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↑ Note that
All participants in the study, even those considered "typical-use", took part in Arbeitsgruppe NFP's teaching sessions prior to application of the method (see study section "Teaching the STM")
The primary author of the study, P. Frank-Herrmann, is a member of Forschungsgruppe NFP which cooperates with the Malteser Arbeitsgruppe NFP เก็บถาวร 2017-12-10 ที่ เวย์แบ็กแมชชีน. She also actively recommends the Sensiplan brand on her homepage เก็บถาวร 2017-12-10 ที่ เวย์แบ็กแมชชีน. Sensiplan teachers licensed by Malteser Arbeitsgruppe NFP sell teaching session packages for 120 EUR; the group also sells teacher certificates for 500-800 EUR and licenses the Sensiplan brand to vendors of an app (myNFP) and monitoring device (OvulaRing), as well as to teachers of the method.
The study considered only the teaching. The sensiplan app and measurement device where not tested, neither alone, nor in combination with the teaching
Malteser gGmbh is a tax-exempt, but for-profit company, owned by a catholic association. Arbeitsgruppe NFP is controlled by the Episcopal Conference of Germany เก็บถาวร 2017-12-11 ที่ เวย์แบ็กแมชชีน The catholic church has moral teachings that consider any method other than NFP as immoral.
The study notes anomalies in the results. Additional condom use made no difference: "The authors were surprised"; observed pregnancy rate for couples that had unprotected sex during the fertile period was 7.5% (instead of the typical 85%): "surprisingly low"; no difference for the teaching phase: "as low as in the subsequent cycles". The authors offer only speculative explanations for these anomalies.
The study stresses that it was not a randomized controlled trial.
The study excluded persons younger than 19 years.
Of 900 women who were admitted to the study, 671 dropped out before the end. The most frequently named reason was a wish to discontinue participating in the study despite being satisfied with the method.
The homepage of Sensiplan licensee OvulaRing has a disclaimer statement saying that typical-use failure rate of the symptothermal method is considered to be up to 20% เก็บถาวร 2017-12-10 ที่ เวย์แบ็กแมชชีน
↑  The pregnancy rate applies until the user reaches six months postpartum, or until menstruation resumes, whichever comes first. If menstruation occurs earlier than six months postpartum, the method is no longer effective. For users for whom menstruation does not occur within the six months: after six months postpartum, the method becomes less effective.
1 2  In the effectiveness study of Lea's Shield, 84% of participants were parous.  The unadjusted pregnancy rate in the six-month study was 8.7% among spermicide users and 12.9% among non-spermicide users.  No pregnancies occurred among nulliparous users of the Lea's Shield.  Assuming the effectiveness ratio of nulliparous to parous users is the same for the Lea's Shield as for the Prentif cervical cap and the Today contraceptive sponge, the unadjusted six-month pregnancy rate would be 2.2% for spermicide users and 2.9% for those who used the device without spermicide.
1 2 3  Nulliparous refers to those who have not given birth.
1 2 3  Parous refers to those who have given birth.
↑  No formal studies meet the standards of Contraceptive Technology for determining typical effectiveness. The typical effectiveness listed here is from the CDC's National Survey of Family Growth, which grouped symptoms-based methods together with calendar-based methods. See Fertility awareness#Effectiveness.
↑  The term fertility awareness is sometimes used interchangeably with the term natural family planning (NFP), though NFP usually refers to use of periodic abstinence in accordance with Catholic beliefs.
↑  Users may observe one of the three primary fertility signs.  Basal body temperature (BBT) and cervical position are checked once per day.  Cervical mucus is checked before each urination, and vaginal sensation is observed throughout the day.  The observed sign or signs are recorded once per day.
↑  Strictly speaking, abstinence pledges are not a method of birth control, as their purpose is preservation of the virginity of unmarried girls, with prevention of pregnancies only being a side-effect. This also means that they are restricted to the time before marriage.
↑  Several factors may contribute to the fact that the placebo was observed to be significantly less effective than unprotected intercourse: 1. The study was not representative, as it only considered women of low socioeconomic level who had aborted spontaneously and desired pregnancy, 2. the placebo may have caused behavioral differences compared to unprotected intercourse: the couples might assume to be protected and thus be less relucatant to have sex and/or be in a different psychological mood that increases fertility via psychosomatic action