"Natural" family planning (NFP), fertility awareness methods (FAM), and rhythm method, are all methods that do not use any medications. There are slight differences between these three methods. It should be noted that the rhythm method, which tracks calendar dates and involves guessing when the fertile time occurs, is no longer promoted. Rhythm does not make use of the scientific advances that have occurred in identifying the signs of fertility.

"Natural" family planning (NFP) and fertility awareness methods (FAM) help identify the times during the menstrual cycle when pregnancy is most likely to occur. The fertile times are identified by checking some or all of daily body changes. Some of these are: basal body temperature (your resting temperature), cervical mucus consistency, and position of the cervix in the vagina. Once you have learned to keep track of these signs that can identify when an egg is likely to be released from the ovary (the "fertile" days), you can avoid having sex on the days around that time.

NFP or FAM can be very effective but only if the woman or couple is careful to learn the correct methods to identify and keep track of the menstrual cycle changes. Some couples use birth control methods such as barriers if they have intercourse during the "fertile" days. Other couples prefer to completely abstain from sexual intercourse on the "fertile" days.

Advantages of NFP or FAM are:

• Inexpensive and easily accessible.
• Increased awareness of the body's functioning.
• Can be used to plan and achieve a pregnancy as well as to avoid pregnancy.
• Positive psychological effects may include: couples' development of greater communication, cooperation, and shared responsibility for practicing birth control; these are acceptable methods for women and couples whose personal values conflict with other methods of birth control.

Possible disadvantages and side effects:

• Learning to use NFP or FAM takes time and practice. Classes are sometimes available in the community or from other users.
• Continued use takes commitment, calculation, planning and cooperation between a woman and her partner.
• There is no protection from HIV/AIDS or STDs such as Chlamydia, gonorrhea, syphilis, warts, hepatitis, or human papilloma virus (HPV).
• These methods are less reliable in women with irregular periods or who are breastfeeding.
• Increased abstinence may be required during certain times.
• Negative psychological effects may include a sense of disappointment or guilt if abstinence is not practiced during "fertile" times as intended.

Possible health risks:

• There are no health risks to successful use of these methods.

It is important to understand what happens to the body during puberty and a woman’s menstrual cycle, how a woman’s reproductive system works, and how overall health and wellness are connected to fertility and the reproductive system.

Understanding the body and the biology of reproduction can inform decisions about preventing pregnancy and deciding whether and when to become pregnant. The next sections describe the basics of puberty, the menstrual cycle, what it means to have fertility awareness and use fertility awareness-based methods (FABM) of family planning, and infertility in women and men.

Puberty

Puberty is the time in life when a child reaches sexual maturity. This means that the hormone levels in the body—estrogen and progesterone in girls and testosterone in boys—increase and cause physical and emotional changes to occur. Puberty usually happens between ages 8 and 13 for girls and ages 10 and 15 for boys, and the process affects boys and girls differently. When girls reach puberty, they typically start their menstrual cycle.

Menstrual Cycle

The menstrual cycle refers to the monthly process that happens in a woman’s body to prepare for a possible pregnancy. It includes the release of an egg from the ovaries (called ovulation), changes in the cervix and thickening of the uterine wall, several hormonal changes, and shedding of the thickened uterine wall through bleeding (called menstruation, also known as a “period” or “menses”). Hormonal fluctuations drive the changes that occur during the menstrual cycle. If pregnancy does not occur, the body sheds the extra lining of the uterus. The blood and tissue leave the uterus through the cervix and exit the body through the vagina. The length of the menstrual cycle is the number of days starting from the first day when bleeding begins until the first day of the next month when bleeding begins again.

Regular menstrual periods occurring in the years between puberty and menopause are usually a sign that the female body is working normally. Some women experience problems with menstruation, such as irregular or heavy, painful periods; this may be a sign of a health problem. Many women also experience premenstrual syndrome (PMS) symptoms. Women with period problems or PMS should talk to a health care provider about ways to treat these issues.

In addition to the hormonal changes and the changes happening inside the body, females may also notice changes in their vaginal discharge. Vaginal discharge is a fluid—usually white or clear—that comes out of the vagina. Most females have vaginal discharge. The amount and consistency of vaginal discharge changes at different points in a female’s cycle. Increased vaginal discharge can be caused by normal menstrual cycle changes, vaginal infection, or cancer (rare). Unusual vaginal discharge can also be a symptom of pelvic inflammatory disease (PID), an infection of a female’s reproductive organs often caused by some sexually transmitted infections (STIs). If a female has more than her usual amount of vaginal discharge, she may need to see her health care provider.

How to Chart Menstrual Cycles

To chart her menstrual cycle, a woman can simply record the day her period starts and when it ends on a paper or electronic calendar. Smartphone and computer applications that chart menstrual cycles are also available. Over time, this tracking will help a woman see what the typical amount of time between periods is, which can help her predict when her next period will start.

Tracking the menstrual cycle can provide useful information for conversations with health care providers. For example, a patient may want to discuss the length of her cycle or her experiences with pain or extreme bleeding during her cycle. In addition, tracking the cycle is key to predicting ovulation, which can inform decisions about when to have sex, whether the intent is to avoid pregnancy or become pregnant.

Fertility Awareness

Fertility awareness means being aware of the menstrual cycle and the changes in a woman’s body that happen during this time and understanding when a woman is most likely to get pregnant. Women and couples become more familiar with the signs of ovulation and the pattern of the menstrual cycle to understand how to plan sexual activity to avoid pregnancy or become pregnant.

Fertility Awareness-Based Methods (FABM) of Family Planning

Fertility awareness-based methods (FABM) involve a woman learning to recognize the signs of her fertile days, which are the days of each month in which she is most likely to become pregnant (conceive). Based on her intentions, she may plan to have unprotected sex during this time in order to conceive, or she may choose to avoid pregnancy by not having sex or by using a barrier birth control method, like condoms, during this time.

There are multiple fertility awareness-based methods that women can use, such as the following:

• Natural family planning
• Standard days or calendar method
• Cervical mucous method
• Basal body temperature method
• Ovulation method
• Symptothermal method (combining the other methods)

Infertility

Infertility is defined as not being able to become pregnant after having regular intercourse (sex) without birth control after one year (or after six months if a woman is 35 or older). Infertility is common. Out of 100 couples in the United States, about 12 to 13 of them have trouble becoming pregnant.

About one-third of infertility cases are caused by fertility problems in women and another one-third of infertility cases are due to fertility problems in men. The other cases are caused by a mixture of male and female problems or by problems that cannot be determined.

Infertility in Women

Most cases of female infertility are caused by problems with ovulation. Ovulation problems can be caused by hormone imbalances from a variety of causes. Although less common, blocked fallopian tubes can also cause female infertility. If the fallopian tube is blocked due to infection, surgery, or other problems, then sperm cannot reach the egg to fertilize it.

Other less common causes of fertility problems in women can include physical problems with the uterus or uterine fibroids, which are non-cancerous tumors made of fibrous tissue and muscle cells that develop on the walls of the uterus.

Infertility in Men

There are a few different causes for male infertility. Erectile dysfunction is when a man cannot get or keep an erection (get hard) for sex. Without an erection, it is difficult for a man to release sperm inside the vagina – and, therefore, difficult to get a woman pregnant.

Another problem is varicocele, which is when the veins in a man’s scrotum (sac) can become too large. These big veins heat and cool the testes. When the big veins heat the testes too much, the heat damages the sperm. Sperm damage can cause male infertility.

If a man makes too few sperm or none at all, the woman cannot become pregnant. Also, if a man’s sperm do not move correctly, they may not be able to meet with and fertilize an egg. Additionally, if the tubes through which sperm travel are blocked, the sperm cannot travel into and out of the penis to meet with and fertilize an egg.

Ovulation, prompted by luteinizing hormone from the anterior pituitary, occurs when the mature follicle at the surface of the ovary ruptures and releases the secondary oocyte into the peritoneal cavity. The ovulated secondary oocyte, ready for fertilization is still surrounded by the zona pellucida and a few layers of cells called the corona radiata. If it is not fertilized, the secondary oocyte degenerates in a couple of days. If a sperm passes through the corona radiata and zona pellucida and enters the cytoplasm of the secondary oocyte, the second meiotic division resumes to form a polar body and a mature ovum

After ovulation and in response to luteinizing hormone, the portion of the follicle that remains in the ovary enlarges and is transformed into a corpus luteum. The corpus luteum is a glandular structure that secretes progesterone and some estrogen. Its fate depends on whether fertilization occurs. If fertilization does not take place, the corpus luteum remains functional for about 10 days; then it begins to degenerate into a corpus albicans, which is primarily scar tissue, and its hormone output ceases. If fertilization occurs, the corpus luteum persists and continues its hormone functions until the placenta develops sufficiently to secrete the necessary hormones. Again, the corpus luteum ultimately degenerates into corpus albicans, but it remains functional for a longer period of time.

Knowing when you're most fertile will help you plan pregnancy. There are three ways you can keep track of your fertile times. They are:

• Basal body temperature method – Basal body temperature is your temperature at rest as soon as you awake in the morning. A woman's basal body temperature rises slightly with ovulation. So by recording this temperature daily for several months, you'll be able to predict your most fertile days.

  Basal body temperature differs slightly from woman to woman. Anywhere from 96 to 98 degrees Fahrenheit orally is average before ovulation. After ovulation most women have an oral temperature between 97 and 99 degrees Fahrenheit. The rise in temperature can be a sudden jump or a gradual climb over a few days.

  Usually a woman's basal body temperature rises by only 0.4 to 0.8 degrees Fahrenheit. To detect this tiny change, women must use a basal body thermometer. These thermometers are very sensitive. Most pharmacies sell them for about $10.

  The rise in temperature doesn't show exactly when the egg is released. But almost all women have ovulated within three days after their temperatures spike. Body temperature stays at the higher level until your period starts.

  You are most fertile and most likely to get pregnant:

  • Two to three days before your temperature hits the highest point (ovulation)
    and
  • 12 to 24 hours after ovulation

  A man's sperm can live for up to three days in a woman's body. The sperm can fertilize an egg at any point during that time. So if you have unprotected sex a few days before ovulation, you could get pregnant.

  Many things can affect basal body temperature. For your chart to be useful, make sure to take your temperature every morning at about the same time. Things that can alter your temperature include:

  • Drinking alcohol the night before
  • Smoking cigarettes the night before
  • Getting a poor night's sleep
  • Having a fever
  • Doing anything in the morning before you take your temperature — including going to the bathroom and talking on the phone
    

• Calendar method – This involves recording your menstrual cycle on a calendar for eight to 12 months. The first day of your period is Day 1. Circle Day 1 on the calendar. The length of your cycle may vary from month to month. So write down the total number of days it lasts each time. Using this record, you can find the days you are most fertile in the months ahead:

  1. To find out the first day when you are most fertile, subtract 18 from the total number of days in your shortest cycle. Take this new number and count ahead that many days from the first day of your next period. Draw an X through this date on your calendar. The X marks the first day you're likely to be fertile.
  2. To find out the last day when you are most fertile, subtract 11 from the total number of days in your longest cycle. Take this new number and count ahead that many days from the first day of your next period. Draw an X through this date on your calendar. The time between the two Xs is your most fertile window.

  This method always should be used along with other fertility awareness methods, especially if your cycles are not always the same length.

• Cervical mucus method (also known as the ovulation method) – This involves being aware of the changes in your cervical mucus throughout the month. The hormones that control the menstrual cycle also change the kind and amount of mucus you have before and during ovulation. Right after your period, there are usually a few days when there is no mucus present or "dry days." As the egg starts to mature, mucus increases in the vagina, appears at the vaginal opening, and is white or yellow and cloudy and sticky. The greatest amount of mucus appears just before ovulation. During these "wet days" it becomes clear and slippery, like raw egg whites. Sometimes it can be stretched apart. This is when you are most fertile. About four days after the wet days begin the mucus changes again. There will be much less and it becomes sticky and cloudy. You might have a few more dry days before your period returns. Describe changes in your mucus on a calendar. Label the days, "Sticky," "Dry," or "Wet." You are most fertile at the first sign of wetness after your period or a day or two before wetness begins.

  The cervical mucus method is less reliable for some women. Women who are breastfeeding, taking hormonal birth control (like the pill), using feminine hygiene products, have vaginitis or sexually transmitted infections (STIs), or have had surgery on the cervix should not rely on this method.

To most accurately track your fertility, use a combination of all three methods. This is called the symptothermal method. You can also purchase over-the-counter ovulation kits or fertility monitors to help find the best time to conceive. These kits work by detecting surges in a specific hormone called luteinizing hormone, which triggers ovulation.

Female fertility (the ability to conceive) peaks when women are in their twenties, and is slowly reduced until a women reaches 35 years of age. After that time, fertility declines more rapidly, until it ends completely at the end of menopause. Menopause is the cessation of the menstrual cycle that occurs as a result of the loss of ovarian follicles and the hormones that they produce. A woman is considered to have completed menopause if she has not menstruated in a full year. After that point, she is considered postmenopausal. The average age for this change is consistent worldwide at between 50 and 52 years of age, but it can normally occur in a woman’s forties, or later in her fifties. Poor health, including smoking, can lead to earlier loss of fertility and earlier menopause.

As a woman reaches the age of menopause, depletion of the number of viable follicles in the ovaries due to atresia affects the hormonal regulation of the menstrual cycle. During the years leading up to menopause, there is a decrease in the levels of the hormone inhibin, which normally participates in a negative feedback loop to the pituitary to control the production of FSH. The menopausal decrease in inhibin leads to an increase in FSH. The presence of FSH stimulates more follicles to grow and secrete estrogen. Because small, secondary follicles also respond to increases in FSH levels, larger numbers of follicles are stimulated to grow; however, most undergo atresia and die. Eventually, this process leads to the depletion of all follicles in the ovaries, and the production of estrogen falls off dramatically. It is primarily the lack of estrogens that leads to the symptoms of menopause.

The earliest changes occur during the menopausal transition, often referred to as peri-menopause, when a women’s cycle becomes irregular but does not stop entirely. Although the levels of estrogen are still nearly the same as before the transition, the level of progesterone produced by the corpus luteum is reduced. This decline in progesterone can lead to abnormal growth, or hyperplasia, of the endometrium. This condition is a concern because it increases the risk of developing endometrial cancer. Two harmless conditions that can develop during the transition are uterine fibroids, which are benign masses of cells, and irregular bleeding. As estrogen levels change, other symptoms that occur are hot flashes and night sweats, trouble sleeping, vaginal dryness, mood swings, difficulty focusing, and thinning of hair on the head along with the growth of more hair on the face. Depending on the individual, these symptoms can be entirely absent, moderate, or severe.

After menopause, lower amounts of estrogens can lead to other changes. Cardiovascular disease becomes as prevalent in women as in men, possibly because estrogens reduce the amount of cholesterol in the blood vessels. When estrogen is lacking, many women find that they suddenly have problems with high cholesterol and the cardiovascular issues that accompany it. Osteoporosis is another problem because bone density decreases rapidly in the first years after menopause. The reduction in bone density leads to a higher incidence of fractures.

Hormone therapy (HT), which employs medication (synthetic estrogens and progestins) to increase estrogen and progestin levels, can alleviate some of the symptoms of menopause. In 2002, the Women’s Health Initiative began a study to observe women for the long-term outcomes of hormone replacement therapy over 8.5 years. However, the study was prematurely terminated after 5.2 years because of evidence of a higher than normal risk of breast cancer in patients taking estrogen-only HT. The potential positive effects on cardiovascular disease were also not realized in the estrogen-only patients. The results of other hormone replacement studies over the last 50 years, including a 2012 study that followed over 1,000 menopausal women for 10 years, have shown cardiovascular benefits from estrogen and no increased risk for cancer. Some researchers believe that the age group tested in the 2002 trial may have been too old to benefit from the therapy, thus skewing the results. In the meantime, intense debate and study of the benefits and risks of replacement therapy is ongoing. Current guidelines approve HT for the reduction of hot flashes or flushes, but this treatment is generally only considered when women first start showing signs of menopausal changes, is used in the lowest dose possible for the shortest time possible (5 years or less), and it is suggested that women on HT have regular pelvic and breast exams.