Symptothermal Method

How it works

Three signs are assessed together:

• Basal body temperature: Rises by 0.2–0.5 °C after ovulation due to progesterone. The rise shows that ovulation has occurred.
• Cervical mucus: Becomes clear, slippery and stretchy before ovulation. This marks the start of the fertile window.
• Cycle records: Past cycle lengths provide additional information.

Mucus marks the start of the fertile window and the temperature rise marks its end. Used together, they define the window more accurately. Sperm can live for up to 5 days. For this reason, once mucus changes begin, sex is avoided or condoms are used. The safe period begins after the temperature rise has lasted for 3 days.

Measuring and observation rules

Basal temperature:

• Every morning at the same time, before getting out of bed, after at least 3 hours of sleep.
• A special basal thermometer.
• Always the same site (oral, vaginal or rectal).

Cervical mucus:

• Checked every day after using the toilet or with a finger.
• Recorded as dry, sticky, creamy, or clear and slippery.
• Clear, stretchy mucus indicates the fertile window.

Records:

• A chart is kept for at least 3 cycles.
• An app or a paper chart can be used.
• Illness, alcohol and lack of sleep are noted.

At SoftCare, your first records are reviewed together with you. The method cannot be relied on until it has proven reliable for you.

Effectiveness

With trained, perfect use (Sensiplan study):

• First-year pregnancy rate about 0.4%.
• With typical use (trained), about 1.8–2%.

With untrained or irregular use:

• With typical use, it can rise to 12–24%.

These rates are not as good as LARC methods (below 1%). However, when learned correctly, it may perform better than typical use of the combined pill. At SoftCare, the method is not recommended without training. The gold IUD remains our first choice.

Limitations

• It requires daily discipline. Forgetting or measuring late causes errors.
• Illness, stress, alcohol and shift work distort temperature readings.
• With irregular periods, interpreting mucus becomes difficult.
• It is not reliable during breastfeeding or perimenopause.
• It does not protect against STIs.
• It requires training. Self-teaching increases the risk of errors.
• Sex must be avoided or condoms used during the fertile window. This can be difficult for some couples.

Because of these limitations, at SoftCare the method is not discussed as protection on its own. It is considered for learning purposes or together with an additional method.

Who it can be discussed with

• Those who want to learn about their fertility cycle
• Those planning a pregnancy
• Those who do not want to use hormones and can keep daily records
• Those willing to receive training

Who it is not suitable for:

• Those with irregular periods
• Shift workers
• Those who are breastfeeding
• Those who absolutely want to avoid an unintended pregnancy
• Those at high risk of STIs
• Those who will not be able to keep daily records

At SoftCare, LARC or condoms are discussed directly with these patients.

STI protection and emergency contraception

The method does not protect against STIs. A condom should be added. If unprotected sex happens on a fertile day, emergency contraception is explained. The levonorgestrel pill can be used within 72 hours, ulipristal acetate within 120 hours, and a copper, gold or hormonal IUD within 5 days. At SoftCare, these options are discussed in advance.

More effective alternatives

At SoftCare, these options take priority over the symptothermal method:

• Gold IUD: Hormone-free, 5 years, no risk of forgetting.
• Hormonal IUD: For heavy bleeding.
• Contraceptive implant: 3 years.
• Condom: STI protection.
• Combined pill: Effective with regular use.

The symptothermal method can be explained to patients who want to learn about their fertility. It is not recommended on its own. Training and record-keeping are essential.

Our approach at SoftCare

At SoftCare Clinic, the symptothermal method is discussed with patients who want to learn about their fertility. It is not recommended as a contraceptive method on its own. You are taught how to measure temperature and observe mucus. Records for at least 3 cycles are requested. Their reliability is assessed. The gold IUD is our first recommendation. If a patient still wants to use the method, written information is given on its effectiveness, the need for training and emergency contraception options. Adding a condom is recommended. If there is an STI risk, testing is planned. Switching to a more effective method is discussed at every check-up.

Appointments: +90 212 241 30 10 · softcareclinic.com

References

• 1. Frank-Herrmann P, et al. The effectiveness of a fertility awareness based method to avoid pregnancy in relation to a couple’s sexual behaviour during the fertile time: a prospective longitudinal study. Hum Reprod. 2007;22(5):1310–1319.
• 2. Centers for Disease Control and Prevention (CDC). Contraception and Birth Control Methods.
• 3. World Health Organization (WHO). Family planning/contraception methods.
• 4. Trussell J. Contraceptive failure in the United States. Contraception. 2011;83(5):397–404.
• 5. American College of Obstetricians and Gynecologists (ACOG). Fertility Awareness-Based Methods.
• 6. T.C. Sağlık Bakanlığı. Gebeliği Önleyici Yöntemler.
• Note: Effectiveness rates vary depending on training. At SoftCare, the symptothermal method is not recommended on its own; the gold IUD and other LARC methods take priority. This reference list is for information purposes.

A citation does not mean that SoftCare wrote that text.

Medically reviewed by Op. Dr. Şükrü Sanus, Obstetrician & Gynecologist · Last medical review: 2 October 2026