Superiority of NFP in Population Control


Statistically, has Natural Family Planning been proven to be more effective in population control than Artificial Family Planning? I heard an archive program days ago where Deacon Burke-Sivers cited the comparative study done by some British agency between the percentage failure rate of NFP and AFP in India. He said the NFP failure was 0.001% while AFP was 1%. Is this true? Where can I find a website that has comparative studies like these?

Thank you already.

Peace, so be it.


I don’t know that there is any study that says NFP is better at “population control”. NFP is successful in planning families and as successful (perhaps) better than other means.

In the case of India or third world countries, think about it. If the idea is to promote hormonal contraceptives, who pays for all those pills? How do they get shipped and available everywhere? Can many of these poor women remember to take them on time? Do they have regular access to doctors to evaluate the problems that occur with pills? All of this, IMHO, can hamper the success rate of hormonal contraceptives.

The nice thing with NFP is that each women takes control of their fertility with her husband. No need for doctors, pharmacies, etc. Only the chance to learn the method. Then they can benefit from stable families, better understanding of their health, etc.


I hope we are not advocating population control!

I am assuming we are looking for evidence of higher efficacy of NFP.


***N***atural Family Planning

Q.1. How effective are Natural Family Planning
(NFP) methods?

Estimates of NFP effectiveness vary widely. NFP effectiveness depends upon several factors, including:

]The fertility indicator(s) used,
]The validity of the rules used,
]The type and quality of teaching,
]The ability of the woman to observe and interpret her fertility signs,
]The ability of the couple to abstain from vaginal intercourse when indicated by the rules, and
]Individual characteristics of the couple, such as the age of the woman and her history of pelvic infection or other determinants of lowered fertility.
[/list]**Calendar-based methods
Estimates from clearly reported trials that state the rule used range from 5% to 14% in the first year of use. A recent reanalysis of calendar method clinical studies found a typical failure rate estimate of about 20%.

Rationale: It is difficult to estimate the effective- ness of the calendar method because very few well-designed studies have been conducted. Many of the estimates are based upon surveys and do not report the requisite information required to calculate effectiveness rates. It is difficult to compare studies on the calendar method because many reports do not state what rule was used to identify the fertile time or if couples understood the basis for the method (65, 165).

**Single-indicator methods
(basal body temperature (BBT),
cervical mucus or ovulation methods)**Estimate: Estimates range from 3% with perfect use to about 20% with typical use.

Rationale: The probability of accidental pregnancy when using single indicator methods is highest when couples do not abstain during the fertile period. For users of the cervical mucus or ovulation methods, having intercourse during periods of stress on the woman also increases the risk of pregnancy by affecting the quality of mucus. For users of the BBT method, stress, illness, travel, or interrupted sleep can disrupt a woman’s typical biphasic pattern, thereby making it difficult to identify the fertile period for that cycle using the body temperature (114, 275, 356).

**Two or more indicator methods
(symptothermal methods)**Estimate: Estimates range from about 2% with perfect use to about 15% to 20% with typical use.

Rationale: The use of two or more indicators can be somewhat more effective than the use of a single indicator (90, 114).
from here.
Data from 1996.


Tlaloc, quoting the article: The probability of accidental pregnancy when using single indicator methods is highest when couples do not abstain during the fertile period.

ke: Anyone who does not abstain during the fertile period is NOT using the method. They have ABANDONED the method. They are engaging in achieving behavior, not avoiding behavior. The idea that one engages in sexual intercourse during a known fertile day and then has an “accidental” pregnancy is absurd. One knows they are fertile, therefore one is knowingly engaging in a fertile act. This is not method failure.

Yes, there is usage failures such as not interpreting signs correctly, getting lazy with charting, etc. Method effectiveness for NFP is quite high, over 99%. Usage failure takes into account human error, just as usage failure for ABC takes into account both human error and manufacturer’s defect.


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