your reserve stabilizes at 400,000 follicles at the beginning of the menstrual cycle (menarche).
Throughout your life, at each menstrual cycle, the ovaries will use several follicles to select the dominant follicle. This consumption of follicles will cause the stock to grow:
- 25,000 follicles at age 38,
- 10,000 follicles at 40
- Fewer than 1000 follicles at the menopause.
The notion of ovarian reserve allows a better understanding of the hormonal cycle and the menstrual cycle’s evolution during the life of the woman. By the variation of hormones, and notably by the progressive decrease of the follicles, of the progesterone secretion at first (luteal insufficiency) then of estrogen at a second time.
The decrease in ovarian reserve is also responsible for a decrease in fertility, particularly after the age of 37. Quantification of the ovarian reserve can be carried out by ultrasound with the count of CFA antral follicles (measured between the 3rd and 5th day of the cycle). The FSH level (increases with the decrease in ovarian reserve), and the AMH level (anti-Müllerian hormone secreted by the follicles, decreasing with ovarian reserve). These indicators can be used to study female fertility.
Your Temperature Curve: An Indicator of Ovulation
Measuring your body temperature in the morning before you get up allows you to identify the temperature shift due to ovulation.
This is because on the day of ovulation, your basal body temperature rises by 0.5 °C due to the secretion of progesterone during the luteal phase. This simple method allows you to track your ovulation and the regularity of your cycles. It can also be used as a natural contraceptive method.
Fertile period or fertility period: how to observe it?
The most fertile period is between 72 hours before ovulation and 48 hours after ovulation.
This is a fairly short period, which also corresponds to the sperm vitality inside the uterus. The calculation of this period therefore depends on the regularity of your cycles. It can be determined by ovulation tests and by monitoring your temperature curve.
Luna helps you:
The Fertility Tracker allows you to access your fertility potential according to your age for information purposes, and to track your fertility period according to your menstrual cycle. You can also record your temperature readings within LUNA.
Co-authored and scientifically validated by Dr Jean-Philippe Estrade,
Gynaecological surgeon and endometriosis expert at the Clairval Private Hospital and the Bouchard Clinic in Marseille.