NFP Overview

NFP & Contraception: A Comparison

    Natural Family Plannning…


  • is 99% effective at achieving or avoiding pregnancy.
  • is 100% natural, without use of chemicals, injections, or patches.
  • is 100% safe and risk-free from disease and illness.
  • is environmentally-friendly.
  • promotes the human body’s natural function.
  • reveals underlying health issues concerning fertility.
  • provides reliable information about one’s fertility.




  • is only 72-99% effective at avoiding pregnancy, varying according to method. In 2002, 12% of all episodes of contraceptive-use failed.
  • is not natural, requiring chemicals, injections, devices, procedures, or patches.
  • is not safe. Studies indicate links between contraceptive-use and both cervical and breast cancers.
  • damages the environment, creating wastes from used condoms and introducing chemicals into the water supply and ecosystem.
  • represses the human body’s natural function.
  • masks underlying health issues concerning fertility.
  • inhibits access to reliable information about one’s fertility.


How NFP Works

To better understand how natural family planning works, it is helpful to review basic reproductive anatomy.

The male reproductive cell is the sperm and the female reproductive cell is the egg or ovum. A new human life begins at conception, when a sperm and an egg unite. Conception occurs within the woman’s fallopian tube and the new baby immediately begins growing and developing.

But first, in order for pregnancy to occur, a number of conditions must be present. These conditions are healthy sperm, healthy eggs and the presence of cervical mucus.

  • Healthy SpermSperm are produced in the testicles; and during intercourse, millions of sperm cells are released in the vagina. A healthy male produces sperm continuously throughout his life.
  • Healthy EggWomen, on the other hand, are born with hundreds of thousands of eggs. During a woman’s menstrual cycle, one or more of these eggs will develop within the ovary. Ovulation is when a fully developed egg ruptures from the follicle and is released from the ovary. Usually only one egg is released during a woman’s cycle. The mature egg, once released, will only live for approximately 12 – 24 hours.
  • Cervical MucusSperm need cervical mucus to survive. Sperm, in the absence of good mucus, will die literally within hours or even minutes when placed into the vagina. The vagina which is mostly acidic, is actually a poor environment for sperm. However, at certain times in a woman’s monthly cycle, she produces a fluid called cervical mucus, that actually changes the chemical nature of the vagina and allows the sperm to survive longer. When cervical mucus is present, sperm can survive from 3 to 5 days.

Thus, for a woman to become pregnant, three factors are critical: healthy sperm, healthy egg, and cervical mucus.

Monitoring Fertility and Infertility

There are three phases of a woman’s menstrual cycle:

  • Pre-Ovulation

    This phase of a woman’s cycle begins on the first day of her bleeding, and ends on the day of ovulation. In the pre-ovulation phase, a chemical messenger from the brain signals an egg to develop. The follicle, which is where the egg develops, produces the reproductive hormone, estrogen. Estrogen helps prepare the inside of the vagina for sperm, and the uterus for pregnancy. Since hormone levels vary, the length of the woman’s pre-ovulation phase can change from cycle to cycle. Research indicates that many factors can affect the length of the woman’s cycle, including: breastfeeding, weight loss, stress, illness, and diet. Despite this, the time of fertility can be known with clarity because of the signs the woman’s body produces that help her identify when the window of fertility begins and when it ends.

  • Ovulation

    This is the optimal time of fertility. A woman has hundreds of thousands of eggs contained in two symmetric organs, called ovaries. Ovulation occurs when a hormone signals the ovary to release a mature egg. During ovulation, the cervix (located at the base of the uterus) rises in the pelvic cavity, opening and softens. The cervix also produces cervical mucus, which neutralizes the acidic nature of the vagina, allowing sperm to survive and move through the uterus into the fallopian tubes. Finally, during ovulation, the interior of the uterus changes to sustain a pregnancy by building a nutrient-rich lining (“endometrium”).

  • Post-Ovulation

    The third phase of a woman’s cycle begins after ovulation and ends the day before her next period. It is very stable in length and ranges between 9 to 16 days. After ovulation, the hormone progesterone increases in the woman’s body. Progesterone has three critical functions: (1) stimulates cervical cells to produce a thick mucus so that the sperm can not penetrate the cervix. If fertilization did not occur earlier in the cycle, progesterone levels decrease and the uterus lining sheds. (2) Most importantly, progesterone prepares the lining of the uterus for possible implantation of a new human life. The uterus will keep the new life safe and nourished for the next 9 months; (3) During ovulation, Progesterone elevates the woman’s body temperature about four to six tenths (4/10 – 6/10) of one degree (F). This increase can be detected by taking daily waking temperatures, called Basal Body Temperature (BBT). This daily temperature reading is one of the key signs a couple can use to monitor where the woman is at in her fertility cycle. (The other key sign is the presence of cervical mucus.)

Natural Family Planning is as simple as learning the basics of the woman’s ovulation cycle and tracking her fertility on any given day. By careful monitoring the signs of ovulation (i.e. Basal Body Temperature and Cervical Mucus), and tracking any changes, a couple can know with confidence if the woman is in the ovulation phase or not. As such, they can plan accordingly to achieve, avoid, postpone pregnancy, depending upon their intentions.

Note: This provides only a preliminary overview of how fertility can be monitored. To learn more, register for an NFP class.

NFP Methods

The Archdiocese of New York offers several different NFP courses every month. You can choose from the following methods:

Thermal-reading Methods

Thermal-reading NFP methods inform couples of fertility through charting “multiple signs & symptoms”: cervical mucus, Basal Body Temperature (BBT), and palpation of the cervix.

  • Archdiocesan Sympto-ThermalThis effective, “one rule” method is taught through a simple and straightforward curriculum in a classroom setting.
  • Couple to Couple League’s Sympto-Thermal Method (STM)The Couple to Couple League (CCL) uses a Sympto-Thermal Method (STM) based on daily fertility awareness. A couple charts the woman’s signs of fertility day-by-day and uses that information to determine her fertile and infertile times. It can be used both to achieve, avoid, or postpone pregnancy. CCL’s curriculum incorporates the teachings of Bl. Pope John Paul II’s Theology of the Body, helping couples recognize true marital love and responsible parenthood. Classes are taught by couples using this method and trained professionally by the Couple to Couple League.

Key features of Thermal-reading methods: Sympto-thermal Methods add a level of crosschecking that some couples find helpful. Archdiocesan method is a more “simplified” and the CCL is a more “quantified” method.

Mucus-based (Ovulatory) Methods

Mucus-based (Ovulatory) NFP methods inform couples of fertility through the observation and charting of “signs & symptoms” of fertility & infertility observable at the vulva, particularly mucus secretions.

  • Billings Ovulation MethodThe Billings Ovulation Method does not use any form of rhythm counting, temperature taking, etc. Instead, there are four simple rules that are applied, whether the couple wishes to achieve or avoid pregnancy. As such, Billings is one of the most simplified NFP methods. The Billings method is used in more than 120 countries, with 3.6 million couples in China, and is popular in the US as well as in many under-developed countries. Also offered in Spanish.
  • Creighton Method FertilityCareTMThe Creighton Model FertilityCare SystemTM, affiliated with the Pope Paul VI Institute’s National Center for Women’s Health, teaches women to observe certain biological signs to identify times of fertility & infertility. These signs (including cervical mucus and bleeding patterns) are charted daily to give an overall picture of a woman’s individual cycle. The Creighton Model FertilityCareTM System (CrMS) is a modification of the Billings Ovulation Method. The versatility of CrMS is one of its strongest features. Like Billings, it too monitors mucus at the vulva. The events leading up to ovulation are “quantified ” in a more detailed manner, thus recognizing times of fertility & infertility in a definitive, “day-by-day” fashion. As such, previously difficult cases, such as long and irregular cycles, breastfeeding, coming off of contraceptive pills, and ovulatory states in the pre-menopause, all can now be brought into focus readily through this data.

Key Features of the Mucus-based Methods: The Billings & Creighton Methods involve the monitoring of mucus. A large appeal of Billings could be summarized as “simplicity.” Billings is more simplified than Creighton, requiring just daily charting and “four simple rules” related to fertility. Creighton appeals to many by offering couple more data on a daily basis. Over a number of cycles, this additional data can be instrumental in dealing with various issues (mentioned above). Also, there are “Creighton practitioners” (including MD’s) who can provide medical support for the couple within this method.

Creighton may also be used in conjunction with NaProTechnology. NaProTechnology effectively monitors and maintains gynecological health, including infertility and miscarriage issues. NaProTechnology is a fertility-care medical approach that cooperates with a woman’s natural hormonal cycle to treat the underlying cause of fertility-related problems.

Family Life † Respect Life