Progesterone Levels: What Do They Tell You in Pregnancy and Ovulation?

Short Answer

There is no single progesterone value that "should be" reached in pregnancy for everyone; laboratories' pregnancy ranges are very wide. According to the NICE NG126 guideline, progesterone is not used to determine whether a pregnancy is healthy or to identify an ectopic pregnancy. Outside pregnancy, progesterone is mostly checked to confirm ovulation; according to ASRM, a value above 3 ng/mL indicates that ovulation has occurred recently. Interpretation is based on the laboratory range on your report.

How does it appear on your report?

• Name: The report says "Progesterone" (Turkish: "Progesteron").
• Unit: Most reports use ng/mL. Some laboratories report nmol/L. For example, the TEMD 2025 guideline gives 0.6 ng/mL as the equivalent of 2 nmol/L.
• A test not to be confused with it: "17-OH progesterone" is a different test. According to TEMD 2025, it is checked to investigate adrenal gland diseases.
• Phase-specific range: Laboratories may give separate ranges for the follicular phase, luteal phase and pregnancy.

The "Tahlillerim" (My Tests) screen in e-Nabız (Türkiye's national health record app) lists results together with reference values. Results outside the range are highlighted in color. However, the color may not take into account which day of your cycle you gave blood or whether you are pregnant. So read the result together with the date.

Normal values and reference range

Condition	Example range (ng/mL)	Source
Follicular phase	0.2–1.6	Michigan Medicine
Luteal phase	3.0–22.0	Michigan Medicine
Mid-luteal phase	5.0–22.0	Michigan Medicine
Using birth control pills	Below 0.2	Michigan Medicine
Pregnancy, 1st trimester	11.22–90.0	MU Health Care
Pregnancy, 2nd trimester	25.55–89.40	MU Health Care
Pregnancy, 3rd trimester	48.40–422.50	MU Health Care
Male	0.2–0.9	Michigan Medicine

Even the luteal phase ranges of two laboratories differ from each other. At MU Health Care, the luteal range is 3.34–25.56 ng/mL.

A reference range covers 95% of healthy people; about 1 in 20 healthy people may fall slightly outside the range.

What should progesterone be in pregnancy?

Short answer: There is no single target number. The reasons are:

• Its source changes: According to the Total Testing Process Guide, in early pregnancy progesterone is produced by the corpus luteum, stimulated by hCG. Later, the placenta takes over this role.
• The range is very wide: In one example laboratory, the first-trimester range is 11.22–90.0 ng/mL.
• It is not a diagnostic test: NICE NG126 recommends that progesterone not be used to diagnose a viable or ectopic pregnancy while serial beta HCG is being monitored.
• The Turkish guideline is cautious too: According to the PERİDER-TJOD 2025 guideline, the use of progesterone when no sac is seen inside the uterus is controversial. The guideline states that it has no place in routine practice. The difference in levels between spontaneous and assisted pregnancies also makes interpretation harder.
• Only for predicting outcome: According to the same guideline, in threatened miscarriage a single first-trimester value below 12 ng/mL has been associated with the likelihood of miscarriage. This information can be used to predict the course, not for diagnosis.

This threshold and the example laboratory's lower limit for pregnancy are very close to each other. In other words, values around 12 ng/mL can also be seen in healthy pregnancies. So a single low result does not by itself mean bad news.

What is the decision on progesterone medication based on? NICE NG126 recommends progesterone treatment for women with an intrauterine pregnancy confirmed by ultrasound who have bleeding and have had a previous miscarriage. In other words, the criterion is this clinical picture, not the blood level. PERİDER-TJOD 2025 also does not recommend natural progesterone in threatened miscarriage without a previous history of miscarriage. The decision to start or stop medication is always made by your doctor.

Progesterone for ovulation

• When is it checked? NICE NG257 (March 2026) recommends measuring on day 21 of a 28-day cycle, that is, in the mid-luteal phase.
• If your cycle is not 28 days: According to ASRM 2021, the measurement is made about 1 week before the next period instead of on a fixed day 21.
• If your cycle is long and irregular: NICE recommends measuring later; for example, on day 28 of a 35-day cycle. The measurement is then repeated weekly until the next period starts.
• How is it interpreted? According to ASRM, a value above 3 ng/mL indicates that ovulation has occurred recently.
• Why does the value fluctuate? In the luteal phase, progesterone can change up to 7-fold within a few hours. So a single measurement confirms ovulation but does not measure the "quality" of the luteal phase.
• Luteal phase deficiency: According to the ASRM 2026 opinion, this is a clinical diagnosis defined by a luteal phase lasting 10 days or less. It has not been proven to be an independent cause of infertility or recurrent miscarriage.

What does a low value mean?

• Wrong timing: If the blood was drawn before ovulation, the value may come out low. That is why ASRM recommends measuring about 1 week before the next period.
• Follicular phase, menopause and birth control pills: Low progesterone is expected in these situations.
• No ovulation in that cycle: According to ASRM 2021, the most common causes are PCOS, obesity, the menopausal transition, weight change, excessive exercise, thyroid disorders and high prolactin.
• A low value in pregnancy: On its own, it does not establish a diagnosis of miscarriage or ectopic pregnancy. It is evaluated together with the 48-hour change in beta HCG and ultrasound.

What does a high value mean?

• Luteal phase: Progesterone rises after ovulation; this is normal.
• Pregnancy: The value increases as pregnancy progresses. In the example laboratory, the third-trimester range is 48.40–422.50 ng/mL.
• Unexpected elevation outside pregnancy: Your doctor will first ask about the timing of the measurement and the hormone medications you use.

When read together

• Progesterone + beta HCG: In early pregnancy, what is decisive is the 48-hour change in beta HCG and ultrasound. Details are in the article Beta HCG Values.
• Progesterone + ovulation test: After seeing the LH surge at home, progesterone checked about 1 week before the next period confirms ovulation. See Ovulation Test and LH.
• Low progesterone + irregular periods: Suggests an ovulation disorder. FSH, LH, prolactin and TSH may be ordered.
• Regular periods + low progesterone: According to the 2023 International PCOS Guideline, an ovulation disorder can also be present with regular cycles. If needed, progesterone is used to confirm this.

Preparing for the test

• Calculate the timing: Note the first day of your last period and your average cycle length. The day of the blood draw is chosen accordingly.
• Record the date of your period after the measurement: Interpretation is more accurate based on when the next period starts.
• Medications: If you use a hormone-containing medication or birth control method, mention it when the test is ordered.
• Biotin: According to the Total Testing Process Guide, high-dose biotin can interfere with immunological tests. For people taking 5–10 mg a day, waiting at least 8 hours is recommended.
• Fasting: Ask your laboratory whether fasting is separately required for progesterone.

Which doctor, which test?

• Obstetrics and Gynecology: The first point of contact for bleeding in pregnancy, inability to conceive and menstrual irregularity.
• Reproductive endocrinology and infertility: Evaluates couples who have been unable to conceive for a long time.
• What may be ordered in pregnancy: Beta HCG 48 hours apart and transvaginal ultrasound.
• What may be ordered for an ovulation problem: FSH, LH, prolactin, TSH and, if needed, androgen measurements.
• In recurrent miscarriage: The evaluation is a separate matter; a single progesterone measurement does not answer this question.

In Türkiye

• National guideline: The 2025 joint threatened miscarriage guideline of PERİDER and TJOD states that progesterone measurement has no routine role and may be considered only for predicting the outcome.
• Drug safety: According to the same guideline, TİTCK (Turkish Medicines and Medical Devices Agency), in a letter dated 20.09.2024, suspended the licenses of drugs containing 17-alpha hydroxyprogesterone. The reason is a reported increase in cancer risk in people exposed to this drug in the womb. PERİDER does not recommend this molecule in threatened miscarriage.
• Data gap: According to the guideline, there is no comprehensive study in Türkiye showing the frequency of threatened miscarriage.
• e-Nabız: You can see your progesterone results with their dates. Separately noting the cycle day on which you gave blood makes interpretation easier.

When should you seek emergency care?

• If there is heavy bleeding, dizziness or marked abdominal tenderness in pregnancy, go to the emergency department. The PERİDER-TJOD guideline calls for a repeat ultrasound with these findings.
• If shoulder-tip pain, a feeling of fainting or a rapid pulse occurs together with a positive pregnancy test, call 112 (the emergency number in Türkiye).
• If bleeding in pregnancy is accompanied by cramping pain, get evaluated the same day. According to the guideline, painful heavy bleeding has a worse course than light spotting.
• If the laboratory or your doctor has called you about your result, call back the same day.
• A single low progesterone result without symptoms is not an emergency; talk to your doctor within a few days.

Related tests

• Lab Test Guide: all tests
• Beta HCG Values
• Ovulation Test and LH
• FSH and LH Values
• Estradiol (E2) Values
• High Prolactin

What changed? (October 2026)

• New page: based on NICE NG126 (June 2026 update), NICE NG257 (March 2026) and the PERİDER-TJOD 2025 threatened miscarriage guideline.
• ASRM's 2026 opinion on luteal phase deficiency was reflected.

Sources

• Demir SC, Polat İ, Şahin D et al. PERİDER-TJOD düşük tehdidi ve tedavisi kılavuzu. Turk J Obstet Gynecol 2025;22:96-105. https://doi.org/10.4274/tjod.galenos.2025.36926 (accessed October 2, 2026)
• T.C. Sağlık Bakanlığı SHGM. Tıbbi Biyokimya Toplam Test Süreci Rehberi. May 2024, Publication No 1287. https://dosyamerkez.saglik.gov.tr/Eklenti/48692/0/tibbi-biyokimya-toplam-test-sureci-rehberipdf.pdf (accessed October 2, 2026)
• Türkiye Endokrinoloji ve Metabolizma Derneği (TEMD). Adrenal ve Gonadal Hastalıklar Kılavuzu. 2025. https://file.temd.org.tr/Uploads/publications/guides/documents/AdrenalKilavuz2025.pdf (accessed October 2, 2026)
• T.C. Sağlık Bakanlığı. e-Nabız Kullanım Kılavuzu V2.1. 2025. https://enabiz.gov.tr/document/User_Manual.pdf (accessed October 2, 2026)
• NICE. Ectopic pregnancy and miscarriage: diagnosis and initial management (NG126). 2019, last updated June 17, 2026. https://www.nice.org.uk/guidance/ng126 (accessed October 2, 2026)
• NICE. Fertility problems: assessment and treatment (NG257). March 31, 2026. https://www.nice.org.uk/guidance/ng257 (accessed October 2, 2026)
• Practice Committee of the American Society for Reproductive Medicine. Fertility evaluation of infertile women: a committee opinion. Fertil Steril 2021;116:1255-1265. https://doi.org/10.1016/j.fertnstert.2021.08.038 (accessed October 2, 2026)
• Practice Committee of the American Society for Reproductive Medicine. Diagnosis and treatment of luteal phase deficiency: a Committee Opinion. Fertil Steril 2026;126:633-639. https://doi.org/10.1016/j.fertnstert.2026.06.014 (accessed October 2, 2026)
• Teede HJ et al. Recommendations From the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. J Clin Endocrinol Metab 2023;108(10):2447-2469. https://doi.org/10.1210/clinem/dgad463 (accessed October 2, 2026)
• Michigan Medicine Laboratories (MLabs). Progesterone; MU Health Care Laboratory Test Catalog. Progesterone Level. Current versions. https://mlabs.umich.edu/tests/progesterone and https://muhealth.testcatalog.org/show/Progest (accessed October 2, 2026)