Natural Family
Planning
At present, the four natural methods
used for family planning are the rhythm, cervical
mucus, basal body temperature, and symptothermal methods.
The rhythm method involves calculation of the probable
fertile period on the basis of the lengths of previous
menstrual cycles. The more recently developed methods
identify the fertile period from either the basal
body temperature or the characteristics of the cervical
mucus or both. These primary signs may be complemented
by other signs detected by the woman as recurring
in her own pattern of fertility (for example, breast
sensitivity, abdominal pain, intermenstrual bleeding,
and changes in the position, opening, and texture
of the cervix).
Rhythm
The rhythm or calendar method is one in which the
probable days of fertility are estimated from the
cycle records of the previous 6-12 months. The earliest
day on which a woman is likely to be fertile is computed
by subtracting 11 days from the length of her longest
cycle. These calculations therefore indicate the beginning
and end of the women's fertile period. For example,
if the woman's menstrual records show that her shortest
cycle has been 25 days and her longest cycle 31 days,
her first fertile day, day 20 (31-11). In other words,
for this example, the fertile phase would be considered
to last from about day 7 until day 20. During her
fertile (unsafe) days she would have to abstain from
intercourse to avoid pregnancy. This method, however,
provides only a very rough estimate of the fertile
time.
Cervical
mucus method
In order to use the cervical mucus method (sometimes
called Billings' or ovulation method), a woman must
learn to recognize the characteristic changes in the
cervical mucus discharge that occur during the cycle.
Most women experience a sensation of dryness in the
vgina for a few days following the menstrual period
(the relatively infertile of early infertile phase).
Then, they notice the appearance of sticky mucus,
followed by several days during which the vagina feels
increasingly wet. The last day of wetness or lubrication
is called the peak day, and occurs when the estrogen
is at its highest level. By this time, the cervical
mucus has become very wet, clear or cloudy, and slippery,
and looks like raw egg white. After the peak day,
the mucus rapidly changes under the influence of progesterone
to become thick, or it may disappear completely, and
the woman again experiences vaginal dryness. The fertile
phase of the cycle begins at the time the wet mucus
appears. Third day after the peak wet mucus mark the
end of the fertile phase. The postovulatory or late
unfertile phase of the cycle begins on the fourth
day after peak mucus and continues until the first
day of menstruation of the next cycle. When a couple
wants to avoid pregnancy, they should abstain from
intercourse from the day of appearance of wet cervical
mucus until after the third complete day following
the peak day of mucus. In addition, couples should
avoid intercourse on consecutive days during the early
'dry' phase, since residual ejaculate may be confused
with mucus.
The
basal body temperature method
The basal body temperature method is based on the
change in body temperature that occurs shortly after
ovulation, associated with secretion of progesterone
by the corpus luteum. After ovulation, the body temperature
increases and remains at the higher level until the
next menstruation. The postovulatory (late) infertile
phase of a woman's cycle begins on the third day after
the temperature shift is observed. Women using the
basal body temperature method need to record their
temperature at rest, at the same time each day, so
that they can recognize the infertile time of each
cycle. The method can be used only to identify the
postovulatory infertile phase of the cycle. When a
couple is using the method to avoid pregnancy, they
must avoid intercourse until the third day after the
rise in temperature.
The
symptothermal method
The symptothermal method combines recording of the
basal body temperature with the observation of the
characteristics of the cervical mucus and other physiological
indicators of ovulation, such as tenderness of the
breasts, mid-cycle pain, spotting or bleeding, and
abdominal heaviness around the time of ovulation.
Women may also observe changes in the position, degree
of opening, and texture of the cervix, or include
calendar calculations in their practice of the method
to avoid pregnancy; they abstain from intercourse
from the appearance of wet cervical mucus until the
third day of elevated temperature or the fourth day
after the peak day of mucus, whichever comes later.
Period of abstinence
The use of natural family planning method requires
a period of abstinence from intercourse at the time
the woman is fertile. The length of abstinence varies
depending on the length of the woman's cycle, the
signs and symptoms in the cycle, and the method used.
The longest period of abstinence is required in the
strict application of the basal body temperature method,
which requires that a couple have intercourse only
during the postovulatory infertile phase. In the symptothermal
method, the length of the period of abstinence varies
according to whether the couple uses calculation of
the fertile period, cervical mucus characteristics,
changes in the cervix, or a combination of signs to
identify the beginning of the fertile period. Abstinence
required in a hypothetical 28-day cycle for each of
the four methods. Although the actual fertile phase
of the cycle is only about 6-8 days, the number of
days of abstinence required varies from 8-17 days,
depending on the method used.
Abstinence from intercourse can have positive and
negative effects on a couple's relationship.
