Could it be twins?
Q: I am 18 DPO and my serum hCG is 556. Could this mean I have twins?
A: A serum hCG of 556 mIU/mL at 18 DPO is normal both for one or two fetuses. You could have twins, but you can't really tell from the serum hCG value alone. At 18 DPO the serum hCG for singletons is normally between about 70 and 750 mIU/mL, and for twins it can be between 200 and about 1750 mIU/ml.
Twins When HCG Increasing Too Fast
There is no sufficient scientific evidence that with twins there is always a faster-than-usual rise in hCG. Normal hCG values can vary up to 20 times in normal pregnancies. Variations in hCG increases are not necessarily a sign that the pregnancy is abnormal or that there are two or more fetuses.
|NORMAL TWIN PREGNANCIES||NORMAL SINGLE PREGNANCIES|
|Day after LH or HCG||Average||High||Low||Average||High||Low|