Specifically, twin and multiple pregnancies can have 30% to 50% higher hCG levels than singleton pregnancies at the same point in early pregnancy. Even so, detection of high hCG levels alone can't reliably predict twin pregnancies.
Some women have very low levels of hCG, but progress to delivering perfectly healthy and normal babies. Others have very high, elevated levels which may alert their healthcare provider to suspect a mother is pregnant with twins or triplets. But in fact, she may be carrying just one baby.
The range for singletons is 5 – 397 and for twins it is 48 – 683. As you can see, there is a big overlap between the first hCG level in singleton and twins. What this means is that even if you have a first hCG level of 397, it could be a singleton pregnancy.
If you get a positive test, especially a really dark positive, days before your period is even due, that may be one of the early signs of twins!
Sometimes with multiples, there is a higher, early trend in hCG levels. Twin and multiple pregnancies may also have 30-50% higher hCG levels than for one baby. Measuring hCG levels for twins cannot confirm the presence of twins, it's only when twins are seen on ultrasound that they can be accurately diagnosed.
Sometimes. There can be a higher initial hCG trend increase with multiples, says Maureen Baldwin, M.D., MPH, an assistant professor of Obstetrics and Gynecology at Oregon Health and Science University.
However, the information on twin pregnancies has shown that baseline hCG levels are higher compared to singleton pregnancies—though the rate of increase is similar.
An immediate dark positive result could mean that there's a high concentration of hCG in your urine, and the test is showing an immediate dark result due to the hormone level. One thing to note is that all home pregnancy tests are different and may detect hCG at different levels.
You cannot conclusively distinguish a single pregnancy from twins on a urine pregnancy test. That said, you may have a very early positive pregnancy test if you are carrying twins.
RESULTS: The median free β-human chorionic gonadotropin and pregnancy-associated plasma protein A levels in cases of Down syndrome was 2.09 (95% confidence interval 1.69 to 2.62) and 0.405 multiples of the median (95% confidence interval 0.28 to 0.67), respectively.
They also stated that the greatest concentration of maternal urinary hCG was present from the 6th to the 14th week of pregnancy when nausea and vomiting were mostly encountered.
Background: Maternal serum HCG (MSHCG) is higher when the fetus is a female than when it is male. This has been demonstrated in the second and third trimesters of pregnancy, and recently at 10-14 weeks gestation.
The hCG levels in female-bearing pregnancies increase significantly, whereas they decrease in male-bearing pregnancies [1–3].
Your hCG levels rise fast and peak around 10 weeks of pregnancy. After that, they fall gradually until childbirth. In rare cases, germ cell tumors or other cancers may cause your body to produce hCG.
Well, in pregnant women with twins, the HCG hormone in early pregnancy is very high. High levels of HCG in early pregnancy prevent antibodies from binding to the hormone, so when a test pack is checked, the results are negative. This condition is known as the prozone effect.
Too much hCG in the urine
Let's find out why. Having twins, triplets, or more can cause the body to produce higher levels of hCG. This could be the reason why some women might find themselves three months pregnant with a negative pregnancy test (yes, really!).
Although the line should be darker in relation to higher concentrations of hCG, the actual amount of hCG in a sample of urine can vary. This fluctuation is due in large part to the concentration of your urine at any given time.
However, you don't need to stress too much about taking a pregnancy test at a specific time of day. Using urine later on when it's less concentrated may only “hypothetically delay a positive result by only 12 to 24 hours,” advises Dr. Flanagan.
Different Line Colors
When taking a pregnancy test, any line in the test indication area is considered a positive pregnancy test, even if it is lighter than the control line. The darker line is usually the control line. Sometimes this second line is so faint, you can barely see it.
Having a dark test line one day and a very light test line the next day is not a sign of miscarriage, but more likely an indicator of how much water you have had to drink that day. You may be tempted to take multiple pregnancy tests over the next few days to make sure that the result is real.
If the test result is 'Pregnant' a numerical result: "1-2", "2-3" or "3+", is also displayed indicating that conception occurred 1 to 2 weeks ago, 2 to 3 weeks ago or 3 or more weeks ago.
The average early ß-hCG rise is significantly lower in vanishing twin pregnancies than non-vanished singletons and twins; however, it is still within clinically accepted normal limits. Twins arresting at an earlier developmental stage may have further reduced early rises.