No! Orgasms and ovulation are unrelated. In order to ovulate, estrogen gradually builds up, usually over a period of days. Orgasms can occur at any time in the cycle, thank goodness!
FERTILITY AND CYCLES
WHAT PERCENT OF A WOMAN’S CYCLE IS FERTILE?
The answer to this question is somewhat tricky. The general answer is that most women are fertile for only a few days per cycle. However, there are several factors to consider:
1.The woman’s egg can only live up to 24 hours. Two or more eggs may be released over a maximum of 24 hours. So, in a vacuum, a woman is fertile for only about a day or two. But the man’s sperm can live up to 5 days, so the combined fertility of the two individuals is about a week.
2.For a couple trying to get pregnant, the woman’s fertile phase is only as long as she has fertile-quality cervical fluid preceding ovulation. That might be several days, or less than one.
3.For a couple trying to prevent pregnancy, FAM adds a buffer zone of a few days on both sides of her fertile phase to assure that an unplanned pregnancy does not occur. This usually amounts to about 8 to 10 days per cycle.
WHAT ARE YOUR CHANCES OF CONCEIVING IN ANY GIVEN CYCLE?
It is believed that the average fertile couple who does not chart has about a 25% chance of conceiving for any given cycle, depending on their age, frequency of intercourse, and numerous other factors. Of course, if couples are taught precisely when to time intercourse based on when the woman is most fertile, those odds can be greatly increased.
CAN A WOMAN GET PREGNANT DURING HER PERIOD?
The answer lies in the wording of the question. More precisely, it’s essentially impossible for a woman to conceive during her period, but on rare occasions it’s possible for a woman to get pregnant from intercourse during her period. Note the difference in the two statements.
Since sperm can live for five days, a couple could have sex near the end of the woman’s period, and the sperm could then live long enough to fertilize an egg several days later, if the woman had a very early ovulation. (Conception is more likely in these cases if intercourse occurs at the end of a 6- or 7-day menstruation.) It’s also possible that women who think they got pregnant from intercourse during their period were actually having sex during ovulatory spotting.
IS IT TRUE THAT A WOMAN CAN GET PREGNANT ANYTIME?
No, it’s not. A woman can only get pregnant from intercourse while she has fertile-quality cervical fluid present, the few days surrounding ovulation. In addition, while ovulation can vary from cycle to cycle, once a woman ovulates, she cannot ovulate again for the remainder of that cycle.
CAN A WOMAN GET PREGNANT IF SHE HASN’T BEEN MENSTRUATING?
Yes, but certainly not as likely as the average woman. Since a woman releases an egg 12 to 16 days before menstruation, it’s possible to get pregnant without actually having periods. Thus, women who are not menstruating for whatever reason (excessively low body fat, breastfeeding, being premenopausal, etc.), are always at risk of impending ovulation. This is because the underlying condition causing the lack of menstruation could change, thus unexpectedly triggering the release of an egg.
The bottom line is that women who don’t menstruate cannot count on their condition as reliable contraception. In fact, the only practical way to know if ovulation is approaching is through charting your cycles, and more specifically, observing the changes in your cervical fluid.
Of course for those couples desiring to get pregnant, the reality is that you will definitely want to resolve the underlying problem preventing menstruation. Until you do so, your chances of conception will be very low, as discussed in Chapter 7.
CAN YOU HAVE A CYCLE IN WHICH YOU DON’T OVULATE BUT YOU STILL GET YOUR PERIOD?
The quick answer is, “Yes, sort of.” But the more enlightening and biologically correct answer is that if you fail to release an egg, the bleeding you experience will be what is referred to as anovulatory bleeding. The distinction is this: Technically speaking, a period is the bleeding that occurs about 12 to 16 days after the release of an egg. So, if no egg is released, it is not really a period that follows, but anovulatory bleeding.
There is a huge difference between cycles in which the woman ovulates but does not get her period, and one in which she gets her period but does not ovulate. What is that difference? In the former case, the woman is almost certainly pregnant! In the latter case, she has had an anovulatory cycle.
HOW DOES THE PILL WORK?
In essence, the Pill works by manipulating the normal hormonal feedback system. The end result is that the body doesn’t release the hormones necessary to stimulate the ovary to release an egg. As a backup, several other facets of the woman’s reproductive system are also altered. The cervix is prevented from producing the fertile-quality cervical fluid necessary for sperm movement and survival, and the uterine lining is obstructed from producing a rich site for egg implantation.
CAN STRESS AFFECT YOUR FERTILITY?
The role that stress plays on one’s fertility is fairly complex. Stress itself is not believed to prevent conception. However, it can delay ovulation by suppressing the hormones necessary for ovulation to occur. If a couple trying to get pregnant adheres to the myth of ovulation always occurring on Day 14, they may then inadvertently prevent pregnancy by timing intercourse on the wrong day, thus triggering a vicious circle of misperceived infertility causing more stress. Charting her cycle would allow the couple to regain control by correctly identifying the woman’s fertile phase.
HOW MANY DAYS CAN SPERM SURVIVE?
Sperm can generally survive a maximum of 5 days in the fertile-quality cervical fluid that women produce around the time of ovulation. It is much more likely that sperm will survive a maximum of 3 days, and only a few hours in dryer, less fertile types of cervical fluid. If there is no cervical fluid present, the sperm will usually die within a couple of hours.
HOW LONG CAN A HUMAN EGG SURVIVE?
Most ova survive about 6 to 12 hours after ovulation. However, for the purposes of contraception, the Fertility Awareness Method assumes a 24-hour survival period, plus an additional 24 hours in case there is a multiple ovulation.
WHAT SHOULD I LOOK FOR NOW THAT MIGHT HELP IDENTIFY A POTENTIAL FERTILITY PROBLEM IN THE FUTURE?
If you plan to get pregnant someday and experience any of the signs listed below, you should consult with your physician to rule out any possible conditions that may require treatment. These problems are discussed throughout the book, and can be referenced in the index:
•anovulation
•intense menstrual cramps
•short luteal phases of less than 10 days
•more than two days of premenstrual spotting or postmenstrual brown bleeding
•irregular or no cycles, often accompanied by extra weight, acne, excess body hair, and excessive fertile-quality cervical fluid
APPENDIX C
The Menstrual Cycle: A Summary of Events Through the Use of the Proverbial 28-Day Model
The main text of this book provided a brief overview of how the female reproductive system works. Still, I believe it’s worth taking a few pages here to give a somewhat more detailed description of the typical menstrual cycle. For those of you who have often wondered how and why your body does what it does, this summary can offer a more complete introduction to the topic. Should you find it interesting, I would encourage you to explore a more thorough discussion of the subject in biology and medical texts, especially if you experience gynecological conditions that stray considerably from the norm.
Like so much in nature, your body is a highly complex system of continuous feedback loops. If they are functioning smoothly, the menstrual cycle’s hormonal influences will ultimately create an intricate self-correcting thermostat. Of course, the principle goal of the system is a much more ambitious project than keeping a room at 72 degrees. Every cycle, your body works to produce an egg capable of being fertilized, and the conditions necessary to nurture it for the duration o
f a pregnancy.
In order to explore how this happens, I’ll take the prototype 28-day cycle and analyze the hormonal developments that occur in chronological progression. I will also overlay the major fertility signs so that you can review how the pieces all fit together. Of course, please remember that what will follow is a description of a perfectly functioning 28-day cycle, but as you certainly know by now, what is 28 days for Jane Doe may be a completely normal 21 to 35 days for you. In fact, studies show that less than 15% of cycles are precisely 28 days, and it’s equally rare for ovulation to occur on exactly Day 14.*
THE KEY HORMONES
Before beginning, let’s review the primary function and sources of the five most important female hormones. While your reproductive system has more than a dozen hormones, these are the five key ones that I think women should know. They are:
1. Follicle Stimulating Hormone (FSH): The hormone most responsible for the initial development of a select few follicles each cycle. Under the influence of FSH, a dozen or so follicles evolve from tiny and immature (antral and primordial) to relatively large and partially matured (vesicular). As this occurs, the eggs within each follicle gradually approach the capacity to be ovulated. FSH is produced in the anterior part of the pituitary, but absorbed by FSH receptor cells on the follicular wall. The pituitary is a gland at the base of the brain located between the brain stem and the hypothalamus. There is little FSH in the system as menstruation begins.
2. Estrogen: The most potent of the three main types of estrogen is estradiol, the type that is produced by the follicles that develop within your ovaries as you progress from menstruation to ovulation. Each cycle, it is responsible for maturing eggs and the uterine lining as well as developing a wet, fertile-quality cervical fluid as you approach ovulation. In addition, it’s responsible for promoting the maturation of female sex organs as well as secondary sexual characteristics. There is very little estrogen in your system as a new cycle begins.
3. Luteinizing Hormone (LH): The other major hormone produced in the anterior pituitary, LH is responsible for both stimulating and completing follicular growth (with FSH), as well as the luteinization of the ruptured follicle in order to transform it into a corpus luteum following ovulation. LH is best known for the “LH surge,” that dramatic increase in LH production that serves as the immediate trigger to ovulation, which follows a day or so later. Together, FSH and LH are called the pituitary or gonadotropin hormones. There is little LH in the system as menstruation begins.
4. Progesterone: The heat-producing hormone primarily manufactured by the corpus luteum, following ovulation. It is the hormone most responsible for nurturing and maintaining the endometrium in the postovulatory phase. As you have learned, the corpus luteum is the follicular body on the interior of the ovarian wall that is left behind by the ovulated egg. The immediate cause of menstruation is the cessation of progesterone production, triggered by the disintegration of the corpus luteum a couple of days earlier.
5. Gonadotropin Releasing Hormone (GnRH): The hormone produced in the hypothalamus, which, when secreted, causes the anterior pituitary to increase production of the gonadotropin hormones, specifically FSH and LH. The hypothalamus is located just above the pituitary, and essentially forms the floor and lower walls of the brain. It’s for this reason that some speculate stress and other environmental factors can play havoc with the length of menstrual cycles. It is believed that stress directly affects the hypothalamus and its manufacture of GnRH, which in turn changes output of FSH, LH, and so on down the cyclical line.
Knowledge of GnRH is somewhat more speculative than that of the other hormones. This is because it is harder to monitor since it operates between the hypothalamus and pituitary within the brain. It is known that it’s released in pulses that last about an hour or so, and that various experiments have shown that it is indeed these GnRH pulses that stimulate FSH and LH production within the anterior pituitary. However, there is still some uncertainty as to the intensity and timing of GnRH production within the hormonal system. (It is for these reasons that GnRH is not charted on the graph in the color insert.)
THE ROAD TO OVULATION
Day 1 of any cycle is the first day of menstruation. As you’ve learned by now, it is hardly the most important day, for that distinction belongs to the day of ovulation. Yet for women the world over, it certainly is the most noticeable event. The majority simply accept their menstrual fate, and some (though I suspect not most) have even learned to celebrate it. In any case, why the bleeding, and why now?
As with any recurring cycle, you can’t simply pick a given day, call it the first, and then explain what is going on, without at least acknowledging that what happens on Day 1 is a direct result of what happened on the last days of the previous cycle. In this case, it was the sudden plunge in progesterone, the hormone that had kept the endometrial wall nourished and in place, which now causes the dramatic menstrual events that mark the first phase of the reproductive cycle. As menstruation begins, none of the key hormones are present in significant quantity.
In the days before you begin to menstruate, the uterine wall, or endometrium, has reached its full maturity, approximately 8–13 millimeters thick. Cellular proliferation in the endometrium has been accompanied by swelling and secretory development, as well as an increased supply of nutrients and blood vessels that have built up over the previous cycle. In brief, the endometrium has reached the goal necessary for its only purpose: to provide the appropriate conditions to nurture a fertilized ovum.
Now, on Day 1, with neither progesterone nor the HCG (human chorionic gonadotropin) that an implanted embryo would supply, the endometrial wall begins to disintegrate. Over a period of approximately 5 days, the uterine lining is gradually washed away as the blood vessels that supply it with nutrients and oxygen begin to constrict. Menstrual blood begins to flow from the uterus through the cervix and out the vagina. The secretion that results also contains matter from the collapsing endometrium. Over the course of your period, you will generally lose anywhere from 1 to 4 ounces of blood and other fluids, though 2.5 ounces appear to be more typical.
As soon as you have begun to menstruate, your body’s endocrine system has started to take action. Even before the first day of the new cycle, the pituitary gland has already begun to secrete small but ever increasing amounts of FSH, the hormone that begins to develop the dozen or so follicles in the ovary that will later compete for the prize of ovulation a couple of weeks later. It’s generally believed that the plunging levels of progesterone and estrogen in the last few days of the previous cycle is what allows for the increased production of FSH. In other words, it was the high levels of progesterone (and to a lesser extent estrogen) that had been blocking FSH production.
By about Day 5, or just as menstruation is ending, the pituitary also begins to release small but increasing amounts of LH. It is believed that LH production within this stage of the cycle is about 3 days behind production of FSH. In fact, the gradual release of LH is a direct result of a positive feedback system triggered by the previous production of FSH. As the FSH begins to act on the handful of ovarian follicles that move toward ovulatory potential, they begin to develop a new coating of granulosa cells, cells that in turn begin to secrete the first amounts of estrogen for the new cycle.
It is this new estrogen that apparently signals the hypothalamus to release GnRH, which in turn triggers the gradually increasing secretion of LH. This newly released LH, working in biochemical unison with FSH, continues to develop those follicles whose growth now extends this positive feedback system of follicular development for the next several days. As your period ends, the hormonal game plan is now well on its way to creating the conditions necessary for ovulation. Indeed, follicular growth during menstruation has already doubled the size of the several primordial follicles that have started to mature for that cycle.
By Day 7 or 8, and for reasons not completely understood, one of the follicles begins to emerge as dominant, while
the others begin to disintegrate in a process called atresia. Many endocrinologists believe that the dominant follicle has begun to secrete so much estrogen in the week or so following menstruation (Days 6 to 12) that LH and FSH production is somewhat decreased. It’s believed that the increased estrogen begins to signal the hypothalamus to reduce production of GnRH, thus slowing the manufacture of LH and FSH. And it is this slowdown that leads to the atresia of most of the other primary follicles, though the dominant follicle continues to mature. (In cases of multiple ovulation, two or more follicles progress to complete maturation.)
While creation of FSH and LH is therefore reduced in Days 6 to 12, estrogen production from the emerging dominant follicle begins to rise dramatically. This rising level of estrogen begins to act on your uterus, in both noticeable and subtle ways. As the estrogen rises, the endometrial cycle also begins anew, with the beginning creation of stromal and epithelial cells within the uterus. By about Day 12, this building process has resulted in an endometrial wall approaching 5–7 millimeters thick, whereas when menstruation had ended a week earlier, there was virtually no such structure in existence.
As this process moves forward, the rising levels of estrogen are also beginning to produce the fertility signs that form the foundation of this book. Usually by about Day 8 or 9, their effect on cervical glands have triggered the first flow of cervical fluid, although this early in the process it is generally a sticky quality. But as estrogen production from the developing follicles within the ovaries rises to its highest levels on Days 10 through 13, the cervical fluid gradually changes to creamy or wet, and then to slippery eggwhite. Typically by Day 13, estrogen levels have reached their peak, with the resulting cervical fluid having reached its most lubricative consistency. By now, the cervix itself is soft, high, and open.
By Day 12 or 13, something dramatic happens in the hormonal feedback system. As already stated, increasing levels of estrogen are believed to be the reason FSH and LH production are kept relatively low in Days 6 to 13. But at a certain point, and for reasons we don’t truly understand, estrogen production reaches a threshold level in which its hormonal effect on the pituitary abruptly reverses. LH secretion by the anterior pituitary gland suddenly surges six to ten times its normal rate, peaking about 12 to 16 hours before ovulation. Within hours of this LH surge, a less dramatic FSH surge follows. In combination, the two cause a negative feedback effect that suddenly shuts down the production of estrogen in the remaining dominant follicle. The follicle has now fully matured, reaching an approximate size of 15–20 millimeters. For this 28-day journey, you have now reached the halfway point, and thus ovulation is imminent.
Taking Charge of Your Fertility Page 40