Natural conception rates in subfertile couples following fertility awareness training

Abstract

Purpose:
To analyze cumulative pregnancy rates of subfertile couples after fertility awareness training.

Methods:
A prospective observational cohort study followed 187 subfertile women, who had received training in self-observation of the fertile phase of the menstrual cycle with the Sensiplan method, for 8 months. The women, aged 21-47 years, had attempted to become pregnant for 3.5 years on average (range 1-8 years) before study entry. Amenorrhea, known tubal occlusion and severe male factor had been excluded. An additional seven women, who had initially been recruited, became pregnant during the cycle immediately prior to Sensiplan training: this is taken to be the spontaneous pregnancy rate per cycle in the cohort in the absence of fertility awareness training.

Results:
The cumulative pregnancy rate of subfertile couples after fertility awareness training was 38% (95% CI 27-49%; 58 pregnancies) after eight observation months, which is significantly higher than the estimated basic pregnancy rate of 21.6% in untrained couples in the same cohort. For couples who had been seeking to become pregnant for 1-2 years, the pregnancy rate increased to 56% after 8 months. A female age above 35 (cumulative pregnancy rate 25%, p = 0.06), couples who had attempted to become pregnant for more than 2 years (cumulative pregnancy rate 17%, p < 0.01), all significantly reduce the chances of conceiving naturally at some point.

Conclusions:
Training women to identify their fertile window in the menstrual cycle seems to be a reasonable first-line therapy in the management of subfertility.

Full text

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Arch Gynecol Obstet (2017) 295:1015–1024
DOI 10.1007/s00404-017-4294-z
GYNECOLOGIC ENDOCRINOLOGY AND REPRODUCTIVE MEDICINE
Natural conception rates insubfertile couples followingfertility
awareness training
P.Frank‑Herrmann1 · C.Jacobs1· E.Jenetzky2· C.Gnoth3· C.Pyper4· S.Baur3·
G.Freundl3· M.Goeckenjan5· T.Strowitzki1
Received: 17 October 2016 / Accepted: 10 January 2017 / Published online: 9 February 2017
© Springer-Verlag Berlin Heidelberg 2017
27–49%; 58 pregnancies) after eight observation months,
which is significantly higher than the estimated basic
pregnancy rate of 21.6% in untrained couples in the same
cohort. For couples who had been seeking to become preg-
nant for 1–2 years, the pregnancy rate increased to 56%
after 8 months. A female age above 35 (cumulative preg-
nancy rate 25%, p = 0.06), couples who had attempted
to become pregnant for more than 2 years (cumulative
pregnancy rate 17%, p < 0.01), all significantly reduce the
chances of conceiving naturally at some point.
Conclusions Training women to identify their fertile win-
dow in the menstrual cycle seems to be a reasonable first-
line therapy in the management of subfertility.
Keywords Subfertility· Pregnancy rate· Natural family
planning· Fertility awareness method· Sensiplan
Introduction
Background
Sexual intercourse has to take place within the fer-
tile window of the woman’s cycle to make the most of
a particular couple’s natural conception potential. For
most women, even those with relatively regular men-
strual cycles, the time of ovulation and the fertile window
vary markedly. More than half of the women in a nor-
mal population have a variation in cycle length and fertile
window of at least 1 week observed over 1 year [1–4].
This is no problem if couples have intercourse every 1–2
days throughout the whole cycle, as recommended by
the ASRM in 2008 [5]. However, this frequency is not
reached in reality especially over longer periods of time
[6, 7]. This means that couples may be inaccurate in
Abstract
Purpose To analyze cumulative pregnancy rates of sub-
fertile couples after fertility awareness training.
Methods A prospective observational cohort study fol-
lowed 187 subfertile women, who had received training in
self-observation of the fertile phase of the menstrual cycle
with the Sensiplan method, for 8 months. The women,
aged 21–47 years, had attempted to become pregnant for
3.5 years on average (range 1–8 years) before study entry.
Amenorrhea, known tubal occlusion and severe male factor
had been excluded. An additional seven women, who had
initially been recruited, became pregnant during the cycle
immediately prior to Sensiplan training: this is taken to be
the spontaneous pregnancy rate per cycle in the cohort in
the absence of fertility awareness training.
Results The cumulative pregnancy rate of subfertile cou-
ples after fertility awareness training was 38% (95% CI
* P. Frank-Herrmann
petra.frank-herrmann@med.uni-heidelberg.de
1 Department ofGynecological Endocrinology andFertility
Disorders, University ofHeidelberg, Im Neuenheimer Feld
440, 69120Heidelberg, Germany
2 Department forChild andAdolescent Psychiatry
andPsychotherapy, University Medical Center,
Langenbeckstr. 1, 55131Mainz, Germany
3 Section Natural Fertility, German Society ofGynecological
Endocrinology andFertility Medicine, University
ofHeidelberg, Im Neuenheimer Feld 440, 69120Heidelberg,
Germany
4 National Perinatal Epidemiology Unit, Nuffield Department
ofPublic Health, University ofOxford, Old Rd,
OxfordOX37LF, UK
5 Department ofGynecology andObstetrics, University
ofDresden, Fetscherstraße 74, 01307Dresden, Germany

1016 Arch Gynecol Obstet (2017) 295:1015–1024
1 3
timing sexual intercourse to occur during the woman’s
fertile time. Many couples trying for pregnancy believe
that they are most fertile around day 14 and target fre-
quent intercourse between days 10 to 16; they are then
likely to have a reduced frequency of sexual intercourse
from day 17 onwards [1]. But in a 33-day cycle, peak fer-
tility may occur at around day 20. Therefore, inaccurate
timing of sexual intercourse may be a reason for delay in
conception or ongoing subfertility, indicating the need for
accurate fertility awareness education.
The natural family planning (NFP) method called Sen-
siplan is a fertility awareness method (FAM) that enables
a woman to accurately identify her fertile time [8]. Women
observe and interpret cycle symptoms, mainly cervical
secretion changes and basal body temperature, which have
been proven to be reliable indicators of the fertile window
[1, 9–13]. The Sensiplan method’s guidelines are evidence
based and have been developed following extensive fertility
research carried out over the last 25 years [13]. They have
been adopted and disseminated by several European NFP
groups [1, 8, 14]. This paper describes a study cohort of
subfertile couples who were trained to identify the fertile
phase of the menstrual cycle using the Sensiplan method.
Correlation studies have shown that estimates of peak
fertility and ovulation based on cervical secretions and
basal body temperature rise have a high probability of
being within 1–2days of true ovulation (detected by ultra-
sound and LH peak) [2, 9, 10, 15, 16]. Several probability-
of-conception studies have identified the fertile phase as
beginning 5 days prior to ovulation, and extending to the
day of ovulation [17–20]. Furthermore, these studies found
that timing intercourse to occur on days with good cervical
secretion quality was more important for achieving preg-
nancy than planning sexual intercourse to coincide with the
time of likely ovulation [17, 21].
There is some evidence that fertility awareness education
shortens the time-to-pregnancy (TTP): a prospective cohort
TTP study followed up 340 healthy German women using
the Sensiplan method from their first cycle trying for preg-
nancy. The pregnancy rates at 1, 3, 6 and 12 cycles were
38, 68, 81 and 92%, respectively [22]. In their guidelines
on “Optimizing natural fertility” the American Society for
Reproductive Medicine (ASRM) cites this German study in
relation to the good results on the spontaneous achievement
of pregnancy following unprotected intercourse [5, 23].
However, it was not explicitly mentioned that those rates
were achieved by women who had been trained in fertility
awareness methods, i.e., who knew how to identify their
fertile window precisely.
Around 9% of couples fail to conceive within 12 months
of trying [24, 25]. Increasingly these couples are being
referred to assisted reproductive technology (ART) clinics
for subfertility treatment. There is a paucity of data related
to pregnancy rates in subfertile women who use fertility
awareness methods (FAM) [26–28].
Objectives
The primary aim of this study was to determine the cumu-
lative spontaneous conception rate after subfertile couples
were trained to identify their fertile window.
A secondary aim of the study was to explore whether
the planning and implementation of diagnostic tests for
subfertility can be performed more efficiently if the fertile
window is identified; the results of this investigation will be
presented in another paper.
Materials andmethods
The study was conducted between 2004 and 2008 by the
Department of Gynecological Endocrinology and Fertil-
ity Disorders of the Women’s Hospital of the University of
Heidelberg/Germany. The purpose of this exploratory study
with high external validity was to estimate the efficiency of
the Sensiplan method of fertility awareness in aiding sub-
fertile couples to achieve natural conception.
Inclusion criteria
Participating couples in this prospective cohort study were
selected according to the following criteria:
–– at least 1year of unsuccessfully trying to conceive
–– absence of amenorrhea
–– currently receiving no subfertility treatments
––willing to learn and use the Sensiplan method of fertility
awareness
––willing to participate for at least two cycles and to com-
plete and deliver two FAM charts
––willing to fill out three questionnaires over the course of
the study. The questionnaires were designed to collect
information on prior medical history relating to subfer-
tility as well as user satisfaction and competence in use
of the FAM method.
–– no known tubal occlusion
––no known severe OAT (oligoasthenoteratozoospermia,
OAT III).
Study design
During the first study consultation, information was col-
lected about each woman’s previous and current medical
and reproductive history, and on their fertility awareness
knowledge. The charting and use of the Sensiplan method
was also explained. The observation period started with the

1017Arch Gynecol Obstet (2017) 295:1015–1024
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following menstrual period. After the first cycle, a follow-
up consultation was carried out by telephone to enable the
women to discuss their first cycle chart. The women were
asked to return for diagnostic tests during a subsequent
cycle. Basic subfertility investigations were carried out dur-
ing that cycle, including a day 2–5 basic hormonal profile
(blood test). When the patient observed clear, stretchy, and
slippery cervical secretions for the first time in that cycle,
she underwent a transvaginal ultrasound investigation the
following day and blood test was taken to monitor periovu-
latory hormonal levels. A third blood test was taken 1week
later to monitor the hormonal levels of the luteal phase.
83% of male partners had a basic semen analysis.
All couples were requested to stay in the study until
they achieved pregnancy or for up to 8months. The first
chart and the chart of the diagnostic cycle were collected.
Some participants had already scheduled ART treatments
when they became part of the study, and were observed for
a smaller number of cycles before moving on to ART. All
study pregnancies were confirmed by temperature charts
and by ultrasound.
The fertility awareness method
The Sensiplan method consists of recording the pattern of
cervical secretion and changes in basal body temperature.
Women are trained to observe the presence and type of cer-
vical secretions from the vulva over the course of the day
and record sensation and appearance of the secretions prior
to going to bed at night. Basal body temperatures were
measured in the morning after waking up. Self-observation
of the cervical secretions serves as a predictive marker for
ovulation and is confirmed by a temperature rise, which
indicates the closing of the fertility window. The beginning
and the end of the fertile time are determined in the follow-
ing way, and can be considered ‘rules’ for couples trying
to conceive (The guidelines for achieving pregnancy differ
from those for avoiding a pregnancy):
––The beginning of the fertile time is identified by the first
appearance or sensation of cervical secretions on the
vulva and lasts until the third day after the peak day of
secretions.
––The end of the fertile time is additionally confirmed by
the rise in basal body temperature related to the pro-
gesterone surge. The temperature rise is recognized by
three higher readings, all three higher than the previous
six readings and the last one 0.2 °C higher than the pre-
vious six. The elevated temperature retrospectively indi-
cates ovulation has occurred; the temperature remains
elevated until the next menstruation [29, 30].
The methodology is described in detail elsewhere [29].
The behavioral advice given to couples who wish to
conceive is that conception is likely to be highest on those
days when clear, stretchy, and slippery secretions are pre-
sent, as well as on the two consecutive days following this
time. Sexual intercourse should be targeted on days when
cervical secretions are present and for 2days after the peak
secretion day, up to the first higher temperature reading,
even if secretions are no longer present. Couples are told
that they may have intercourse as frequently as they like.
It is recommended that intercourse should occur at least
every 2 or 3 days during the fertile window.
Statistical analysis
Statistical analyses were performed with SPSS 22 and
BiAS for Windows 10. Because the study length of eight
cycles precluded calculation of the median cycle rate for
becoming pregnant, we report the mean cycle rate. The
main results are purely descriptive, with absolute and rela-
tive frequencies, Kaplan–Meier curves and stratified life
tables. The Hall–Wellner method was used to produce a
95% confidence interval. It should be noted that we use the
odds ratio instead of the appropriate term, “relative haz-
ard”, for pregnancy incidence.
As inference statistics we applied Cox regression with
difference as contrast for stratified age and time-to-preg-
nancies. Further, we used Cox regression to adjust for real
age in years in the description of women who became preg-
nant despite secondary subfertility diagnoses such as endo-
metriosis. We stratified our results for duration of childless-
ness and age of the woman according to the relevance of
subfertility co-factors [31].
Due to the study’s exploratory nature, we did not adjust
for multiple testing of each subject.
Study population
In total, 194 patients were recruited into the study. One-
third of the cohort was recruited via the Subfertility Clinic
at the Women’s Hospital of the University of Heidelberg;
the other couples were recruited via advertisements in the
local newspaper. Seven women (3%) became pregnant dur-
ing the last cycle before starting Sensiplan and were hence
excluded from the study, so that the study population con-
sisted of 187 women who had been trying for pregnancy for
at least 1year before study entry. We did not exclude cases
with diminished male fertility (except OAT III if known).
51% of the participants were 35 years or younger
(Table 1). Their ages ranged from 21 to 41 years, with a
mean of 34.7 (SD = 4.9 years) and a median of 35.
48% of the participants had been trying to conceive for
at least 3years (mean of 3.5 years).

1018 Arch Gynecol Obstet (2017) 295:1015–1024
1 3
81% of the women had never been pregnant prior to the
study. 11% had already given birth to one or more children
with the same partner, 4% with another partner, and 9% had
undergone one or more abortions.
96% had received no prior instruction on monitoring
cervical secretions.
Based on the results of the tests of the diagnostic cycle,
the couples were classified according to their subfertility
diagnosis (Table2).
Results
69% (n = 129) of the study participants completed the study,
i.e., they either completed 8 months or became pregnant.
31% of the couples discontinued from the study prior to
completing eight cycles, primarily due to their commenc-
ing subfertility treatments (fertility awareness training was
offered to them while they were on the ART waiting list).
Only 2% of the women withdrew due to problems related to
learning about self-observation of cervical secretions and/
or monitoring their basal body temperature. Another 3%
of the women discontinued the study because it was iden-
tified that pregnancy was no longer possible and a further
3% decided they no longer wished to achieve a pregnancy.
The low lost-to-follow-up rate of 1% indicates good study
implementation (Table3).
Spontaneous pregnancy rate withfertility‑focused
intercourse
The cumulative spontaneous pregnancy rate with fertil-
ity focused intercourse was 38% (95% CI 27–49%) after
8 months of observation (Kaplan–Meier curve with 58
pregnancies) which is above the estimated spontaneous
pregnancy rate without fertility awareness training (Fig.1).
The mean time-to-pregnancy was 6.4 cycles.
Table 1 Age, education and years seeking to become pregnant
(n = 187 women)
Frequency (n) Frequency (%)
Age (years)
≤35 96 51.3
36–40 75 40.1
>40 16 8.6
Education
Low level 14 7.5
Medium level 112 59.9
University degree 61 32.6
Years seeking to become pregnant before study entry
1–2 98 52.4
3–4 59 31.6
≥5 30 16.0
Table 2 Reasons for subfertility (n = 187 women, multiple reasons
possible)
Frequency (n) Frequency (%)
Endocrine reasons 83 44.4
Male factor 44 23.5
Idiopathic 36 19.3
Tubal factor 33 17.6
Endometriosis 15 8.0
Uterine pathology 28 15.0
Other 22 11.8
Table 3 Reasons for study drop-out (n = 187 women)
Absolute fre-
quency (n)
Relative
frequency
(%)
Pregnancy 58 31.0
End of study (8months reached) 71 38.0
Starting infertility treatment 25 13.4
Pregnancy no longer possible (meno-
pause, amenorrhea, hysterectomy)
6 3.2
Lack of time/personal stress 15 8.0
Problems with the Sensiplan method 4 2.1
No longer seeking to become pregnant 6 3.2
Lost-to-follow-up 2 1.1
876543210
cycles
60
50
40
30
20
10
0
pregnancies (%)
Fig. 1 Cumulative natural conception rate after Sensiplan training
(n = 187 subfertile women)

1019Arch Gynecol Obstet (2017) 295:1015–1024
1 3
The 3% spontaneous pregnancy rate during the cycle
directly preceding the training cycle may be considered the
spontaneous pregnancy rate for one cycle without fertility
awareness training. This gives the basic, intrinsic, cumula-
tive pregnancy rate of up to 21.6% during the eight cycles
of study duration (p = 1 − (1 − 0.03)8, conservatively cal-
culated; power to basis 0.97 or 0.978 cycle) for statistical
comparisons.
Spontaneous pregnancy rate depending onage
The spontaneous pregnancy rate depending on age is pre-
sented in Table 4 and Fig. 2. The women were stratified
into three age groups (below 36, 36–40 years and above 40
years). Women 35 years or younger achieved significantly
more spontaneous pregnancies than women aged 36 and
above (log-rank test, p = 0.018). For those under 36 years,
the probability of spontaneous conception after 8 cycles
was 51%; for 36–40 year-olds it was 25% and 20% for those
over 40 years.
If age is considered as metric variable in a Cox regres-
sion model, the chance of becoming pregnant was reduced
by about 8% with each passing year [p = 0.001; Odds ratio
0.92 (95% CI 0.87–0.97)].
Spontaneous pregnancy rate depending ontheduration
ofsubfertility
The participants were also stratified into three groups
according to the length of time spent attempting to achieve
pregnancy prior to the study (1–2 years, 3–4 years, more
than 4 years). For those couples trying to become pregnant
over the previous 1 to 2 years, the pregnancy rate increased
to 56% 8 months after Sensiplan training (significantly
different to the basic pregnancy rate, p < 0.001 in the log-
rank test) (Table5; Fig.3). Amongst the couples who had
tried to achieve pregnancy for between 3 and 4 years, there
was a spontaneous pregnancy rate of 20% after 8 months
(Kaplan–Meier). Amongst those couples with more than
5 years of subfertility, three pregnancies occurred sponta-
neously (11%), all shortly after receiving fertility awareness
teaching.
The basic, intrinsic pregnancy rate of up to 21.6% with-
out fertility awareness training is estimated from the seven
women who became pregnant during the last cycle before
starting Sensiplan, 6 of them attempting to achieve preg-
nancy since 1–2 years and 1 since 3 years.
There is a significant relationship between these two
ordinal variables (Kendall’s tau 0.22, p = 0.001). If age and
length of time seeking pregnancy are each stratified into
three groups and considered together as categorical vari-
ables in a Cox regression model (with difference as con-
trast), seeking pregnancy for more than 2years seems to
be the most important factor [p = 0.006; Odds ratio = 0.38
Table 4 Cumulative probability of natural conception in different age groups after Sensiplan training (n = 187 subfertile women)
Cycle Women at chance (n) Cumulative number of pregnancies Cumulative probability of conception (SE)
<36 years 36–40 years >40 years <36 years 36–40 years >40 years <36 years 36–40 years >40 years
0 96 75 16 0 0 0 – – –
1 93 74 14 13 2 0 0.14 (0.04) 0.03 (0.02) 0
2 74 65 14 19 10 1 0.21 (0.04) 0.15 (0.04) 0.17 (0.07)
3 59 53 10 22 11 1 0.25 (0.05) 0.16 (0.05) 0.17 (0.07)
4 53 49 10 24 13 1 0.28 (0.05) 0.20 (0.05) 0.17 (0.07)
5 48 47 8 29 14 2 0.35 (0.05) 0.21 (0.05) 0.19 (0.12)
6 43 45 7 32 14 3 0.40 (0.06) 0.21 (0.05) 0.20 (0.15)
7 38 44 6 36 15 3 0.46 (0.06) 0.23 (0.05) 0.20 (0.15)
8 33 43 6 39 16 3 0.51 (0.06) 0.25 (0.06) 0.20 (0.15)
876543210
cycles
60
50
40
30
20
10
0
pregnancies (%)
age groups:< 36, 36-40, >40 years
Fig. 2 Cumulative natural conception rate in different age groups
after Sensiplan training (n = 187 subfertile women)

1020 Arch Gynecol Obstet (2017) 295:1015–1024
1 3
(95% CIs 0.19–0.97)]. Despite the limitations of our study
sample, we observed that seeking pregnancy for more
than four years [p = 0.095; Odds ratio = 0.36 (95% CI
0.11–1.19)] and age greater than 35 years [p = 0.069; Odds
ratio = 0.57 (95% CI 0.32–1.04)] seemed to reduce the
chance of becoming pregnant by half. We saw no reason
to stratify below and above 40 years of age (p = 0.672), and
hence we present the pregnancy rates of two age groups, up
to 35 years of age and above 35 years of age (see Table4).
Spontaneous pregnancy rate insecondary infertility
No significant difference was found between the pregnancy
rates of women with primary vs. secondary infertility:
32.8% (42 of 128) for women who had not previously been
pregnant and 31.0% (18 of 58) for women who had already
given birth or who had undergone an abortion.
Spontaneous pregnancy rates bydiagnostic subgroups
Endometriosis, and diminished male fertility, all signifi-
cantly reduce the chances of conceiving naturally (Table6).
Table 5 Cumulative probability
of natural conception after
Sensiplan training by duration
of subfertility (n = 187 women)
Cycle Women at chance (n)Cumulative number of preg-
nancies
Cumulative probability of conception
(SE)
1–2 years 3–4 years ≥5 1–2 years 3–4 years ≥5 1–2 years 3–4 years ≥5 years
0 98 59 30 0 0 0 – – –
1 95 58 28 11 4 0 0.12 (0.03) 0.07 (0.03) 0
2 77 49 27 21 6 3 0.23 (0.04) 0.11 (0.04) 0.11 (0.06)
3 62 40 20 24 7 3 0.27 (0.05) 0.13 (0.05) 0.11 (0.06)
4 56 37 19 27 8 3 0.31 (0.05) 0.15 (0.05) 0.11 (0.06)
5 51 34 18 34 0 3 0.40 (0.05) 0.15 (0.05) 0.11 (0.06)
6 44 33 18 37 9 3 0.44 (0.06) 0.18 (0.06) 0.11 (0.06)
7 40 31 17 41 10 3 0.50 (0.06) 0.20 (0.06) 0.11 (0.06)
8 35 30 17 45 10 3 0.56 (0.06) 0.20 (0.06) 0.11 (0.06)
876543210
cycles
60
50
40
30
20
10
0
pregnancies (%)
seeking for pregnancy groups: 1-2, 3-4, >4 years
Fig. 3 Cumulative natural conception rate after Sensiplan training by
duration of subfertility (n = 187 subfertile women)
Table 6 Natural conception
rates after Sensiplan training by
diagnostic subgroups adjusted
for age (n = 187 women)
a Log-rank test without adjustment for age
b Cox regression after adjustment for age in years
Women with preg-
nancy
Women without
pregnancy
p valueap valuebOdds ratio
Endocrine reasons 29/58 50% 54/129 42% 0.292 0.426 1.23
Male factor 6/58 10% 38/129 30% 0.021 0.026 0.38
Idiopathic 13/58 22% 23/129 18% 0.925 0.704 0.89
Tubal factor 11/58 19% 22/129 17% 0.962 0.510 0.79
Endometriosis 1/58 2% 14/129 11% 0.043 0.077 0.17
Uterine pathology 6/58 10% 22/129 17% 0.234 0.449 0.72
Other 3/58 5% 19/129 15% 0.153 0.193 0.46

1021Arch Gynecol Obstet (2017) 295:1015–1024
1 3
Subjective assessment oftheinfluence ofthefertility
awareness method onthewell‑being ofthewomen
A questionnaire on the assessment of the influence of the
Sensiplan method on the well-being of the participant was
completed at the end of study participation (n = 171, multi-
ple answers possible). 78% of the participants reported that
the training in identifying their fertility window positively
affected their feelings towards and perceptions of their bod-
ies. 53% reported that this knowledge had had a positive
impact on their self-image as a woman. 11% of the women
stated that their partnership had been negatively impacted
through the observations of the fertile time. 16% of the
women reported a negative effect on sexuality. Only 7%
of women described the FAM method as bothersome or
reported that they did not like to plan intercourse according
to their fertile time. At the end of the study, 82% of patients
stated that they planned to continue using the Sensiplan
method or that they would use the method again if they
were planning another pregnancy.
Discussion
38% of subfertile couples (who had been trying for preg-
nancy since an average of 3.5 years) were successful in
achieving a pregnancy after receiving training in the Sen-
siplan method. In those couples who had been trying to
achieve a pregnancy for between 1 and 2 years, the preg-
nancy rate increased to 56% after 8months following FAM
training. Duration of non-conception for more than 2years,
maternal age above 35, endometriosis and male subfertility
significantly reduced the chances of conceiving naturally.
Does fertility awareness knowledge increase
thespontaneous pregnancy rate insubfertile couples:
more thanjust expectant management?
This observational cohort study lacks a control group. The
intrinsic, basic, natural conception potential without fertil-
ity awareness training can be estimated, however. We con-
sider the rate of 3% spontaneous pregnancies (n = 7) in the
cycle directly preceding study entry to be the spontaneous
pregnancy rate per cycle without fertility awareness train-
ing, yielding a cumulative estimated pregnancy rate of up
to 21.6% (maximum) after 8months.
An observational study by Snick etal. on spontaneous
pregnancy rates in 726 couples attempting pregnancy for
1year showed a live birth rate of around 25% after another
12 months and 52.45% after 36 months [32], confirming
computational prognostic models [33]. Our comparatively
higher pregnancy rates amongst couples using Sensiplan
suggest that couples benefit from training in how to iden-
tify the fertile time through self-observation.
There are three randomized controlled studies on the
effect of timed intercourse in the fertile window on preg-
nancy rates. Robinson etal. observed 305 subfertile women
with and 348 without use of a fertility monitor, which
measures urine E1G and LH levels [34]. After two cycles
the pregnancy rate amongst women able to identify their
fertile time was significantly higher (23 vs. 14%) than
amongst the controls. The second randomly controlled trial
is the Oxford conception study, which has not yet published
final results [35]. In a randomized trial with 143 couples
with proven fertility, Stanford et al. found no significant
impact of the respective FAM vs. frequent intercourse [36].
Further randomized controlled trials studying the effect of
fertility awareness training with self-observation methods
are needed [37].
Moreover, several probability-of-conception studies
have shown that the phase of peak fertility is rather nar-
row (2–3days per cycle), and that conception probabilities
quickly decline even within the fertile window [11, 20, 38,
39]. This physiological fact represents a further reason for
targeted intercourse.
There is already considerable evidence suggesting that
awareness of the fertile window is an effective method for
enhancing the probability of conception in couples starting
to try for pregnancy, and is likely to be more effective than
expectant management [21, 22, 25, 40]. Evers analyzed a
Cochrane database of hypothetical cumulative spontane-
ous pregnancy rates without controlled knowledge of the
time of peak fertility, reporting that the time-to-pregnancy
for 20% of women who were able to become pregnant was
1month and for 74% of that group was 6months [31]. In
comparison, 42% of women who became pregnant while
using the Sensiplan method were pregnant in 1 month
and 75% were pregnant within 3 months, suggesting that
women conceive more rapidly with fertility awareness
knowledge [22].
However, further randomized trials on FAM in subfer-
tile couples are needed: The Cochrane review undertaken
by Grimes etal. in 2004 only addressed the contraceptive
effectiveness of FAMs [41]. Furthermore, it was based on
three old, low-quality studies.
Stress related totiming intercourse
As timed intercourse may cause stress, it is not recom-
mended in several medical guidelines [5, 42]. These recom-
mendations are based on one study only, a mail survey with
27 participants that has been criticized because of its poor
quality [43]. Instead, the guidelines recommend intercourse
every other day throughout the whole cycle. The impact of

1022 Arch Gynecol Obstet (2017) 295:1015–1024
1 3
the stress caused by recommending continuous intercourse
throughout the whole cycle has not been investigated to
date either.
The argument for withholding knowledge about the
fertile time for that reason is only theoretical, since most
couples in the situation of seeking to become pregnant try
to detect their fertile window in some fashion, but not all
methods practiced provide useful and accurate information.
An Australian study that followed 282 patients seeking
subfertility care from ART clinics found that 87% actively
tried to improve their fertility awareness knowledge using
one or more information resources, and that most believed
that they had targeted sexual intercourse during their fertile
window. In fact, only 13% of the participants were able to
correctly identify the fertile time [43, 44]. A further study
involving 80 subfertile women seeking fertility care found
that 76% could not accurately identify the fertile window
[45]. These results suggest that poor fertility awareness
knowledge may be one of the factors preventing couples
from achieving their conception potential.
In addition, as any fertility investigation and treatment
may cause stress, it is up to each couple to decide the suit-
able way to deal with their subfertility.
The accuracy ofexisting fertility awareness knowledge
While many women believe that they know when they are
fertile, this has been shown to be inaccurate [43, 46, 47].
Sievert etal. interviewed 53 women who thought that they
could identify their fertile window. Participants were asked
to identify their fertile days over a period of 87 cycles [48].
Sievert etal. found that the women relied on the common
knowledge on the fertile days which was obviously poor.
They concluded that “for most women, ovulation is con-
cealed” even if they think they know it. This supports our
suggestion that women should be taught how to identify the
fertile time correctly.
80% of women who were having trouble conceiving and
who had attended a course led by a trained teacher of fertil-
ity awareness methods could identify the fertile time during
their menstrual cycle [45]. The authors, therefore, propose
that fertility awareness knowledge should be integrated into
routine preconception consultations and into teaching of
health professionals.
The observation ofcervical secretions: anaccurate
predictor ofthefertile time
A considerable amount of data suggests that observation of
cervical mucus changes can closely approximate the day of
ovulation, is easy to learn and suitable for a large cross-sec-
tion of women [2, 9, 10, 15, 18, 49]. Scarpa etal. found in a
time-to-pregnancy study with 193 women that the presence
of cervical secretions accurately predicts the fertile time,
and that the presence of cervical secretions on the day of
intercourse is a better predictor of the likelihood of concep-
tion than targeted intercourse at likely time of ovulation
[38].
The ASRM guidelines state that “the fertile time is a
6-day interval that ends on the day of ovulation and corre-
lates with the volume and character of cervical secretions.”
The guidelines additionally state that determining or pre-
dicting the time of ovulation may be useful for couples try-
ing to conceive [5, 23].
Dunson etal. found that the presence of cervical secre-
tions is an even better fertility marker than LH kits. Cer-
vical secretions identify the whole fertile window more
accurately, because they indicate more days when sexual
intercourse may result in pregnancy. In their probability-of-
conception analysis of a large European database of cycles,
they identified that those couples with a single episode of
sexual intercourse during the fertile time needed a larger
number of cycles to achieve conception [50], see also [51,
52]. These findings indicate that the observation and moni-
toring of cervical secretions to identify the fertile time is a
useful way to identify days when there is a high probability
of conception if intercourse takes place.
The psychological impact ofteaching fertility awareness
tosubfertile couples
Klann et al. noted a positive impact on self-awareness
when the FAM is used to avoid pregnancy [7]. The present
study is the first one that has investigated the psychologi-
cal impact of the use of the Sensiplan fertility awareness
method on a population of subfertile women based on a
personal assessment. The results were that 78% of women
assessed the effect of the method on their own body aware-
ness as a positive one and 53% positively rated the influ-
ence on their self-image as a woman. While a minority of
couples experienced a negative effect on their relationship
(11%) and sexuality (16%) when taught fertility awareness
methods, this is not the case for the majority of couples.
Providing fertility awareness asanintegral part
ofthemanagement ofsubfertility
As most pregnancies are likely to occur during the first
few cycles of using the Sensiplan method, subfertile cou-
ples should be given a chance of achieving pregnancy for
at least six cycles prior to any intervention. After receiv-
ing basic investigations for subfertility, couples could be
encouraged to observe their fertile window to optimize
their chances of achieving a pregnancy spontaneously,
especially in those cases of unidentified or minor reasons
for subfertility and for those women who are known to have

1023Arch Gynecol Obstet (2017) 295:1015–1024
1 3
sufficient ovarian reserve [53–55]. According to Evers, two
important questions need to be addressed before any treat-
ment for subfertility is offered [31]: Has sufficient exposure
to the chance of conception taken place? Are cost-effective,
safe, and reliable treatments available?
The authors believe that the integration of fertility
awareness into subfertility care is likely to lead to signifi-
cant cost savings in subfertility management. Further stud-
ies on the acceptability of learning fertility awareness in the
condition of subfertility are recommended.
Conclusion
Training women to identify their fertile window in the
menstrual cycle seems to be a reasonable, non-invasive and
safe first-line therapy in the management of subfertility.
Sensiplan is a standardized fertility awareness method that
has the potential to improve spontaneous pregnancy rates in
subfertile couples.
Acknowledgements The authors cordially thank Sylvia Heil-
Schlehuber for her dedicated assistance and her valuable comments.
The study was funded by the Jung-Stiftung für Wissenschaft und
Forschung.
Compliance with ethical standards
Conflict of interest The authors declare that they have no conflict
of interest. They do not have any financial relationship with the or-
ganization that sponsored the research. They have had full control of
all primary data and they agree to allow the Journal to review the data
if requested.
Ethical approval Ethical approval was given by the Section of Natu-
ral Fertility of the German Society of Gynecological Endocrinology
and Fertility Medicine at the University of Heidelberg. The study was
conducted in accordance with the ethical principles of the Declaration
of Helsinki of 1964 and its later amendments.
Informed consent Informed consent was obtained from all indi-
vidual participants included in the study. They were free to withdraw
at any time.
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