The beta hCG test is the blood pregnancy test performed after an IVF embryo transfer. The findings of this test can be used to determine a baby’s chances of success. We’ll examine the data’s findings about varied beta levels in this piece. (1)
What does high beta hCG mean?
Multiples (twins or triplets) may be indicated by a high beta hCG level, which will be verified by an ultrasound. According to one study, women having twins had median hCG levels at day 13 after receiving a fresh embryo transfer of 544 and 329 respectively.
An unusually high beta hCG level could also be caused by other medical conditions. Your doctor will analyze the findings and discuss the next steps if there are any areas of concern.
What does low beta hCG mean?
Remember that many normal, healthy pregnancies begin with low beta hCG levels despite the alarming evidence on outcomes from low beta hCG levels. This can indicate a slower implantation process for the embryo.
Avoid getting too fixated on hCG levels. Compared to hCG levels, ultrasound results are a far better predictor of pregnancy outcomes. If you are worried about your beta hCG values, talk to your doctor right away. Ask them their thoughts on the situation and what they believe your odds of success are in light of the information at hand.
What is the normal hCG level after IVF?
There is no specific hCG level or amount that signifies a healthy pregnancy. Beta hCG varies depending on the type of embryo you transferred (was it fresh? Was it frozen?) and when the test was done. A beta hCG level above 100 is typically seen as a good result.
But the rate of rise over time is more significant than the actual beta number (it should double every 48 hours). The chance of success increases with the amount of hCG that has increased two days after the first beta. The fact that the number considerably rises over time is more significant than the absolute beta value.
Typically, there are three beta hCG tests (assuming the first and second are positive). After that, you’ll get a vaginal ultrasound every five to eight weeks to confirm your pregnancy by checking for a heartbeat and a gestational sac. More accurately than hCG levels, this ultrasound predicts the outcome of the pregnancy. So, if your first beta is low, don’t get alarmed.
What should the hCG level be 12 days after the embryo transfer? And 14 days later?
A strong beta count (14dp3dt or 12dp5dt) will be over 200 mIU/mL (or IU/L, equivalent) 17 days after fertilization.
According to a study involving 523 IVF pregnancies, betas above 200 IU/L now have the best probability of being successful.
In this study, singleton pregnant women with low serum hCG levels had higher rates of early pregnancy loss and ectopic pregnancy (one baby only).
What do studies say?
Quantitative serum hCG level 14 days after embryo transfer (ET) has been reported to be associated with pregnancy outcomes and the possibility of multiple pregnancies. A prospective study was conducted to evaluate the predictive value of the 14-day hCG level after ET with pregnancy outcome and multiple pregnancies.
Consequently, it supports the hypothesis that hCG levels greater than 200 mIU/ml at day 14 post-ET are more likely to have ongoing pregnancies; hCG levels greater than 600 have been shown to have a higher probability of multiple pregnancies. (2)
Factors Affecting Beta hCG Levels
First, the number of embryos transferred plays a significant role. Higher hCG levels often signal the presence of multiples, such as twins or triplets. Consequently, the day of embryo transfer is another determinant. Typically, blastocyst transfers, involving more developed embryos, might exhibit slightly elevated initial hCG levels compared to cleavage stage transfers. Furthermore, the timing of implantation affects these levels. The embryo’s implantation a few days post-transfer could result in later rises in hCG levels. Moreover, lab variability cannot be overlooked. Different laboratories may report slightly varied ranges for what constitutes normal hCG levels.
Crucially, the rate of increase in hCG levels emerges as the most critical factor. Ideal scenarios witness a doubling of hCG levels every 48 hours in the initial stages of pregnancy. This pattern is a reassuring sign of a viable pregnancy. Therefore, while numerous factors can affect initial hCG readings:
- The presence of multiples
- Stage of embryo at transfer
- Implantation timing
- Laboratory measurement variances
The emphasis remains on the consistency and pattern of hCG level escalation. This nuanced understanding assists in navigating the complexities of early pregnancy following IVF.
Source:
2- Guth, B., Hudelson, J., Higbie, J., Solomon, B., Polley, S., Thomas, S., & Gentry, W. L. (1995). Predictive value of hCG level 14 days after embryo transfer. Journal of assisted reproduction and genetics, 12, 13-14.
