Beta-hCG (β-hCG) is the hormone measured in early pregnancy tests.
Here’s how it relates to twin pregnancies:
Typical pattern in a single pregnancy
•At about 4 weeks from the last period, β-hCG is usually 5–426 mIU/mL.
•It roughly doubles every 48–72 hours during the first few weeks.
With twins (or other multiples)
•Levels can be higher than average—often 30–50% higher, and sometimes even more—because two placentas are making the hormone.
•For example, if a single pregnancy might show 2,000 mIU/mL at 5 weeks, twins might be anywhere from the high end of the normal range to several thousand higher.
⚠️ Important points
•Wide overlap: A single pregnancy can also have high numbers, and a twin pregnancy can have numbers in the “single-baby” range.
•Diagnosis: Only an ultrasound (usually around 6–7 weeks) can confirm twins by visualizing two gestational sacs or heartbeats.
•Doctors usually use rising patterns of hCG together with ultrasound, not hCG alone, to assess pregnancy health and number of embryos.
Next Steps
Get a scan done around 6 weeks