hCG Levels & Pregnancy: How Far Along Are You?

Serum β-hCG correlates roughly with gestational age but varies widely. Levels typically double every 48–72 hours in early viable pregnancy.

Reference Ranges (from LMP)

Weeks	hCG (mIU/mL)
3	5–50
4	50–400
5	100–5,000
6	1,000–10,000
7–8	10,000–100,000

An hCG of 137 mIU/mL suggests ~4 weeks 2 days, but a single value cannot date pregnancy. Serial measurements and transvaginal ultrasound (≥1,500–2,000 mIU/mL discriminatory zone) are required for accurate dating and viability assessment.

Clinical Pearls

• Ectopic pregnancy: slower rise, plateau, or decline.
• Molar pregnancy: excessively high levels.
• Multiple gestation: higher levels for dates.

Always correlate with clinical context and imaging.