Medical Contribution by Stephanie Beall, M.D., Ph.D.
One in eight couples will experience infertility, defined as the inability to conceive after six months to a year of trying depending on the female partners age. Many of the causes behind infertility leave no clues until testing has been completed, except for one: the regularity of a woman’s menstrual cycle.
The menstrual cycle is directly related to ovulation (the release of an egg). But what if ovulation isn’t occurring, how do you know and what can be done to help? Understanding your menstrual cycle could open a window offering important insight into the factors central to conception.
Understanding Your Menstrual Cycle: It’s more than just your period.
The menstrual cycle is a series of changes a woman’s body goes through each month whereby the ovary releases an egg and the uterus prepares for pregnancy. The menstrual cycle includes two phases: the follicular phase and the luteal phase.
Phase One: The Follicular Phase
During the follicular phase, the hypothalamus and pituitary glands in the brain release a hormone known as follicle stimulating hormone (FSH). FSH stimulates the development of a follicle, which is a tiny fluid-filled sac within the ovary containing a maturing egg. The follicle also secretes estrogen, which produces mid-cycle changes in the cervical mucus and stimulates the lining of the uterus to thicken. These changes help prepare the uterus to receive the embryo. The follicular phase starts on day one of your menstrual cycle, the first day of day of your period, and concludes around 13 days later.
Phase Two: The Luteal Phase
The start if the second phase, or luteal phase, begins with ovualtion. There is a drastic surge in luteinizing hormone (LH), also released by the pituitary gland, causing the follicle to break open and release the mature egg into the Fallopian tube. During her reproductive years, a woman usually releases a single mature egg each month, in a process known as ovulation.
Cervical mucus is most receptive to sperm around this point in the cycle and a woman has the best chances of conceiving leading up to and during ovulation. When a couple has intercourse around the time of ovulation, sperm swim through the cervical mucus, into the uterus and along the Fallopian tube, where they meet the egg. The egg has the capacity to be fertilized for about 24 hours after it is released from the follicle.
Once ovulation occurs, the follicle that produced the egg becomes a functioning cyst called the corpus luteum. The corpus luteum produces progesterone, which prepares the lining of the uterus for implantation of the fertilized egg resulting in pregnancy.
If fertilization does not occur, the egg passes through the uterus, and the corpus luteum ceases to function on about 14 days after ovulation. The uterine lining then breaks down and is shed several days later as the next menstrual cycle begins.
Is there such a thing as a normal menstrual cycle?
There is such a thing as a normal cycle. The menstrual cycle is essential for the maturation and ovulation of an egg in addition to the preparation of the uterus for implantation. A normal menstrual interval ranges from 21 to 35 days and indicates that a woman is likely ovulating regularly. The portion of the cycle where the uterine lining is shed, also known as the period, in a normal cycle lasts between 2 and 7 days. If there is very little bleeding during the period (less than 2 days or very scant amount) or the bleeding lasts for greater than 7 days then it may indicate an abnormality within the cavity of the uterusor irregular ovulation.
What does it mean if the number of days in the menstrual cycle or between periods has increased?
If the cycle length is still in the normal range described above (between 21 to 35 days) then the change is likely normal variation. However, if the cycle extends beyond 35 days, the cycle might be considered irregular raising concerns as to whether or not ovulation is occurring since longer cycles are caused by a lack of regular ovulation.
During a normal cycle, it is the fall of progesterone that brings upon bleeding. If a follicle does not mature and ovulate, progesterone is never released and the lining of the uterus continues to build in response to estrogen. Eventually, the lining gets so thick that it becomes unstable and like a tower of blocks, eventually falls and bleeding occurs. This bleeding can be unpredictable, and oftentimes very heavy and lasting a prolonged period of time.
How can I time my ovulation?
It is a common misconception that the luteal phase begins around day 14 of your cycle; in fact, it can more easily be determined by counting 14 days prior to the start of your cycle. The length of a normal cycle is anywhere between 21 and 35 days, so if you are counting from the start of the cycle you may be missing the time of ovulation by as much as a week. To calculate when ovulation is likely to occur determine how long your cycle lasts and subtract 14 days from the predicted end of the next cycle. Another option is to use an at home urine based ovulation predictor kits. These tests look for the surge of luteinizing hormone (LH) which occurs a day to two days prior to ovulation.
If I am not ovulating, what might be the cause?
There are many causes of anovulation, the medical term used to describe when ovaries do not release mature eggs on a regular basis. Irregularities with the thyroid gland or elevations of the hormone prolactin can disrupt the brain’s ability to communicate with the ovary and result in anovulation. In addition, polycystic ovary syndrome (PCOS), a syndrome caused by imbalanced sex hormones, can also cause failed ovulation. Not only do these hormonal imbalances lead to problems with ovulation and therefore fertility, but they may also increase the risk of miscarriage.
What should I do if I don’t think I am ovulating?
Irregular or no ovulation makes conception very difficult without intervention. If you do not have a normal monthly menses, no matter the amount of time you have been trying to conceive, you should be evaluated by your OB/GYN or a fertility specialist. The first step will be a basic work-up including blood work at the start of the cycle. The results can help your physician better understand what may be causing your irregular cycle and what options are available to help you and your partner conceive.
If you are having trouble conceiving, a fertility work-up may help determine if you are ovulating or if there are other factors. Shady Grove Fertility’s team of dedicated New Patient Liaisons are available to answer your questions and schedule a consultation with a physician. Call 877-971-7755 or click to schedule an appointment.