Your Menstrual Cycle: Ovulation and Menstruation
Every woman progresses through their menstrual cycle about once a month. This menstrual cycle continues throughout the child bearing years, until you reach menopause. The menstrual cycle includes the process of ovulation and menstruation that prepares your body for pregnancy. Some women, however, experience problems with their menstrual cycle, making it difficult to become pregnant. Your reproductive endocrinologist can help to determine if your menstrual period is contributing to your fertility issues.
What is the Menstrual Cycle
Your menstrual cycle refers to the natural cycle of ovulation and menstruation that occurs every month in women of chilbearing age. It is what allows women to become pregnant in the first place - without the menstrual cycle none of us would even be here right now. You may have heard that the average menstrual cycle lasts about 28 days, but actually, the length of your cycle depends on your own body and health. Menstrual cycles can last anywhere between 21 and 35 days. The first day of your menstrual cycle coincides with the first day of menstrual bleeding, while the last day of your menstrual cycle comes just before your next menstrual bleed.
Hormones Involved in the Menstrual Cycle
There are a variety of hormones involved in regulating your menstrual cycle. These include:
- Follicle Stimulating Hormone (FSH) : FSH is a hormone produced by your pituitary gland, a tiny organ found inside of your brain. FSH helps to encourage follicles to form and eggs to be released. It also stimulates estrogen production within the body.
- Luteining Hormone (LH): LH is a hormone involved in stimulating ovulation and follicular development. LH also helps with the development of the corpus luteum.
- Estrogen: Estrogen is one of the main female sex hormones. It is produced by the ovaries and breasts and by other areas of the body. Estrogen plays a vital role in egg growth.
- Progesterone: Progesterone is produced by the corpus luteum, after ovulation has taken place. Progesterone helps to prepare the endometrial lining for possible pregnancy.
Stages in the Menstrual Cycle
The menstrual cycle is made up of several distinct stages. These stages all contribute to overall fertility and pregnancy.
The First Days of the Menstrual Cycle
The menstrual cycle actually begins with the first day of your period. During this time, estrogen levels in your body are extremely low. This signals your body to produce FSH. As the levels of FSH in your bloodstream rise, approximately 20 follicles inside of your ovary begin to mature. One of these follicles will begin to secrete estradiol, a type of estrogen, while the weaker follicles die off. As your period ends, your body will prepare for ovulation by creating a thicker uterine lining, appropriate for implantation. Your cervical mucus will also change, from thick and clumpy, to thin and slippery.
Ovulation occurs around the 14th day of your menstrual cycle. During this time, estrogen begins to rise rapidly, peaking about a day before ovulation. As your estrogen levels peak, your body will experience a surge in LH, triggering your ovaries to release an egg from its follicle. This egg will enter one of your fallopian tubes and travel towards your uterus. The leftover egg follicle gradually shrinks, becoming the corpus luteum. The corpus luteum secretes progesterone, helping to prepare your uterine lining for pregnancy.
If your egg is not fertilized after ovulation, your body will progress into the menstrual phase of its cycle. During this stage, the unfertilizied egg is expelled from the vagina along with the uterine lining. This is your menstrual period. Typically, menstruation lasts between three and seven days, though it can last as long as ten days. Your menstrual blood may change in color, ranging from bright red to deep brown. You may also notice some small clots in the blood. This is because your menstrual fluid is actually comprised of various cells and tissues. During menstruation, hormone levels drop, signalling the cycle to start all over again.
Problems with the Menstrual Cycle
If you are facing fertility difficulties, you may be experiencing problems with your menstrual cycle. Your health care provider can offer you different tests or exams to help find out if you are experiencing any menstrual cycle complications. Common menstrual cycle complications include:
- Oligomenorrhea: Oligomenorrhea, or irregularity of the menstrual cycle, occurs when you when don't get a menstrual period every month. This can indicate problems with ovulation or hormone production, and may interfere with pregnancy.
- Amenorrhea: Amenorrhea refers to the complete loss of menstruation. This can occur for a variety of reasons, particularly hormone imbalance. If you are suffering from amenorrhea you may not be ovulating regularly, making it difficult to become pregnant.
- Anovulation: Sometimes, women can experience regular periods but may still have trouble getting pregnant. This could signal a problem with ovulation. Anovulation occurs when you don't ovulate regularly or when your body doesn't ovulate at all.