Helping You Monitor Your Fertility

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"Fertility awareness allows women to track one or more symptoms related to their fertility. By charting these symptoms, the results can be interpreted to calculate and even anticipate the time of ovulation when pregnancy is most likely to occur."


Ovulation Calendar


There are many symptoms that you can track on symptothermal charts. The two most common are cervical mucus and basal body temperatures. Ovulation tests that detect LH levels are also commonly used and charted. When ovulation testing is done, the other symptoms can be used to help suggest when to test. Additional symptoms can also be charted to offer a double check of these primary symptoms.

The different symptoms that can be recorded and charted as indicators of fertility are summarized below. Which you use may depend upon your objective.

Symptom Equipment Requires Actions Proven Effective? Predicts Ovulation Beforehand Identifies Ovulation Afterwards
Basal Body Temperatures Thermometer Daily Yes No Yes
Cervical Mucus None Daily Yes Yes Yes
LH Ovulation Tests Ovulation Predictor Kits Some Days Yes Yes No
Fertility Monitor Monitor plus test strips Daily Yes Yes Yes
Cervix Observations None Daily Yes Yes No
Saliva Ferning Microscope Daily Questionable Yes No
Rhythm Method None Infrequent For Some Women Yes Yes

For couples trying to conceive, symptoms that identify ovulation in advance are particularly important. This is why cervical mucus is very common. Basal body temperature charting cannot detect ovulation until after it has already occurred. Although it does not allow couples a chance to try to conceive based upon this late information, BBT charting is still useful as it can help identify ovulation and show that conception was possible. It is also popular since the sustained or triphasic temperature pattern can offer an advanced clue of successful conception.

For couples trying to avoid pregnancy, symptoms that isolate the fertile interval are most important. It is recommended to use at least one symptom that identifies the start of the fertile days surrounding ovulation and one that identifies the end of this period. Cervical mucus is one way to detect approaching fertility. Basal body temperature charting is useful to identify ovulation after the fact. This can be useful to understand when the likelihood of conception is significantly reduced. As a means of postponing pregnancy, fertility awareness advocates that couples avoid sexual intercourse during the fertile days.

Basal Body Temperature

What you must do: Take your temperature once a day immediately after waking.

Necessary equipment: An accurate thermometer. A good digital thermometer with 0.1 degree resolution or a special basal thermometer can be used. Costs about $10 (USD).

Relation to ovulation: Temperature charting can identify ovulation only after it has already occurred.

Interpretation: Temperatures are normally charted so that a shift in readings can be looked for. There are several techniques that can help confirm a shift indicative of ovulation.

Effectiveness: It is well accepted that temperature changes indicate ovulation. To be effective, temperature charting requires consistency. Other factors such as illness, environmental conditions, etc. can sometimes influence temperature and make the 0.5 degree shift due to hormonal changes harder to detect.

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Cervical Mucus

What you must do: Each day take a sample of cervical mucus from your vagina and note its consistency, color, and texture. The observations can be recorded on a symptothermal chart to compare changes from day to day.

Necessary equipment: No equipment necessary.

Relation to ovulation: Cervical mucus begins to take on fertility characteristics before ovulation. It can be used as a predictor of ovulation before it occurs.

Interpretation: Mucus transitions from infertile to fertile characteristics. Ovulation is anticipated when the cervical mucus begins to exhibit fertile characteristics.

Effectiveness: Cervical mucus has been proven to be an indicator of fertility. Once you become accustomed to the changes throughout the menstrual cycle, this symptom can be used very effectively.

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LH Ovulation Test

What you must do: Test your urine using ovulation test daily until testing positive. You can estimate when you should start testing by charting other symptoms to identify the onset of ovulation or by using a rhythm method as a rough estimate of ovulation.

Necessary equipment: Requires over the counter ovulation predictor kits. Often requires multiple tests per cycle. Costs $0.50 to $1.00 per one time use test (USD).

Relation to ovulation: Lutenizing hormone surges immediately before ovulation. Ovulation tests work by testing for this hormone in urine.

Interpretation: An ovulation test identifies ovulation 24-36 hours before it occurs. Once testing positive, you can assume that your chances of getting pregnant will be highest over the course of the next 48 hours.

Effectiveness: The LH surge is a good indicator of ovulation. These tests can accurately help identify ovulation.

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Fertility Monitor

What you must do: Use test strips to test your urine each morning with a fertility monitor device. The test strips are inserted into the device and it reads the results for you.

Necessary equipment: A monitor like the Clearblue Easy Fertility Monitor which costs between $150 and $200. You must also purchase test strips regularly so that you can test your urine daily.

Relation to ovulation: Because the fertility monitor tests for two different hormones, it can detect the start and end of fertility.

Interpretation: The fertility monitor shows one of three states indicative of low fertility (L), high fertility (H), and peak fertility (P).

Effectiveness: The hormones tested are good indicators of ovulation. Sometimes the LH surge can be missed and ovulation will not be identified. The onset of fertility is usually identified though especially if the readings are charted so that cycle history can be taken into consideration.

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Cervix Symptoms

What you must do: Use your fingers to internally check your cervix for height, consistency, and diameter. These symptoms can be tracked from day to day on a symptothermal chart with other indicators.

Necessary equipment: No equipment necessary.

Relation to ovulation: The cervix changes prior to ovulation. This technique can predict ovulation several days in advance as the cervix begins to assume more fertile characteristics.

Interpretation: The cervix will become soft, wet, open, and high as ovulation approaches. When the cervix begins to exhibit these traits, ovulation is imminent.

Effectiveness: Studies have linked changes in the cervix to the onset of ovulation.

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Saliva Ferning

What you must do: Take a sample of saliva and allow it to dry on a slide. Use a handheld microscope to check the saliva for ferning patterns.

Necessary equipment: Requires a handheld microscope. Costs $30 to $50 (USD).

Relation to ovulation: Around the time of ovulation the sodium levels in the body rise. This is apparent in the saliva and causes crystallization (or ferning) patterns after drying.

Interpretation: The lack of ferning patterns indicates low fertility levels for the given day. Ferning patterns should develop as ovulation nears and the chance of pregnancy increases. These patterns can vary though and are not always present only around ovulation. Other symptoms should also be charted to offer a more complete estimate of fertility.

Effectiveness: Studies have shown mixed results linking ferning patterns to ovulation. It certainly does not work for everyone. As a result, it should not be used exclusively. Other more reliable symptoms should also be monitored.

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Gap Method

What you must do: Both you and your partner must take your temperatures once a day immediately after waking around the same time.

Necessary equipment: An accurate thermometer. A good digital thermometer with 0.1 degree resolution or a special basal thermometer can be used. Costs about $10 (USD).

Relation to ovulation: Temperature charting can identify ovulation only after it has already occurred.

Interpretation: Both temperatures are recorded and the difference, or gap, between the two values are plotted. You should monitor this temperature gap and watch for it to diverge.

Effectiveness: It is well accepted that temperature changes indicate ovulation. It is unclear whether introducing a partner's temperature will reduce the variation of temperature data or simply introduce more variables and make it worse. An initial research study found it offered value.

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Rhythm Method

What you must do: Record the start of your menstrual periods. No daily record keeping is necessary.

Necessary equipment: Any type of calendar.

Relation to ovulation: The rhythm method makes generalizations about ovulation to attempt to predict when it will likely occur. It assumes that a given cycle will be approximately average in length and that the luteal phase length will be fixed (usually assumed to be 14-days).

Interpretation: The method projects the start of the next menstrual cycle based upon historic information about cycle length. It then counts backwards from that date to account for the luteal phase. The day of ovulation is estimated this way. A window of probable high fertility is added around this date based upon the degree of variation in your cycle.

Effectiveness: The rhythm method is not very effective. Its success varies widely and depends upon the consistency of the female cycle. The estimates are often significantly off or extremely vague for women with irregular cycles. It can be used when tracking other symptoms as an initial estimate of ovulation. When the assumptions made by the method are valid, it can make fair estimates.

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